View source for Timeline of the far future

{{update|date=February 2024}}
[[File:Red Giant Earth warm.jpg|thumb|274x274px|alt= A dark gray and red sphere representing the Earth lies against a black background to the right of an orange circular object representing the Sun| Artist's idea of the [[Earth]] several billion years from now, when the [[Sun]] is a [[red giant]].]]

The ultimate fate of our [[universe]] may be the [[heat death of the universe]] or the [[big rip]]. Before that happens, it is possible to predict that the following will happen.

Some types of [[science]] can say what could happen far into the future.<ref>{{cite book| author= Rescher, Nicholas|  title = Predicting the future: An introduction to the theory of forecasting| url= https://archive.org/details/predictingfuture0000resc| date = 1998| publisher = State University of New York Press| isbn = 978-0791435533}}</ref> It is worth noting that our [[local group|local group of galaxies]] are bound by [[gravitation]], and its changes and aging can be discussed separate from the rest of the universe.

[[Astrophysics]] can say how [[planet]]s and [[star]]s form, affect each other, and die; [[particle physics]] can say how [[atom]]s and other matter act over time; [[evolutionary biology]] can allow us to see how living things change over time; and [[plate tectonics]] can say how [[Continent|continents]] move over time.  By observing the past and present, astrophysicists, particle physicists, evolutionary biologists and geologists can make [[Guess|guesses]] about what might happen in the future.

The [[second law of thermodynamics]] is important to predictions about the future of Earth, of the Solar System, and the future of the expanding [[universe]]. The second law of thermodynamics says that [[entropy]] is always happening.  That means that the universe is slowly running out of the kind of energy that can do [[work (physics)|work]].<ref name="Nave"/> For example, stars will eventually run out of [[hydrogen]] fuel and burn out.<ref name="five ages"/>

==<span id=Legend>Key</span>==

{| class="wikitable"
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| [[Astronomy]] and [[astrophysics]]
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| [[Geology]] and [[planetary science]]
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt=Biology|Biology]]
| [[Biology]]
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| [[Particle physics]]
|-
| style="background: #e0ffff;" | [[File:Greek lc pi icon.svg|16px|alt=Mathematics|Mathematics]]
| [[Mathematics]]
|-
| [[File:Aiga toiletsq men.svg|10px|alt=Technology and culture|Technology and culture]]
| [[Technology]] and [[culture]]
|}

==Earth, the Solar System and the universe==
[[Erosion]] is when wind, water or other things make a rock or mountain shrink by breaking of tiny pieces of it off over time.{{See also| Formation and evolution of the Solar System}}
{| class="wikitable" style="width: 100%; margin-right: 0;"
|-
! scope="col" | [[File:Key.svg|24px]]
! scope="col" | Years from now
! scope="col" | Event

|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 10,000
| If the [[Wilkes Subglacial Basin]] "ice plug" fails in the next few centuries in a way that makes the [[East Antarctic Ice Sheet]] fall, it will take up to this long for the sheet to melt completely. [[Sea level]]s would rise 3 to 4 meters.<ref>{{cite journal|last= Mengel|first= M.|author2= A. Levermann |title= Ice plug prevents irreversible discharge from East Antarctica|journal= Nature Climate Change|volume= 4|issue= 6|pages= 451–455|date= 4 May 2014|bibcode= 2014NatCC...4..451M|doi= 10.1038/nclimate2226}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 10,000<ref name=prob group=note>This represents the time by which the event will most probably have happened. It may occur randomly at any time from the present.</ref>
| The [[red supergiant star]] [[Antares]] will have exploded in a [[supernova]] by this time.<ref name=hockey>{{cite journal|bibcode= 2010Obs...130..167H|title= Public reaction to a V = −12.5 supernova|journal= The Observatory|volume= 130|issue= 3|page= 167|last1= Hockey|first1= T.|last2= Trimble|first2= V.|year= 2010}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 13,000
| By this point, halfway through the precessional cycle, Earth's [[axial tilt]] will be reversed, causing [[summer]] and [[winter]] to occur on opposite sides of Earth's orbit. This means that winters will be colder and summers will be hotter in the [[northern hemisphere]]. This is because the northern hemisphere will be facing towards the Sun [[Perihelion and aphelion|when Earth is closest to the Sun]] and away from the Sun [[Perihelion and aphelion|when Earth is furthest away from the Sun]].<ref name="plait">
{{cite book | title = Bad Astronomy: Misconceptions and Misuses Revealed, from Astrology to the Moon Landing "Hoax" | author = Plait, Phil | authorlink=Phil Plait | publisher = John Wiley and Sons | date = 2002 | pages = [https://archive.org/details/badastronomymisc00plai_621/page/n65 55]–56| title-link = Bad Astronomy: Misconceptions and Misuses Revealed, from Astrology to the Moon Landing "Hoax" }}{{ISBN missing}}
</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 15,000
| According to the [[Sahara pump theory]], the [[precession]] of Earth's poles will move the [[North African Monsoon]] far enough north to convert the [[Sahara]] back to a tropical climate, [[Neolithic Subpluvial|as it had]] 5,000–10,000 years ago.<ref name="tropicalsahara1">{{cite web|last1= Mowat|first1= Laura|title= Africa's desert to become lush green tropics as monsoons MOVE to Sahara, scientists say|url= https://www.express.co.uk/news/world/828144/Climate-change-Africa-Sahel-Sahara-region-monsoon-rainfall-drought|website= Express.co.uk|accessdate= 23 March 2018|language= en|date= 14 July 2017}}</ref><ref name="tropicalsahara2">{{cite web|title= Orbit: Earth's Extraordinary Journey|url= http://mymultiplesclerosis.co.uk/btbb/gilf-kebir-the-great-barrier-nick-drake-wadi-bakht/|website= ExptU|accessdate= 23 March 2018|date= 23 December 2015|archive-url= https://web.archive.org/web/20180714131638/https://mymultiplesclerosis.co.uk/btbb/gilf-kebir-the-great-barrier-nick-drake-wadi-bakht/|archive-date= 14 July 2018|url-status= dead|df= dmy-all}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 17,000<ref name=prob group=note/>
| Best-guess recurrence rate for a "civilization-threatening" [[supervolcanic]] eruption large enough to throw up 1,000 gigatons of pyroclastic material.<ref>{{cite journal |title='Super-eruption' timing gets an update — and not in humanity's favour |url=https://www.nature.com/articles/d41586-017-07777-6 |accessdate=28 August 2020 |journal=Nature |date=30 November 2017 |volume=552 |issue=7683 |pages=8 |language=en |doi=10.1038/d41586-017-07777-6|pmid=32080527 |s2cid=4461626 }}</ref><ref>{{cite news |title=Scientists predict a volcanic eruption that would destroy humanity could happen sooner than previously thought |url=https://www.independent.co.uk/news/science/volcano-super-eruption-apocalypse-wipe-out-life-human-kind-timeline-how-long-a8082006.html |accessdate=28 August 2020 |work=www.independent.co.uk |language=en}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 25,000
| The northern [[Martian polar ice caps|Martian polar ice cap]] could recede as [[Mars]] becomes warmer during its c. 50,000-year [[Apsidal precession|perihelion precession]] aspect of its [[Milankovitch cycles|Milankovitch cycle]].<ref>{{cite journal|last= Schorghofer |first= Norbert |title= Temperature response of Mars to Milankovitch cycles |journal= Geophysical Research Letters |date= 23 September 2008 |volume= 35 |issue= 18 |page= L18201 |doi= 10.1029/2008GL034954 |url= http://www.ifa.hawaii.edu/~norb1/Papers/2008-milank.pdf |archive-url= https://web.archive.org/web/20090919133851/http://www.ifa.hawaii.edu/~norb1/Papers/2008-milank.pdf |url-status= dead |archive-date= 19 September 2009 |bibcode= 2008GeoRL..3518201S |s2cid= 16598911 }}</ref><ref>{{cite book|last= Beech|first= Martin|title= Terraforming: The Creating of Habitable Worlds|date= 2009|publisher= Springer|pages= 138–142|bibcode= 2009tchw.book.....B}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 36,000
| The small [[red dwarf]] [[Ross 248]] will travel within 3.024 light-years of Earth. It will become the closest star to the Sun.<ref name="Matthews1993"/> It will recede after about 8,000 years. Then [[Alpha Centauri]] and then [[Gliese 445]] will be the nearest stars again<ref name="Matthews1993"/> ([[List of nearest stars and brown dwarfs#Distant future and past encounters|see timeline]]).
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 50,000
| According to Berger and Loutre (2002), the current [[interglacial]] period will end,<ref name="Berger2002"/> sending the Earth back into an [[ice age]], even with [[global warming]].
According to more recent studies, however (2016), the effects of anthropogenic global warming may delay this otherwise expected glacial period by another 50,000 years.<ref>{{Cite web|title=Human-made climate change suppresses the next ice age — Potsdam Institute for Climate Impact Research|url=https://www.pik-potsdam.de/en/news/latest-news/human-made-climate-change-suppresses-the-next-ice-age|access-date=2020-10-21|website=www.pik-potsdam.de}}</ref>

[[Niagara Falls]] will have worn away the rock underneath it all the way to [[Lake Erie]], so it will not be a waterfall.<ref name="Niagara Parks"/>

The many [[glacial lake]]s of the [[Canadian Shield]] will have been erased by [[post-glacial rebound]] and erosion.<ref>{{cite book|last= Bastedo|first= Jamie|title= Shield Country: The Life and Times of the Oldest Piece of the Planet|date= 1994|publisher= Arctic Institute of North America of the University of Calgary|page= 202 | isbn = 9780919034792 | series = Komatik Series, ISSN 0840-4488 | volume = 4 | url = https://books.google.com/books?id=-KUfAQAAIAAJ}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 50,000
| The length of the [[Julian day|day used for astronomical timekeeping]] reaches about 86,401 [[International System of Units|SI]] seconds because [[tidal acceleration|lunar tides will have made the Earth's rotation slow down]].<ref name="arxiv1106_3141"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 100,000
| Many of the [[constellation]]s will look very different as the stars move.<ref name="Tapping 2005"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 100,000<ref name=prob group=note/>
| The [[hypergiant]] star [[VY Canis Majoris]] will likely have exploded in a [[supernova]].<ref name="Monnier Tuthill Lopez 1999"/>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt= Biology|Biology]]
| 100,000
|Native North American [[earthworm]]s, such as [[Megascolecidae]], will have spread north through the United States [[Upper Midwest]] to the [[Canada–United States border|Canada–US border]], recovering from the [[Laurentide Ice Sheet]] glaciation (38°N to 49°N), assuming a migration rate of 10&nbsp;meters per year.<ref>{{cite book|last1= Schaetzl|first1= Randall J.|last2= Anderson|first2= Sharon|title= Soils: Genesis and Geomorphology|url= https://archive.org/details/soilsgenesisgeom00scha|url-access= limited|date= 2005|publisher= Cambridge University Press|page= [https://archive.org/details/soilsgenesisgeom00scha/page/n120 105] | isbn = 9781139443463}}</ref> (Humans have already introduced [[invasive species|non-native]] [[invasive earthworms of North America]].)
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| >&nbsp;100,000
| As one of the [[long-term effects of global warming]], 10% of [[greenhouse gas|anthropogenic carbon dioxide]] will still remain in a stabilized atmosphere.<ref>{{Cite book |title= The Long Thaw: How Humans Are Changing the Next 100,000 Years of Earth's Climate |url= https://archive.org/details/longthawhowhuman00arch_317 |url-access= limited |author= David Archer |date= 2009 |page= [https://archive.org/details/longthawhowhuman00arch_317/page/n135 123] |publisher= [[Princeton University Press]] |isbn= 978-0-691-13654-7}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 250,000
| [[Lōʻihi Seamount|Lōʻihi]], the youngest volcano in the [[Hawaiian–Emperor seamount chain]], will rise above the surface of the ocean and become a new [[High island|volcanic island]].<ref name="havo"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| c. 300,000<ref name=prob group=note/>
| At some point in the next few hundred thousand years, the [[Wolf–Rayet star]] [[WR 104]] may explode in a [[supernova]]. There is a small chance WR 104 is spinning fast enough to produce a [[gamma-ray burst]], and an even smaller chance that the burst could harm life on Earth.<ref>{{cite journal | journal= The Astrophysical Journal |volume= 675 |number= 1 |arxiv= 0712.2111 |title= The Prototype Colliding-Wind Pinwheel WR 104 |first1= Peter |last1= Tuthill |first2= John |last2= Monnier |first3= Nicholas |last3= Lawrance |first4= William |last4= Danchi |first5= Stan |last5= Owocki |first6= Kenneth |last6= Gayley |year= 2008 |doi= 10.1086/527286 |bibcode= 2008ApJ...675..698T |pages= 698–710|s2cid= 119293391 }}</ref><ref><!-- this is a WP:RS due to tuthill being a subject-matter expert -->{{cite web|url=http://www.physics.usyd.edu.au/~gekko/pinwheel/tech_faq.html|title=WR 104: Technical Questions|last1=Tuthill|first1=Peter|accessdate=20 December 2015}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 500,000<ref name=prob group=note/>
|Earth will likely have been hit by an asteroid of roughly 1&nbsp;km in diameter, [[Asteroid impact avoidance|assuming that people cannot stop it]].<ref name="Bostrom 2002"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 500,000
| The rugged terrain of [[Badlands National Park]] in [[South Dakota]] will have eroded away completely.<ref>{{cite web|title= Badlands National Park – Nature & Science – Geologic Formations|url= http://www.nps.gov/badl/naturescience/geologicformations.htm}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 1 million
| [[Meteor Crater]], a large [[impact crater]] in [[Arizona]] considered the "freshest" of its kind, will have eroded away.<ref>{{cite book|last= Landstreet|first= John D.|title= Physical Processes in the Solar System: An introduction to the physics of asteroids, comets, moons and planets|date= 2003|publisher= Keenan & Darlington|page= 121 | isbn = 9780973205107 | url = https://books.google.com/books?id=Ads1AQAAIAAJ}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 1 million<ref name=prob group=note/>
| Longest estimated time until the [[red supergiant star]] [[Betelgeuse]] explodes in a [[supernova]]. For at least a few months, the supernova is expected be visible on Earth in daylight after the light reaches Earth.<ref name="betel"/><ref>{{cite news |title=A giant star is acting strange, and astronomers are buzzing |url=https://www.nationalgeographic.com/science/2019/12/betelgeuse-is-acting-strange-astronomers-are-buzzing-about-supernova/ |accessdate=15 March 2020 |work=National Geographic |date=26 December 2019 |language=en}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 1 million<ref name=prob group=note/>
| [[Desdemona (moon)|Desdemona]] and [[Cressida (moon)|Cressida]], moons of [[Uranus]], will likely have collided.<ref name=Uranus>{{cite web|title= Uranus's colliding moons|year= 2017|url= http://www.astronomy.com/news/2017/09/uranus-colliding-moons |publisher= astronomy.com|accessdate= 23 September 2017}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 1.28 ± 0.05 million
| The star [[Gliese 710]] will pass as close as 0.0676 [[parsec]]s—{{convert|0.221|ly|AU|abbr=off|lk=on}}<ref name="Bailer2018">{{cite journal|last1=Bailer-Jones|first1=C.A.L.|last2=Rybizki|first2=J |last3=Andrae|first3=R.|last4=Fouesnea|first4=M.|title=New stellar encounters discovered in the second Gaia data release|journal=Astronomy & Astrophysics|volume=616|pages=A37|date=2018|arxiv=1805.07581|bibcode=2018A&A...616A..37B|doi=10.1051/0004-6361/201833456|s2cid=56269929}}</ref> to the Sun before moving away. Its gravity will [[Perturbation (astronomy)|change]] things in the [[Oort cloud]], a ring of icy rocks orbiting at the edge of the Solar System.  That will make it seem more likely that a comet will hit something in the inner Solar System.<ref name="gliese"/>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt= Biology|Biology]]
| 2 million
| Estimated time for the [[coral reef]] ecosystems to return to normal after human-caused [[ocean acidification]]; the recovery of marine ecosystems after the acidification event that occurred about 65 million years ago took about this long.<ref>{{cite book|last= Goldstein|first= Natalie|title= Global Warming|date= 2009|publisher= Infobase Publishing|page= 53 | url = https://books.google.com/books?id=-uYkEBl6CWYC | isbn = 9780816067695 |quote= The last time acidification on this scale occurred (about 65 mya) it took more than 2 million years for corals and other marine organisms to recover; some scientists today believe, optimistically, that it could take tens of thousands of years for the ocean to regain the chemistry it had in preindustrial times.}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 2 million+
| The [[Grand Canyon]] will erode further, deepening slightly, but principally widening into a broad valley surrounding the [[Colorado River]].<ref>{{cite web|title= Grand Canyon – Geology – A dynamic place|url=https://www.nps.gov/grca/learn/nature/grca-geology.htm|website= Views of the National Parks|publisher= National Park Service}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 2.7 million
| Average orbital half-life of current [[Centaur (minor planet)|centaur planets]]. These planets are unstable due to gravity from [[outer planets]].<ref name="Horner2004a">{{cite journal
 |last1= Horner |first1 = J.
 |last2= Evans |first2= N.W. |last3= Bailey |first3= M. E.
 |title= Simulations of the Population of Centaurs I: The Bulk Statistics
 |date= 2004
 |arxiv= astro-ph/0407400
 |doi= 10.1111/j.1365-2966.2004.08240.x
 |journal= [[Monthly Notices of the Royal Astronomical Society]]
 |volume= 354|issue=3|pages=798–810 |bibcode=2004MNRAS.354..798H
|s2cid = 16002759
 }}</ref> See [[Centaur (minor planet)#Notable centaurs|predictions for notable centaurs]].
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 10 million
| The [[East African Rift]] valley will become much bwider and be flooded by the [[Red Sea]], causing a new ocean basin to divide the continent of [[Africa]]<ref name="rift"/> and the [[African Plate]] into the Nubian Plate and the [[Somali Plate]].
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt= Biology|Biology]]
| 10 million
| Estimated time for full recovery of [[biodiversity]] after a potential [[Holocene extinction]], if it were as large as the five previous [[extinction event|major extinction events]].<ref>{{cite journal|last1= Kirchner|first1= James W.|last2= Weil|authorlink1= James Kirchner|first2= Anne|title= Delayed biological recovery from extinctions throughout the fossil record|url= https://archive.org/details/sim_nature-uk_2000-03-09_404_6774/page/177|journal= Nature|date= 9 March 2000|volume= 404|pages= 177–180 |bibcode = 2000Natur.404..177K|doi= 10.1038/35004564|issue= 6774|pmid= 10724168|s2cid= 4428714}}</ref>

Even without a mass extinction, by this time most current species will have disappeared through the [[background extinction rate]], with many [[clade]]s gradually evolving into new forms.<ref>{{cite book|last= Wilson|first= Edward O.|title= The Diversity of Life|date= 1999|publisher= W.W. Norton & Company|page= 216 | isbn = 9780393319408 | url = https://books.google.com/books?id=FzPaB_6Pw4MC}}</ref><ref>
{{cite book
 | last1 = Wilson
 | first1 = Edward Osborne
 | author-link1 = Edward O. Wilson
 | year = 1992
 | chapter = The Human Impact
 | title = The Diversity of Life
 | url = https://books.google.com/books?id=VS7GeNorZE4C
 | location = London
 | publisher = Penguin UK
 | publication-date = 2001
 | page = 
 | isbn = 9780141931739
 | access-date = 15 March 2020
 | quote = 
}}
</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 10 million – 1 billion<ref name=prob group=note/>
| [[Cupid (moon)|Cupid]] and [[Belinda (moon)|Belinda]], moons of [[Uranus]], will likely have collided.<ref name=Uranus/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 25 million
| According to [[Christopher R. Scotese]], the movement of the [[San Andreas Fault]] will cause the [[Gulf of California]] to flood into the [[Central Valley (California)|Central Valley]]. This will form a new inland sea on the [[West Coast of the United States|West Coast]] of [[North America]].<ref name="scotese"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 50 million
| Maximum estimated time before the moon [[Phobos (moon)|Phobos]] crashes into [[Mars]].<ref name="Bills"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 50 million
| According to Christopher R. Scotese, the movement of the [[San Andreas Fault]] will move [[Los Angeles, California]] and [[San Francisco, California]] so that they will have to be one city if people still live there by then.<ref name="scotese"/> The Californian coast will begin to be subducted into the [[Aleutian Trench]].<ref name="trench"/>

Africa will crash into [[Eurasia]] and close the [[Mediterranean Basin]]. This will create a mountain range similar to the [[Himalayas]].<ref name="medi"/>

The peaks of the [[Appalachian Mountains]] will erode away<ref>{{cite encyclopedia | date = 2011 | title = Geology | encyclopedia = Encyclopedia of Appalachia | publisher = University of Tennessee Press | url = http://www.encyclopediaofappalachia.com/category.php?rec=2 | accessdate = 21 May 2014 | archiveurl = https://web.archive.org/web/20140521203455/http://www.encyclopediaofappalachia.com/category.php?rec=2 | archivedate = 21 May 2014 | url-status = dead | df = dmy-all }}</ref> if the weathering takes place at 5.7 [[Bubnoff unit]]s. The mountains will change in other ways too. The [[valley]]s will deepen twice as fast.<ref>{{cite journal|last1= Hancock|first1= Gregory|title= Summit erosion rates deduced from 10Be: Implications for relief production in the central Appalachians|journal= Geology|date= January 2007|volume= 35|issue= 1|page= 89|doi= 10.1130/g23147a.1 |url= http://pages.geo.wvu.edu/~kite/HancockKirwan2007SummitErosion.pdf|last2= Kirwan|first2= Matthew|bibcode= 2007Geo....35...89H}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 50–60 million
| The [[Canadian Rockies]] will erode away to a plain, assuming a rate of 60 [[Bubnoff unit]]s.<ref>{{cite book|last= Yorath|first=C. J.|title= Of rocks, mountains and Jasper: a visitor's guide to the geology of Jasper National Park|date= 2017|publisher= Dundurn Press|page= 30 | isbn = 9781459736122 | quote = [...] 'How long will the Rockies last?' [...] The numbers suggest that in about 50 to 60 million years the remaining mountains will be gone, and the park will be reduced to a rolling plain much like the Canadian prairies.}}</ref> The [[Southern Rocky Mountains|Southern Rockies]] in the United States are eroding at a somewhat slower rate.<ref>{{cite journal|last= Dethier|first= David P.|display-authors= 4|author2= Ouimet, W.|author3= Bierman, P. R.|author4= Rood, D. H.|author5= Balco, G.|title= Basins and bedrock: Spatial variation in 10Be erosion rates and increasing relief in the southern Rocky Mountains, USA|journal= Geology|date= 2014|volume= 42|issue= 2|pages= 167–170|url= http://noblegas.berkeley.edu/~balcs/pubs/Dethier_2014_Geology.pdf|bibcode= 2014Geo....42..167D|doi= 10.1130/G34922.1|access-date= 2020-10-28|archive-date= 2018-12-23|archive-url= https://web.archive.org/web/20181223151250/http://noblegas.berkeley.edu/~balcs/pubs/Dethier_2014_Geology.pdf|url-status= dead}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 50–400 million
| Estimated time for the Earth to naturally replenish its [[fossil fuel]] reserves.<ref>{{cite book|editor-last= Pimentel|editor-first= David|last= Patzek|first= Tad W.|author-link1= Tad Patzek|title= Biofuels, Solar and Wind as Renewable Energy Systems: Benefits and Risks|chapter= Can the Earth Deliver the Biomass-for-Fuel we Demand?|date= 2008|publisher= Springer | isbn = 9781402086533 | url = https://books.google.com/books?id=WNszUml_Wd4C}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 80 million
| The [[Hawaii (island)|Big Island]] will sink beneath the surface of the ocean. However, there will still be other Hawaiian islands by then.<ref>{{cite news|last= Perlman|first= David|title= Kiss that Hawaiian timeshare goodbye / Islands will sink in 80 million years|url= http://www.sfgate.com/news/article/Kiss-that-Hawaiian-timeshare-goodbye-Islands-2468202.php|newspaper= San Francisco Chronicle|date= 14 October 2006}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 100 million<ref name=prob group=note/>
| By this time, it is likely to have an [[asteroid]] about as big as the one that killed [[Cretaceous–Paleogene extinction event|some of the dinosaurs]] 66 million years ago that will likely hit the Earth, [[Asteroid-impact avoidance|if people cannot stop it]].<ref name="kpg1"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 100 million
| According to the Pangaea Proxima Model created by Christopher R. Scotese, the [[plate tectonics]] of the [[Atlantic Ocean]] will change, and the [[America|Americas]] will begin to move toward [[Africa]].<ref name="scotese"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 100 million
| The [[rings of Saturn]] will change or disappear.<ref>{{cite book|last= Lang|first= Kenneth R.|title= The Cambridge Guide to the Solar System|date= 2003|publisher= Cambridge University Press|page= [https://archive.org/details/cambridgeguideto0000lang/page/329 329] | isbn = 9780521813068 | url = https://archive.org/details/cambridgeguideto0000lang |url-access= registration| quote = [...] all the rings should collapse [...] in about 100 million years.}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 110 million
| The Sun will be 1% brighter than it is today.<ref>{{cite journal|title= Distant future of the Sun and Earth revisited |journal= Monthly Notices of the Royal Astronomical Society |volume= 386 |issue= 1 |pages= 155–63 |author= Schröder, K.-P. |author2= Connon Smith, Robert |date= 2008|arxiv= 0801.4031|bibcode= 2008MNRAS.386..155S|doi= 10.1111/j.1365-2966.2008.13022.x|s2cid= 10073988 }}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 180 million
| A day on Earth will be one hour longer than it is today because the planet is slowly starting to slow down.<ref>{{cite web | title = How Long Until The Moon Slows The Earth to a 25 Hour Day? |author= Jillian Scudder | work= [[Forbes]] | url = https://www.forbes.com/sites/jillianscudder/2017/01/28/how-long-until-the-moon-slows-the-earth-to-a-25-hour-day/#477b64b16d32 | accessdate= 30 May 2017}}</ref>
|-
| style="background: #e0ffff;" | [[File:Greek lc pi icon.svg|16px|alt= Mathematics|Mathematics]]
| 230 million
| This is as far ahead as people can predict the orbits of the planets due to [[Lyapunov time]].<ref name="hayes07"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 240 million
| The [[Solar System]] will travel one whole [[Galactic year|orbit]] around the [[Galactic Center]].<ref name="galyear"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 250 million
|Due to plate tectonics, the coast of California is likely to have hit [[Alaska]] by this time.<ref name="scotese"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 250–350 million
| All the continents on Earth are likely fuse into a [[supercontinent]] by this time. Scientists have predicted the [[Amasia (continent)|Amasia]], [[Novopangaea]], and [[Pangaea Ultima]].<ref name="scotese"/><ref name="Williams Nield 2007"/> This will likely result in a glacial period, lowering sea levels and increasing oxygen levels, further lowering global temperatures.<ref>Calkin and Young in 1996 on pages 9–75</ref><ref name="ReferenceA"/>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt= Biology|Biology]]
| >250 million
| Rapid [[biological evolution]] may occur if this supercontinent forms, causing lower temperatures and higher oxygen levels.<ref name="ReferenceA">Thompson and Perry in 1997 on pages 127–28</ref> Increased competition between species due to the formation of a supercontinent, increased volcanic activity and less hospitable conditions due to global warming from a brighter Sun could result in a mass extinction event from which plant and animal life may not fully recover.<ref name=swansong2>{{cite journal|title= Swansong Biosphere II: The final signs of life on terrestrial planets near the end of their habitable lifetimes |journal= International Journal of Astrobiology |volume= 13 |issue= 3 |pages= 229–243 |author= O'Malley-James, Jack T. |author2= Greaves, Jane S. |author3= Raven, John A. |author4= Cockell, Charles S.|date= 2014 | arxiv= 1310.4841 |bibcode= 2014IJAsB..13..229O |doi= 10.1017/S1473550413000426|s2cid= 119252386 }}</ref>
|-
|style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 300 million
| Due to a shift in the equatorial Hadley cells to roughly 40° north and south, the amount of arid land will increase by 25%.<ref name=swansong2/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 300–600 million
| Estimated time for [[Venus]]'s mantle temperature to reach its maximum. Then, over a period of about 100 million years, major subduction occurs and the crust is recycled.<ref name="Strom1994">{{cite journal |last= Strom |first= Robert G. |author2= Schaber, Gerald G. |author3= Dawson, Douglas D. |date= 25 May 1994 |title= The global resurfacing of Venus |journal= [[Journal of Geophysical Research]] |volume= 99 |issue= E5 |pages= 10899–10926 |doi= 10.1029/94JE00388 |bibcode= 1994JGR....9910899S|s2cid= 127759323 |url= https://zenodo.org/record/1231347 }}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 350 million
| According to the extroversion model first developed by [[Paul F. Hoffman]], the plate tectonics of the [[Pacific Ocean]] will change: its subduction will stop.<ref>Nield in 2007 on pages 20–21</ref><ref>Hoffman in 1992 on pages 323–27</ref><ref name="Williams Nield 2007"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 400–500 million
| The supercontinent (Pangaea Ultima, Novopangaea, or Amasia) will likely separate into other continents again.<ref name="Williams Nield 2007"/> This will likely result in higher global temperatures, similar to the [[Cretaceous]] period.<ref name="ReferenceA"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 500 million<ref name=prob group=note/>
| Estimated time until a [[gamma-ray burst]], or massive, hyperenergetic supernova, occurs within 6,500 light-years of Earth; close enough for its rays to affect Earth's [[ozone layer]] and potentially trigger a [[Extinction event|mass extinction]]. This assumes that an explosion like this one caused the [[Ordovician–Silurian extinction events|Ordovician–Silurian extinction event]]. However, the supernova would have to be in exactly the right place and angle to have any negative effect.<ref name="natgeo"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 600 million
| [[Tidal acceleration]] moves the [[Moon]] far enough from Earth that it can no longer cause a total [[solar eclipse]].<ref name="600mil"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 500–600 million
| The Sun's increasing luminosity begins to disrupt the [[carbonate–silicate cycle]]; higher luminosity increases [[weathering]] of surface rocks, which traps [[carbon dioxide]] in the ground as carbonate. As water evaporates from the Earth's surface, rocks harden, causing [[plate tectonics]] to slow down and eventually stop once the oceans evaporate completely. With less volcanism to recycle carbon into the Earth's atmosphere, carbon dioxide levels begin to fall.<ref name=swansong>{{cite journal|title= Swansong Biospheres: Refuges for life and novel microbial biospheres on terrestrial planets near the end of their habitable lifetimes |journal= International Journal of Astrobiology |volume= 12 |issue= 2 |pages= 99–112 |author= O'Malley-James, Jack T. |author2= Greaves, Jane S. |author3= Raven, John A. |author4= Cockell, Charles S.|date= 2012 | arxiv= 1210.5721 |bibcode= 2013IJAsB..12...99O |doi= 10.1017/S147355041200047X|s2cid= 73722450 }}</ref> By this time, carbon dioxide levels will fall to the point at which [[C3 carbon fixation|{{C3}} photosynthesis]] is no longer possible. All plants that utilize {{C3}} photosynthesis (≈99 percent of present-day species) will die.<ref name="Heath Doyle 2009"/> The extinction of {{C3}} plant life is likely to be a long-term decline rather than a sharp drop. It is likely that plant groups will die one by one well before the critical [[carbon dioxide]] level is reached. The first plants to disappear will be {{C3}} [[herbaceous]] plants, followed by [[deciduous]] forests, [[evergreen]] broad-leaf forests and finally evergreen [[conifer]]s.<ref name=swansong2/>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt= Biology|Biology]]
| 500–800 million<ref name=prob group=note/>
| As the Earth begins to quickly heat up and carbon dioxide levels fall, plants and animals could survive longer by evolving other strategies such as requiring less carbon dioxide for photosynthesis, becoming [[Carnivorous plant|carnivorous]], adapting to [[desiccation]], or [[mycoheterotrophy|associating with]] [[fungi]]. These adaptations are likely to appear near the beginning of the moist greenhouse.<ref name=swansong2/> The death of most [[plant life]] will result in less [[oxygen]] in the [[atmosphere]], allowing for more [[DNA]]-damaging [[ultraviolet radiation]] to reach the surface. The rising temperatures will increase chemical reactions in the atmosphere, which will mean there will be even less oxygen. Flying animals would be much better off because of their ability to travel large distances looking for cooler temperatures.<ref name=WB11728>Ward & Brownlee in 2003 on pages 117-28</ref> Many animals may be driven to the poles or possibly underground. These creatures would become active during the [[polar night]] and [[aestivate]] during the [[polar day]] due to the intense heat and radiation. Much of the land would become a barren desert, and plants and animals would primarily be found in the oceans.<ref name=WB11728/>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt= Biology|Biology]]
| 800–900 million
| Carbon dioxide levels fall to the point at which [[C4 carbon fixation|{{C4}} photosynthesis]] is no longer possible.<ref name="Heath Doyle 2009"/> Without plant life to recycle oxygen in the atmosphere, free oxygen and the ozone layer will disappear from the atmosphere allowing for intense levels of deadly UV light to reach the surface. In the book ''The Life and Death of Planet Earth'', authors [[Peter D. Ward]] and [[Donald Brownlee]] state that some animal life may be able to survive in the oceans. Eventually, however, all multicellular life will die out.<ref name="bd2_6_1665"/> At most, animal life could survive about 100 million years after plant life dies out, with the last animals being animals that do not depend on living plants such as [[termite]]s or those near [[hydrothermal vent]]s such as [[worm]]s of the genus ''[[Riftia]]''.<ref name=swansong2/> The only life left on the Earth after this will be single-celled organisms.
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 1 billion<ref name="shortscale" group=note>Units are [[short scale]]</ref>
| 27% of the ocean's mass will have been subducted into the mantle. If this were to continue uninterrupted, it would reach an equilibrium where 65% of present-day surface water would be subducted.<ref name=hess5_4_569/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 1.1 billion
| The Sun will be 10% brighter than it is today, causing the Earth's surface temperatures to reach an average of around {{cvt|320|K|C F}}. The atmosphere will become a "moist greenhouse," which will make the oceans evaporate.<ref name="swansong"/><ref name="mnras386_1"/> This would cause [[plate tectonics]] to stop completely, if not already stopped before this time.{{sfn|Brownlee|2010|p=95}} Pockets of water may still be present at the poles, allowing a place for very simple life to live.<ref name="abode"/><ref name="pressure"/>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt= Biology|Biology]]
| 1.2 billion
| High estimate until all plant life dies out, assuming some form of photosynthesis is possible despite extremely low carbon dioxide levels. If this is possible, rising temperatures will make any animal life unsustainable from this point on.<ref name=nature>{{cite journal|title= The life span of the biosphere revisited |journal= Nature |volume= 360 |issue= 6406 |pages= 721–23 |author= Caldeira, Ken |author2= Kasting, James F|date=1992|bibcode= 1992Natur.360..721C|doi=10.1038/360721a0|pmid=11536510|s2cid= 4360963 }}</ref><ref name=tellus_b_52_1>{{cite journal|title= Reduction of biosphere life span as a consequence of geodynamics |journal= Tellus B |volume= 52 |issue= 1 |pages= 94–107 |author= Franck, S.|date= 2000 |bibcode= 2000TellB..52...94F|doi= 10.1034/j.1600-0889.2000.00898.x}}</ref><ref name=grl28_9>{{cite journal |title= Biotic feedback extends the life span of the biosphere |journal= Geophysical Research Letters |volume= 28 |issue= 9 |pages= 1715–18 |author= Timothy M, von Bloh |author2= Werner|date= 2001 |bibcode= 2001GeoRL..28.1715L|doi= 10.1029/2000GL012198|s2cid= 16152753 }}</ref>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt= Biology|Biology]]
| 1.3 billion
| [[Eukaryotic]] life dies out on Earth due to carbon dioxide starvation. Only [[prokaryote]]s, such as [[bacteria]], are still there.<ref name="bd2_6_1665"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 1.5–1.6 billion
|The Sun's rising luminosity causes its [[circumstellar habitable zone]] to move outwards; as [[carbon dioxide]] rises in [[Mars]]'s atmosphere, its surface temperature rises to levels akin to Earth during the [[ice age]].<ref name="bd2_6_1665"/><ref name="mars"/>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt= Biology|Biology]]
| 1.6 billion
| Lower estimate until all prokaryotic life on Earth will go extinct.<ref name=bd2_6_1665/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 2 billion
| High estimate until the Earth's oceans evaporate if the atmospheric pressure were to decrease via the [[nitrogen cycle]].<ref name=pnas106_24/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 2.3 billion
| The Earth's [[outer core]] freezes if the [[inner core]] continues to grow at its current rate of {{cvt|1|mm}} per year.<ref name="ng4_264"/><ref name="compo"/> Without its liquid outer core, the [[Earth's magnetic field]] shuts down,<ref name="magnet"/> and charged particles emanating from the [[Sun]] gradually deplete the atmosphere.<ref>{{cite journal |title= Solar wind hammers the ozone layer |journal= News@nature |author= Quirin Shlermeler|date= 3 March 2005 | doi= 10.1038/news050228-12 }}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 2.55 billion
| The Sun will have become the hottest it can be: 5,820 K. From then on, it will become cooler even though it will become brighter.<ref name="mnras386_1"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 2.8 billion
| Earth's surface temperature will reach around {{cvt|420|K|C F}}, even at the poles.<ref name=swansong/><ref name="global1"/>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt= Biology|Biology]]
| 2.8 billion
| All life, which by then will be only single-celled living things in microenvironments such as high-altitude lakes or caves, will go extinct.<ref name=swansong/><ref name="global1"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| c. 3 billion<ref group="note" name="prob" />
| There is a roughly 1-in-100,000 chance that the Earth might be ejected into interstellar space by a stellar encounter before this point and a 1-in-3-million chance that it will then be captured by another star. Were this to happen, life, assuming it survived the interstellar journey, could potentially continue for far longer.{{sfn|Adams|2008|pp=33–44}}
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 3 billion
| [[Median]] point at which the Moon's increasing distance from the Earth means it can no longer keep Earth's [[axial tilt]] from changing too fast. Then, the Earth's [[true polar wander]] becomes chaotic and extreme, leading to dramatic shifts in the planet's climate due to the changing axial tilt.<ref name="wander"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt= Astronomy and astrophysics|Astronomy and astrophysics]]
| 3.3 billion
| There is a roughly 2% chance that [[Jupiter]]'s gravity may make [[Mercury (planet)|Mercury]]'s orbit so [[orbital eccentricity|eccentric]] as to collide with [[Venus]], sending the inner Solar System into chaos. Possible scenarios include Mercury colliding with the Sun, being ejected from the Solar System, or colliding with either Venus or the Earth.<ref name="chaos"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt= Geology and planetary science|Geology and planetary science]]
| 3.5–4.5 billion
| All water currently present in oceans (if not lost earlier) will disappear into the air. This will make the [[greenhouse effect]] much worse, and the Sun's will be 35-40% brighter than it is today, which will also make much it worse. This will make the Earth's {{cvt|1400|K|C F}}—hot enough to melt some surface rock.{{sfn|Brownlee|2010|p= 95}}<ref name="pnas106_24">{{cite journal | last1= Li | first1= King-Fai | last2= Pahlevan | first2= Kaveh | last3= Kirschvink | first3= Joseph L. | last4= Yung | first4= Yuk L. | date= 16 June 2009 | title= Atmospheric pressure as a natural climate regulator for a terrestrial planet with a biosphere | journal= Proceedings of the National Academy of Sciences of the United States of America| volume= 106 | issue= 24 | pages= 9576–9579 | doi= 10.1073/pnas.0809436106 | pmid= 19487662 | pmc= 2701016 | bibcode= 2009PNAS..106.9576L | doi-access= free }}</ref><ref name=guinan_ribas>{{cite journal | last1= Guinan | first1= E. F. | last2= Ribas | first2= I. | title= Our Changing Sun: The Role of Solar Nuclear Evolution and Magnetic Activity on Earth's Atmosphere and Climate | journal= ASP Conference Proceedings | volume= 269 | pages= 85–106 | editor1-last= Montesinos | editor1-first= Benjamin | editor2-last= Gimenez | editor2-first= Alvaro | editor3-last= Guinan | editor3-first= Edward F. | date= 2002 | bibcode= 2002ASPC..269...85G }}</ref><ref name=icarus74>{{cite journal | last1= Kasting | first1= J. F. | title= Runaway and moist greenhouse atmospheres and the evolution of earth and Venus | journal= Icarus | volume= 74 |date= June 1988 | issue= 3 | pages= 472–494 | doi= 10.1016/0019-1035(88)90116-9 | pmid= 11538226 | bibcode= 1988Icar...74..472K | url= https://zenodo.org/record/1253896 }}</ref> Many people say that the Earth's in this part of the future{{when|date=March 2020}} will be like [[Venus]] is today, but the temperature will really be around two times hotter than the temperature on Venus today. Earth will have a partially melted surface,<ref name="venus"/> but the surface of Venus right now is probably mostly solid. At this part of the future, Venus will also be much hotter than it is now.  Venus is closer to the Sun than Earth.
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 3.6 billion
| [[Neptune]]'s moon [[Triton (moon)|Triton]] will fall through the planet's [[Roche limit]], so it may break apart and become a [[ring system]] so that Neptune has [[Rings of Saturn|rings like Saturn]]'s.<ref name="triton"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 4 billion
| [[Median]] point by which the [[Andromeda Galaxy]] will have [[Andromeda–Milky Way collision|collided]] with the [[Milky Way]]. Then they would be one galaxy named "Milkomeda."<ref name="cox"/> There is also a small chance of the Solar System being ejected.<ref name=Cain>{{cite web|title=When Our Galaxy Smashes Into Andromeda, What Happens to the Sun?|author=Cain, Fraser | work=Universe Today|url=http://www.universetoday.com/2007/05/10/when-our-galaxy-smashes-into-andromeda-what-happens-to-the-sun/|date=2007|accessdate=2007-05-16| archiveurl= https://web.archive.org/web/20070517021426/http://www.universetoday.com/2007/05/10/when-our-galaxy-smashes-into-andromeda-what-happens-to-the-sun/| archivedate= 17 May 2007 | url-status= live}}</ref><ref name=Cox2008>{{cite journal|title=The Collision Between The Milky Way And Andromeda | author=Cox, T. J. | author2=Loeb, Abraham | journal=Monthly Notices of the Royal Astronomical Society | arxiv=0705.1170 | date=2008 | doi=10.1111/j.1365-2966.2008.13048.x|volume=386|issue=1 | pages=461–474 | bibcode=2008MNRAS.386..461C| s2cid=14964036 }}</ref> The planets of the Solar System will almost certainly not be disturbed by these events.<ref>{{cite web|url=http://www.nasa.gov/mission_pages/hubble/science/milky-way-collide.html |author=NASA|title=NASA's Hubble Shows Milky Way is Destined for Head-On Collision |website=NASA |date=31 May 2012 |accessdate=13 October 2012}}</ref><ref>{{cite news|last=Dowd|first=Maureen|title=Andromeda Is Coming!|url=https://www.nytimes.com/2012/05/30/opinion/dowd-andromeda-is-coming.html|accessdate=9 January 2014|newspaper=The New York Times|date=29 May 2012|quote=[NASA's David Morrison] explained that the [[Andromeda-Milky Way collision]] would just be two great big fuzzy balls of stars and mostly empty space passing through each other harmlessly over the course of millions of years.}}</ref><ref name="milk"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 4.5 billion
| Mars will reach the same [[solar flux]] as the Earth did when it first formed, 4.5 billion years ago from today.<ref name="mars"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 5.4 billion
| The Sun will run out of hydrogen to turn into helium. Therefore, the Sun will finish the [[main sequence]] of its life as a star. It will also begin to [[stellar evolution|evolve]] into a [[red giant]].<ref name="Schroder 2008"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 6.5 billion
| Mars will reach the same solar radiation flux as Earth has today. Then, all the things that happened to Earth, described above, will also happen to Mars.<ref name="mars"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 7.5 billion
| Earth and Mars may become [[tidally locked]] with the expanding subgiant Sun. That means the same side of Earth will face away from the Sun and the same side will face away from the Sun, so there is no more day or night.<ref name="mars"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 7.59 billion
| The Earth and Moon will probably be fall into the Sun just before the Sun reaches the tip of its [[red giant]] phase and its maximum radius of 256 times the size it has today.<ref name="Schroder 2008"/><ref name=earthredgiantsun group=note>This has been a tricky question for quite a while; see the 2001 paper by Rybicki, K. R. and Denis, C. However, according to the latest calculations, this happens with a very high degree of certainty.</ref> Before they fall into the Sun, the Moon might form spirals below Earth's [[Roche limit]] so that it breaks into a ring of debris, most of which will fall to the Earth's surface.<ref name="powell2007"/>
<!--
leaving this here in case later calculation(s) show the above not to be true-->

During this era, Saturn's moon [[Titan (moon)|Titan]] may reach surface temperatures necessary to support life.<ref name="Titan"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 7.9 billion
| The Sun will reach the tip of the red-giant branch of the [[Hertzsprung–Russell diagram]], meaning it will be the biggest and fattest it will ever be in its whole life, 256 times the present-day value.<ref name="Rybicki2001"/> In the process, [[Mercury (planet)|Mercury]], [[Venus]], very likely Earth and possibly Mars will be destroyed.<ref name="Schroder 2008"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 8 billion
| The Sun will become a carbon–oxygen [[white dwarf]] with about 54.05% its present mass.<ref name="Schroder 2008"/><ref name="nebula"/><ref name="apj676_1_594"/><ref name="dwarf group note">Based upon the weighted least-squares best fit on p. 16 of Kalirai et al. with the initial mass equal to a [[solar mass]].</ref> At this point, if the Earth somehow survives, it will become much colder very quickly because the white dwarf Sun will give off much less energy than the yellow dwarf Sun does today.
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 22 billion
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 50 billion
| If the Earth and Moon are not engulfed by the Sun, by this time they will become [[Tidal locking|tidally locked]], with each showing only one face to the other so that there is no more day or night.<ref name="tide1">
{{cite book |url=https://books.google.com/books?id=aU6vcy5L8GAC&pg=PA184| title = Solar System Dynamics | author = Murray, C.D. | author2 = Dermott, S.F. | name-list-style = amp | publisher = [[Cambridge University Press]] | date = 1999 | page = 184 | isbn = 978-0-521-57295-8
}}
</ref><ref name="tide2">
{{cite book | last = Dickinson | first = Terence | authorlink = Terence Dickinson | title = From the Big Bang to Planet X | url = https://archive.org/details/frombigbangtopla00unse | publisher = [[Camden House]] | date = 1993 | location = Camden East, Ontario | pages = [https://archive.org/details/frombigbangtopla00unse/page/79 79]–81 | isbn = 978-0-921820-71-0
}}
</ref> The tidal action of the white dwarf Sun will extract [[angular momentum]] from the system, causing the lunar orbit to decay and the Earth to spin faster and faster.<ref name="canup_righter">
{{cite book | first1 = Robin M. | last1 = Canup | first2 = Kevin | last2 = Righter | title = Origin of the Earth and Moon | volume = 30 | series=The University of Arizona space science series | publisher = University of Arizona Press | date = 2000 | isbn = 978-0-8165-2073-2 | pages = 176–177 | url = https://books.google.com/books?id=8i44zjcKm4EC&pg=PA176
}}
</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 65 billion
| The Moon may end up colliding with the Earth, assuming the Earth and Moon are not engulfed by the red giant Sun.<ref>{{cite web|url=https://www.forbes.com/sites/brucedorminey/2017/01/31/earth-and-moon-may-be-on-long-term-collision-course/#38a21ffa3c68|website=Forbes|first=Bruce |last=Dorminey |title=Earth and Moon May Be on Long-Term Collision Course|date=31 January 2017|accessdate=11 February 2017}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 100–150 billion
| The [[Metric expansion of space|Universe's expansion]] causes all galaxies beyond the former Milky Way's [[Local Group]] to disappear beyond the [[Particle horizon|cosmic light horizon]], so that anyone then living on or near Earth will [[not be able to tell they are there]].<ref name="galaxy"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 150 billion
| The [[cosmic microwave background]] will cool down from its current temperature of c. 2.7&nbsp;K to 0.3&nbsp;K, rendering it undetectable with current technology.<ref name="temp"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 325 billion
| Estimated time by which the expansion of the universe isolates all gravitationally bound structures within their own cosmological horizon. At this point, the universe will have expanded by more than 100 million times, and even individual exiled stars will be alone.<ref name=":0"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 450 billion
| [[Median]] point by which the c. 47 galaxies<ref name="messier"/> of the Local Group will come together into a single large galaxy.<ref name="dying"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 800&nbsp;billion
| Expected time when the net light emission from the combined Milkomeda galaxy will begins to decline as its [[red dwarf]] stars pass go through their [[blue dwarf (red-dwarf stage)|blue dwarf]] stage of peak luminosity.<ref name="bluedwarf"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 10<sup>12</sup> (1&nbsp;trillion)
| Low estimate for the time until [[star formation]] ends in galaxies as galaxies run out of [[gas cloud]]s that become stars.<ref name="dying"/>

The Universe's expansion, assuming a constant dark energy density, multiplies the wavelength of the cosmic microwave background by 10<sup>29</sup>, exceeding the scale of the [[cosmic light horizon]] and erasing any sign that the [[Big Bang]] happened. However, it may still be possible to tell how much the universe is expanding by studying [[Stellar kinematics|hypervelocity stars]].<ref name="galaxy"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 10<sup>11</sup>–10<sup>12</sup> (100&nbsp;billion – 1&nbsp;trillion)
| Estimated time until the Universe ends via the [[Big Crunch]], assuming a "closed" model.<ref name="Adams 1997 337–72">{{Cite journal
| last1         = Adams
| first1        = Fred C.
| author-link  = Fred Adams
| last2        = Laughlin
| first2       = Gregory
| author-link2 = Gregory P. Laughlin
| year         = 1997
| title        = A dying universe: the long-term fate and evolution of astrophysical objects
| journal      = [[Reviews of Modern Physics]]
| volume       = 69
| issue        = 2
| pages        = 337–72
|arxiv         = astro-ph/9701131
|bibcode       = 1997RvMP...69..337A
|doi           = 10.1103/RevModPhys.69.337
| s2cid = 12173790
}}</ref><ref>{{Cite journal |arxiv = astro-ph/0409264|doi = 10.1088/1475-7516/2004/12/006|bibcode = 2004JCAP...12..006W|title = Current observational constraints on cosmic doomsday|year = 2004|last1 = Wang|first1 = Yun|last2 = Kratochvil|first2 = Jan Michael|last3 = Linde|first3 = Andrei|last4 = Shmakova|first4 = Marina|journal = Journal of Cosmology and Astroparticle Physics|volume = 2004|issue = 12|pages = 006|s2cid = 56436935}}</ref> Depending on how long the expansion phase is, the events in the contraction phase will happen in the reverse order.<ref name="Davies1994">{{cite book |last=Davies |first=Paul |title=The Last Three Minutes: Conjectures About The Ultimate Fate of the Universe |publisher=[[Basic Books]] |year=1997 |isbn=978-0-465-03851-0}}</ref> Galaxy [[supercluster]]s would first merge, followed by [[galaxy cluster]]s and then later [[galaxy|galaxies]]. Eventually, [[star]]s will be so close together that they will begin to collide with each other. As the Universe continues to contract, the [[cosmic microwave background]] [[temperature]] will rise above the surface temperature of certain stars, which means that these stars will no longer be able to give off heat, slowly cooking themselves until they explode. It will begin with low-mass [[red dwarf]] stars once the CMB reaches {{convert|2400|K|C F}} around 500,000 years before the end, followed by [[Stellar classification|K-type, G-type, F-type, A-type, B-type and finally O-type]] stars around 100,000 years before the [[Big Crunch]]. Minutes before the Big Crunch, the temperature will be so great that [[atomic nuclei]] will disband and the particles will be sucked up by already tightening [[black hole]]s. Finally, all the black holes in the Universe will merge into one black hole containing all the [[matter]] in the universe, which would then devour the Universe, including itself.<ref name="Davies1994"/> After this, it is possible that a new Big Bang would happen and create a new universe. The observed actions of [[dark energy]] and the shape of the Universe do not support this scenario. It is thought that the Universe is flat and because of dark energy, the expansion of the universe will accelerate; however, the properties of dark energy are still not known, and thus it is possible that dark energy could reverse sometime in the future.
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 1.05×10<sup>12</sup> (1.05&nbsp;trillion)
| Estimated time by which the Universe will have expanded by a factor of more than 10<sup>26</sup>, reducing the average particle density to less than one particle per [[cosmological horizon]] volume. Beyond this point, particles of unbound intergalactic matter will all be separate from each other, and collisions between them will no longer affect the future evolution of the Universe.<ref name=":0">{{Cite journal|last1=Busha|first1=Michael T.|last2=Adams|first2=Fred C.|last3=Wechsler|first3=Risa H.|last4=Evrard|first4=August E.|date=2003-10-20|title=Future Evolution of Structure in an Accelerating Universe|journal=The Astrophysical Journal|volume=596|issue=2|pages=713–724|doi=10.1086/378043|arxiv=astro-ph/0305211|s2cid=15764445|issn=0004-637X}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 2×10<sup>12</sup> (2&nbsp;trillion)
| Estimated time by which all objects beyond our Local Group are [[redshift]]ed by a factor of more than 10<sup>53</sup>. Even the highest energy [[gamma ray]]s are stretched so that their wavelength is greater than the physical diameter of the horizon.<ref>{{Cite journal|last1=Krauss|first1=Lawrence M.|last2=Starkman|first2=Glenn D.|date=March 2000|title=Life, The Universe, and Nothing: Life and Death in an Ever-Expanding Universe|journal=The Astrophysical Journal|volume=531|issue=1|pages=22–30|doi=10.1086/308434|arxiv=astro-ph/9902189|bibcode=2000ApJ...531...22K|s2cid=18442980|issn=0004-637X}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 4×10<sup>12</sup> (4&nbsp;trillion)
| Estimated time until the red dwarf star [[Proxima Centauri]], the closest star to the Sun at a distance of 4.25 [[light-year]]s, leaves the main sequence and becomes a white dwarf.<ref>{{cite journal|title=RED Dwarfs and the End of The Main Sequence|author1=Fred C. Adams|author2=Gregory Laughlin|author3=Genevieve J. M. Graves|journal=Revista Mexicana de Astronomía y Astrofísica, Serie de Conferencias|volume=22|pages=46–49|year=2004|url=http://www.astroscu.unam.mx/rmaa/RMxAC..22/PDF/RMxAC..22_adams.pdf|access-date=2020-10-28|archive-date=2019-07-11|archive-url=https://web.archive.org/web/20190711072446/http://www.astroscu.unam.mx/rmaa/RMxAC..22/PDF/RMxAC..22_adams.pdf|url-status=dead}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 10<sup>13</sup> (10 trillion)
| Estimated time when the universe will be the easiest for life as we know it to live in, on average, unless habitability around low-mass stars is suppressed.<ref name=loeb_2016/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 1.2×10<sup>13</sup> (12 trillion)
| Estimated time until the red dwarf [[VB 10]] runs out of hydrogen in its core and becomes a white dwarf. As of 2016, VB 10 was the least massive [[main sequence]] star. It had an estimated mass of 0.075 {{Solar mass}}.<ref name="S&T 22">{{cite journal| title=Why the Smallest Stars Stay Small| journal=Sky & Telescope|date=November 1997| issue=22}}</ref><ref>{{cite journal| journal=Astronomische Nachrichten| volume= 326| issue=10| pages= 913–919| date= 2005| title=M dwarfs: planet formation and long term evolution| first=F. C.|last= Adams| author2= P. Bodenheimer| author3=G. Laughlin|bibcode=2005AN....326..913A|doi=10.1002/asna.200510440}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 3×10<sup>13</sup> (30&nbsp;trillion)
| Estimated time for stars (including the Sun) to undergo a close encounter with another star in local stellar neighborhoods. Whenever two stars (or [[stellar remnants]]) pass close to each other, their planets' orbits can be change, so the planets can be shot out of the star's solar system. On average, the closer a planet's orbit to its parent star, the harder it is for it to be thrown out in this way.<ref name="strip"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 10<sup>14</sup> (100&nbsp;trillion)
| High estimate for the time by which normal [[star formation]] ends in galaxies.<ref name="dying"/> This marks the transition from the [[Future of an expanding universe|Stelliferous Era to the Degenerate Era]]. There will be no more free hydrogen to make any new stars. So all stars that are already there will slowly run out of fuel and die one by one.<ref name="five ages"/> By this time, the universe will also have expanded by a factor of approximately 10<sup>2554</sup>.<ref name=":0"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 1.1–1.2×10<sup>14</sup> (110–120 trillion)
| Time by which all stars in the universe will have run out of fuel (the longest-lived stars, low-mass [[red dwarf]]s, have lifespans of roughly 10–20 trillion years).<ref name="dying"/> After this point, objects that are as big as stars today will be mostly stellar remnants ([[white dwarf]]s, [[neutron star]]s, [[stellar black hole|black holes]]) and [[brown dwarf]]s.

Collisions between brown dwarfs will create a few new red dwarfs: on average, about 100 stars will still be shining in what was once the Milky Way. Collisions between stellar remnants will create occasional supernovae.<ref name="dying"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 10<sup>15</sup> (1 quadrillion)
| Estimated time until stellar close encounters cause all planets in star systems to be thrown away into space.<ref name="dying"/>

By this point, the [[Black dwarf|Sun will have cooled]] to 5 K.<ref name="five degs"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 10<sup>19</sup> to 10<sup>20</sup><br/>(10–100 quintillion)
| Estimated time until 90–99% of brown dwarfs and stellar remnants (including the Sun) are ejected from galaxies. When two objects pass close enough to each other, they exchange orbital energy, with lower-mass objects tending to gain energy. Through repeated encounters, the lower-mass objects can gain enough energy to be thrown away from their galaxy. This process will eventually cause the Milky Way to lose most of its brown dwarfs and stellar remnants.<ref name="dying"/><ref name="five ages pp85–87"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 10<sup>20</sup> (100 quintillion)
| Estimated time until the Earth crashes into with the black dwarf Sun because its orbit will decay from emission of [[Gravitational wave|gravitational radiation]].<ref name="dyson"/> This will only happen if the Earth is not thrown out from its orbit by a stellar encounter or engulfed by the Sun during its red giant phase.<ref name="dyson"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 10<sup>30</sup>
| Estimated time until those stars that are not ejected from galaxies (1–10%) fall into their galaxies' central [[supermassive black hole]]s. By this point, with [[binary star]]s having fallen into each other, and planets into their stars, via emission of gravitational radiation, only solitary objects (stellar remnants, brown dwarfs, ejected planetary-mass objects, black holes) will remain in the universe.<ref name=dying/>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 2×10<sup>36</sup>
| Estimated time for all [[nucleon]]s in the observable universe to decay. This will only happen if the hypothesized [[Proton decay|proton half-life]] takes its smallest possible value (8.2×10<sup>33</sup> years).<ref name="proton"/><ref name="half-life"/><ref name=half-life group=note>Around 264 half-lives. Tyson et al. employ the computation with a different value for half-life.</ref>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 3×10<sup>43</sup>
| Estimated time for all nucleons in the observable universe to decay, if the hypothesized proton half-life takes the largest possible value, 10<sup>41</sup> years,<ref name="dying"/> assuming that the Big Bang was [[inflation (cosmology)|inflationary]] and that the same process that made baryons predominate over anti-baryons in the early Universe makes protons decay.<ref name="half-life"/><ref name=half-life group=note/> By this time, if protons do decay, the [[Future of an expanding universe|Black Hole Era]], in which black holes are the only things left in space, begins.<ref name="five ages"/><ref name="dying"/>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 10<sup>65</sup>
| If [[proton]]s do not decay, this is the estimated time for rigid objects, such as rocks floating in space and planets, will rearrange their atoms and molecules via [[quantum tunneling]]. On this timescale, any body of matter will act as if it were liquid and becomes a smooth sphere.<ref name="dyson"/>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 2×10<sup>66</sup>
| Estimated time until a black hole of 1 solar mass decays into [[subatomic particle]]s due to [[Hawking radiation]].<ref name="Page 1976"/>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 6×10<sup>99</sup>
| Estimated time until the supermassive black hole of [[TON 618]] disappears due to emission of Hawking radiation. As of 2018, TON 618 was the [[List of most massive black holes|largest known]] black hole. It had a mass of 66 billion solar masses,<ref name="Page 1976"/> assuming zero angular momentum (that it does not rotate).
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 1.7×10<sup>106</sup>
| Estimated time until any supermassive black hole with a mass of 20 trillion solar masses decays by Hawking radiation.<ref name="Page 1976"/> This will be the end of the Black Hole Era. After this, if protons do decay, the Universe will enter the [[Dark Era]], in which all physical objects will have decayed in to subatomic particles, gradually becoming the [[heat death of the universe]].<ref name="five ages"/><ref name="dying"/>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
|10<sup>139</sup>
|2018 estimate of Standard Model lifetime before [[False vacuum#Vacuum metastability event|collapse of a false vacuum]]; 95% confidence interval is 10<sup>58</sup> to 10<sup>241</sup> years due in part to uncertainty about the top quark mass.<ref>{{Cite journal|last1=Andreassen|first1=Anders|last2=Frost|first2=William|last3=Schwartz|first3=Matthew D.|date=12 March 2018|title=Scale-invariant instantons and the complete lifetime of the standard model|journal=Physical Review D|volume=97|issue=5|page=056006|doi=10.1103/PhysRevD.97.056006|arxiv=1707.08124|bibcode=2018PhRvD..97e6006A|s2cid=118843387}}</ref>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 10<sup>200</sup>
| Estimated latest time for all nucleons in the observable universe to decay, only if they do not already decay for one of the reasons named above, through higher-order [[Baryon number|baryon non-conservation]] processes, [[virtual black hole]]s, [[sphaleron]]s, or other causes, on time scales of 10<sup>46</sup> to 10<sup>200</sup> years.<ref name="five ages"/>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 10<sup>1100-32000</sup>
| Estimated time for black dwarfs larger than 1.2 times the mass of the Sun to become supernovae because of slow [[silicon]]-[[nickel]]-[[iron]] fusion. The decreasing electron fraction lowers their [[Chandrasekhar limit]], assuming protons do not decay.<ref>{{cite journal|title=Black Dwarf Supernova in the Far Future|author=M. E. Caplan|journal=[[MNRAS]]|number=1–6|date=7 August 2020|volume=497|pages=4357–4362|doi=10.1093/mnras/staa2262|arxiv=2008.02296}}</ref>  
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 10<sup>1500</sup>
| Assuming protons do not decay, the estimated time until all [[baryonic matter]] in stellar-mass objects will have either fused together via [[muon-catalyzed fusion]] to form [[iron-56]] or they will decay from a higher mass element into iron-56 to form an [[iron star]].<ref name="dyson"/>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| <math>10^{10^{26}}</math><ref name="bignumber" group="note"><math>10^{10^{26}}</math> is 1 followed by 10<sup>26</sup> (100 septillion) zeroes</ref><ref name=bignumber2 group=note>Although listed in years for convenience, the numbers beyond this point are so vast that their [[Numerical digit|digits]] would remain unchanged regardless of which conventional units they were listed in, be they [[nanosecond]]s or [[stellar evolution|star lifespans]].</ref>
| Latest possible estimated time until all iron stars collapse via [[quantum tunnelling]] into [[black hole]]s, assuming no [[proton decay]] or [[virtual black holes]].<ref name="dyson"/>

On this vast timescale, even the most stable iron stars will have been destroyed by quantum tunnelling. First, iron stars of sufficient mass (somewhere between 0.2 {{Solar mass}} and the [[Chandrasekhar limit]]<ref>{{cite journal|title=The fate of a neutron star just below the minimum mass: does it explode?|journal=Astronomy and Astrophysics|volume=334|pages=159|author=K. Sumiyoshi, S. Yamada, H. Suzuki, W. Hillebrandt|date=21 July 1997 |arxiv=astro-ph/9707230 |quote=Given this assumption... the minimum possible mass of a neutron star is 0.189|bibcode=1998A&A...334..159S}}</ref>) will collapse into neutron stars. Next, neutron stars and any remaining iron stars heavier than the Chandrasekhar limit will collapse via tunnelling into black holes. Then, each black hole will dissolve into subatomic particles (a process lasting roughly [[googol|10<sup>100</sup>]] years), and the universe will go into the [[Dark Era]].

|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| <math>10^{10^{50}}</math><ref name=prob group=note/><ref name=bignumber2 group=note/><wbr/><ref group="note"><math>10^{10^{50}}</math>is 1 followed by 10<sup>50</sup> (100 quindecillion) zeroes</ref>
| Estimated time for a [[Boltzmann brain]] to appear in the vacuum since there will be less spontaneous [[entropy]].<ref name="linde"/>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| <math>10^{10^{76}}</math><ref name=bignumber2 group=note/>
| High estimate for the time until all iron stars collapse into black holes, assuming no proton decay or virtual black holes,<ref name="dyson"/> which then (on these timescales) instantaneously evaporate into subatomic particles.

This is the latest possible time the Black Hole Era (and subsequent Dark Era) could begin. Beyond this point, it is almost certain that the Universe will not have any baryonic matter and will be an almost pure vacuum (it might also have a [[false vacuum]]) until the [[heat death of the universe]], assuming it does not happen before this.
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| <math>10^{10^{120}}</math><ref name=bignumber2 group=note/>
| Highest estimate for the time it takes for the universe to reach its final energy state, even in the presence of a false vacuum.<ref name="linde"/>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| <math>10^{10^{10^{56}}}</math><ref name=prob group=note/><ref name=bignumber2 group=note/>
| If it is possible, this is when quantum effects will cause a new [[Big Bang]], which will make a new universe according to [[Sean M. Carroll]] and [[Jennifer Chen]]. Around this time, quantum tunnelling in any isolated patch of the now-empty universe could generate new [[cosmic inflation|inflationary events]], resulting in new Big Bangs giving birth to new universes.<ref name="carroll and chen"/><!-- Quote from source: "The important feature of this probability, calculated in the context of a specific model, is not its actual numerical value, but simply the fact that it is nonzero." -->

Because the total number of ways in which all the subatomic particles in the observable universe could be combined is <math>10^{10^{115}}</math>,<ref name="TegmarkPUstaple">{{cite journal | last1 = Tegmark | first1 = M | date = 7 February 2003 | title = Parallel universes. Not just a staple of science fiction, other universes are a direct implication of cosmological observations | bibcode = 2003SciAm.288e..40T | journal = Sci. Am. | volume = 288 | issue = 5| pages = 40–51 | doi=10.1038/scientificamerican0503-40 | pmid=12701329|arxiv = astro-ph/0302131 }}</ref><ref>{{cite journal |author1=Max Tegmark |journal=In "Science and Ultimate Reality: From Quantum to Cosmos", Honoring John Wheeler's 90th Birthday. J. D. Barrow, P.C.W. Davies, & C.L. Harper Eds. |title=Parallel Universes |date= 7 February 2003 |arxiv=astro-ph/0302131 |bibcode = 2003SciAm.288e..40T |doi = 10.1038/scientificamerican0503-40 |pmid=12701329 |volume=288 |issue=5 |pages=40–51}}</ref> a number which, when multiplied by <math>10^{10^{10^{56}}}</math>, disappears into the rounding error. This is also the time it would take for quantum-tunnelled and [[quantum fluctuation]]-generated Big Bang to produce a new universe identical or very similar to our own. This would only happen if every new universe contained at least the same number of subatomic particles and obeyed laws of physics within [[String theory landscape|the landscape]] predicted by [[string theory]].<ref>{{cite journal|author=[[Michael R. Douglas|M. Douglas]]|title=The statistics of string / M theory vacua|journal=JHEP|volume=0305|issue=46|date=21 March 2003|page=046|doi=10.1088/1126-6708/2003/05/046|arxiv=hep-th/0303194|bibcode=2003JHEP...05..046D|s2cid=650509}}</ref><ref>{{cite journal|author1=S. Ashok|author2=M. Douglas|title=Counting flux vacua|journal=JHEP|volume=0401|issue=60|date=2004|page=060|doi=10.1088/1126-6708/2004/01/060|arxiv=hep-th/0307049|bibcode=2004JHEP...01..060A|s2cid=1969475}}</ref>
|}

==Humanity==

{| class="wikitable" style="width: 100%; margin-right: 0;"
|-
! scope="col" | [[File:Key.svg|12px]]
! scope="col" | Years from now
! scope="col" | Event
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|Technology and culture]]
| 10,000
| This could be the longest technological civilization could last, according to [[Frank Drake]]'s original formulation of the [[Drake equation]].<ref>{{cite book|last1=Smith|first1=Cameron|last2=Davies|first2=Evan T.|title=Emigrating Beyond Earth: Human Adaptation and Space Colonization|date=2012|publisher=Springer|page=258}}{{ISBN missing}}</ref>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt=Biology|Biology]]
| 10,000
| If human beings [[panmixia|choose spouses and other sex partners at random]], then [[human genetic variation]] will no longer be related to what part of the planet people are from. The [[effective population size]] will equal the actual population size.<ref>{{cite book|last1=Klein|first1=Jan|last2=Takahata|first2=Naoyuki|title=Where Do We Come From?: The Molecular Evidence for Human Descent|url=https://archive.org/details/wheredowecomefro0000klei|date=2002|publisher=Springer|page=[https://archive.org/details/wheredowecomefro0000klei/page/395 395]|isbn=9783540425649}}{{ISBN missing}}</ref>
|-
| style="background: #e0ffff;" | [[File:Greek lc pi icon.svg|16px|alt=Mathematics|Mathematics]]
| 10,000
|Humanity has a 95% probability of [[Human extinction|being extinct]] by this date, according to [[Brandon Carter]]'s formulation of the controversial [[Doomsday argument]], which argues that half of the humans who will ever have lived have probably already been born.<ref name="brandon"/>
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|technology and culture]]
| 20,000
|According to the [[glottochronology]] linguistic model of [[Morris Swadesh]], future languages should retain just 1 out of 100 "core vocabulary" words on their [[Swadesh list]] compared to that of their current ancestor languages.<ref>{{cite book|last=Greenberg|first=Joseph|title=Language in the Americas|date=1987|publisher=Stanford University Press|pages=341–342}}{{ISBN missing}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 100,000+
| Time required to [[terraforming of Mars|make Mars into a place where people can live]] with an [[oxygen]]-rich breathable atmosphere, using only plants with solar efficiency comparable to those living on Earth.<ref>{{cite journal|last=McKay|first=Christopher P.|author2=Toon, Owen B. |author3=Kasting, James F. |title=Making Mars habitable|journal=Nature|date=8 August 1991|volume=352|issue=6335|pages=489–496|doi=10.1038/352489a0|pmid=11538095|bibcode = 1991Natur.352..489M |s2cid=2815367|url=https://zenodo.org/record/1233115}}</ref>
|-
| [[File:Aiga toiletsq men.svg|16px|alt=Technology and culture|Technology and culture]]
|1 million
| Estimated shortest time by which humanity could colonize our Milky Way galaxy and become capable of [[Kardashev scale|harnessing all the energy of the galaxy]], assuming a velocity of 10% the [[speed of light]].<ref name="typeiii"/>
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt=Biology|Biology]]
| 2 million
| Vertebrate species separated for this long will generally undergo [[allopatric speciation]].<ref>{{cite journal|last=Avise |first=John |authorlink=John Avise |author2=D. Walker |author3=G. C. Johns |title=Speciation durations and Pleistocene effects on vertebrate phylogeography|journal=Philosophical Transactions of the Royal Society B|date=22 September 1998|volume=265|issue=1407|pages=1707–1712|doi=10.1098/rspb.1998.0492 |pmid=9787467 |pmc=1689361}}</ref> Evolutionary biologist [[James W. Valentine]] predicted that if humanity travels to different places in [[space colonization|space]] and then those groups of people stop meeting each other, over this time, they will undergo [[evolutionary radiation]] and become different species with modern humans as their ancestor, with a "diversity of form and adaptation that would astound us."<ref>{{cite book|last=Valentine|first=James W.|authorlink=James W. Valentine|editor1-last=Finney|editor1-first=Ben R.|editor1-link=Ben Finney|editor2-last=Jones|editor2-first=Eric M.|title=Interstellar Migration and the Human Experience|date=1985|publisher=University of California Press|chapter=The Origins of Evolutionary Novelty And Galactic Colonization|page=274}}{{ISBN missing}}</ref> This would be a natural process of isolated populations, so it would happen even if people invent [[Gene therapy|genetic enhancement]] technology.
|-
| style="background: #e0ffff;" | [[File:Greek lc pi icon.svg|16px|alt=Mathematics|Mathematics]]
| 7.8 million
|Humanity has a 95% probability of being extinct by this date, according to [[J. Richard Gott]]'s formulation of the controversial [[Doomsday argument]].<ref>{{Cite journal
 | author = J. Richard Gott, III
 | title = Implications of the Copernican principle for our future prospects
 | journal = [[Nature (journal)|Nature]]
 | volume = 363
 | pages = 315–319
 | year = 1993
 | doi = 10.1038/363315a0
 | issue = 6427
|bibcode = 1993Natur.363..315G | s2cid = 4252750
 }}</ref>
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|Technology and culture]]
| 100 million
| This is the longest technological civilization could last, according to [[Frank Drake]]'s original formulation of the [[Drake equation]].<ref>{{cite book|last1=Bignami|first1=Giovanni F.|last2=Sommariva|first2=Andrea|title=A Scenario for Interstellar Exploration and Its Financing|url=https://archive.org/details/scenarioforinter00bign|url-access=limited|date=2013|publisher=Springer|page=[https://archive.org/details/scenarioforinter00bign/page/n29 23]|bibcode=2013sief.book.....B|isbn=9788847053373}}{{ISBN missing}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 1 billion
| Estimated time for an [[Astronomical engineering|astroengineering]] project that could alter the [[Earth's orbit]], so that the Earth's climate would stay the same even though the Sun will become brighter.  People could do this by using asteroids with enough [[gravity assist|gravity]] to pull on the Earth.<ref>{{cite journal | first=D. G. | last=Korycansky |author2=Laughlin, Gregory|author3= Adams, Fred C. | date=2001 |
title=Astronomical engineering: a strategy for modifying planetary orbits | url=https://archive.org/details/sim_astrophysics-and-space-science_2001-03_275_4/page/349 | doi=10.1023/A:1002790227314 | journal=Astrophysics and Space Science | id=Astrophys.Space Sci.275:349-366,2001 | volume=275 | issue=4 | pages=349–366 | hdl=2027.42/41972 | bibcode=2001Ap&SS.275..349K | arxiv=astro-ph/0102126 | s2cid=5550304 }}</ref><ref>{{cite journal|last=Korycansky|first=D. G.|title=Astroengineering, or how to save the Earth in only one billion years|journal=Revista Mexicana de Astronomía y Astrofísica|date=2004|volume=22|pages=117–120|url=http://www.astroscu.unam.mx/rmaa/RMxAC..22/PDF/RMxAC..22_korycansky.pdf|bibcode=2004RMxAC..22..117K|access-date=2020-10-28|archive-date=2015-09-23|archive-url=https://web.archive.org/web/20150923175649/http://www.astroscu.unam.mx/rmaa/RMxAC..22/PDF/RMxAC..22_korycansky.pdf|url-status=dead}}</ref>

|}

== Spacecraft and space exploration ==
As of 2020, five [[spacecraft|machines that travel through outer space]] are moving toward the edge of the solar system: ''[[Voyager 1]]'', ''[[Voyager 2]]'', ''[[Pioneer 10]]'', ''[[Pioneer 11]]'' and ''[[New Horizons]]''. They will travel into [[interstellar medium|interstellar space]]. So long as they do not crash into anything, these machines should persist indefinitely.<ref name="time"/>

{| class="wikitable" style="width: 100%; margin-right: 0;"
|-
! scope="col" | [[File:Key.svg|12px]]
! scope="col" | Years from now
! scope="col" | Event
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
|4000 
|The [[SNAP-10A]] nuclear satellite will return to the surface.  It was launched in 1965 and its orbit is {{cvt|700|km}} high off the surface of the planet.<ref>{{cite book | last = Staub | first = D.W. | title = SNAP 10 Summary Report | publisher = Atomics International Division of North American Aviation, Inc., Canoga Park, California | date = 25 March 1967 | id = NAA-SR-12073}}</ref><ref>{{cite news |url=http://nla.gov.au/nla.news-article110889894 |title=U.S. ADMISSION : Satellite mishap released rays |newspaper=[[The Canberra Times]] |volume=52 |issue=15,547 |location=Australian Capital Territory, Australia |date=30 March 1978 |accessdate=12 August 2017 |page=5 |via=National Library of Australia}}, ''...Launched in 1965 and carrying about 4.5 kilograms of uranium 235, Snap 10A is in a 1,000-year orbit....''</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 16,900
| ''[[Voyager 1]]'' will pass within 3.5 [[light-year]]s of [[Proxima Centauri]].<ref name=lavender>{{Cite journal|title = Future stellar flybys of the Voyager and Pioneer spacecraft|journal = Research Notes of the American Astronomical Society|volume= 3|pages = 59|number=59|doi=10.3847/2515-5172/ab158e|date = 3 April 2019|author = Coryn A.L. Bailer-Jones, Davide Farnocchia|arxiv = 1912.03503|bibcode = 2019RNAAS...3...59B|s2cid = 134524048 | doi-access=free }}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 18,500
| ''[[Pioneer 11]]'' will pass within 3.4 light-years of [[Alpha Centauri]].<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 20,300
| ''[[Voyager 2]]'' will pass within 2.9 light-years of Alpha Centauri.<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 25,000
| The [[Arecibo message]] is a collection of radio data. It was transmitted on November 16, 1974. It will reach the distance of its destination, the [[globular cluster]] [[Messier 13]].<ref name="glob"/> This is the only [[List of interstellar radio messages|interstellar radio message]] sent so far away. There will be a 24-light-year shift in the cluster's position in the galaxy during the time it takes the message to reach it. However, because the cluster is 168 light-years in diameter, the message will still reach its destination.<ref>{{cite web|title=In regard to the email from|publisher=Science 2.0|author=Dave Deamer|url=http://www.science20.com/comments/28100/In_regard_to_the_email_from|accessdate=14 November 2014|url-status=dead|archiveurl=https://web.archive.org/web/20150924095532/http://www.science20.com/comments/28100/In_regard_to_the_email_from|archivedate=24 September 2015}}</ref> Any reply will take at least another 25,000 years to reach it, assuming [[faster-than-light communication]] is impossible.
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 33,800
| ''[[Pioneer 10]]'' will pass within 3.4 light-years of [[Ross 248]].<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 34,400
| ''[[Pioneer 10]]'' will pass within 3.4 light-years of Alpha Centauri.<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 42,200
| ''[[Voyager 2]]'' will pass within 1.7 light-years of Ross 248.<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 44,100
| ''[[Voyager 1]]'' will pass within 1.8 light-years of [[Gliese 445]].<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 46,600
| ''[[Pioneer 11]]'' will pass within 1.9 light-years of Gliese 445.<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 50,000
| The ''[[KEO]]'' space time capsule, if it is launched, will reenter Earth's atmosphere.<ref name="keo1"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 90,300
| ''[[Pioneer 10]]'' will pass within 0.76 light-years of [[HIP 117795]].<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 306,100
| ''[[Voyager 1]]'' will pass within 1 light-year of [[TYC 3135-52-1]].<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 492,300
| ''[[Voyager 1]]'' will pass within 1.3 light-years of [[HD 28343]].<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 800,000–8 million
| This is the earliest that the  [[Pioneer plaque|Pioneer 10 plaque]] will wear out: the etching on it will become invisible because of interstellar erosion.<ref>{{cite web|last=Lasher |first=Lawrence |title=Pioneer Mission Status |url=http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PNStat.html |publisher=NASA|url-status=dead |archiveurl=https://web.archive.org/web/20000408152959/http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PNStat.html |archivedate=8 April 2000 |quote=[Pioneer's speed is] about 12&nbsp;km/s... [the plate etching] should survive recognizable at least to a distance ≈10 parsecs, and most probably to 100 parsecs.}}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 1.2 million
| ''[[Pioneer 11]]'' will come within 3 light-years of [[Delta Scuti]].<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 1.3 million
| ''[[Pioneer 10]]'' will come within 1.5 light-years of [[HD 52456]].<ref name=lavender/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 2 million
| ''[[Pioneer 10]]'' will pass near the bright star [[Aldebaran]].<ref name="Pioneer Ames"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 4 million
| ''[[Pioneer 11]]'' will pass near one of the stars in the constellation [[Aquila (constellation)|Aquila]].<ref name="Pioneer Ames"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 8 million
| The orbits of the ''[[LAGEOS]]'' satellites will decay, and they will re-enter Earth's atmosphere. Any humans still alive at the time will see the messages left by the humans who launched LAGEOS.<ref name="lageos"/>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 1 billion
| By this time the two [[Voyager Golden Record]]s will wear out until no one can read them any more.<ref>{{cite AV media |people=Jad Abumrad and Robert Krulwich |date=12 February 2010 |title= Carl Sagan And Ann Druyan's Ultimate Mix Tape |url=https://www.npr.org/2010/02/12/123534818/carl-sagan-and-ann-druyans-ultimate-mix-tape |medium=Radio |publisher=National Public Radio }}</ref>
|-
| style="background: lavender;" | [[File:Five Pointed Star Solid.svg|16px|alt=Astronomy and astrophysics|Astronomy and astrophysics]]
| 10<sup>20</sup> (100 quintillion)
| Estimated timescale for the Pioneer and Voyager spacecraft to collide with a star (or ruins of a star).<ref name=lavender/>
|}

==Technological projects and time capsules==
A [[time capsule]] is a box or other container that is buried or hidden on purpose and scheduled to be opened many years later.  People place things inside the time capsule so people in the future will find them.  For example, someone might place a game, tool, toy, journal, magazine or book inside a time capsule so people in the future would see how the people who buried the time capsule lived, played and worked and what they liked to read.

{| class="wikitable" style="width: 100%; margin-right: 0;"
|-
! scope="col" | [[File:Key.svg|12px]]
! scope="col" | Date or years from now
! scope="col" | Event
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|Technology and culture]]
|3015 CE
|In 2015, [[Jonathon Keats]] put a camera in the [[ASU Art Museum]] and set it to finish its [[exposure time]] in 3015.  Keats was trying to make history's slowest photograph.<ref>{{cite web |title=This Camera Will Capture a 1,000-Year Exposure That Ends in 3015 for History's Slowest Photo |date=5 March 2015 |url=http://petapixel.com/2015/03/05/this-camera-will-capture-a-1000-year-exposure-that-ends-in-3015-for-historys-slowest-photo/ |publisher=PetaPixel |accessdate=2015-12-14}}</ref>
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|Technology and culture]]
| 10,000
| Planned lifespan of the [[Long Now Foundation]]'s several ongoing projects, including a 10,000-year clock known as the [[Clock of the Long Now]], the [[Rosetta Project]], and the [[Long Now Foundation|Long Bet Project]].<ref name="longnow"/>

Estimated lifespan of the [[HD-Rosetta]] analog disc, an [[Focused ion beam|ion beam-etched]] writing medium on nickel plate, a technology developed at [[Los Alamos National Laboratory]] and later commercialized. (The Rosetta Project uses this technology, named after the [[Rosetta Stone]]).
|-
| style="background: #CEFF00;" | [[File:Butterfly icon (Noun Project).svg|16px|alt=Biology|Biology]]
| 10,000
| Projected lifespan of Norway's [[Svalbard Global Seed Vault]].  The seed vault stores seeds from important plants so humans can bring them back if they become extinct in the rest of the world.<ref>{{cite news|title=A Visit to the Doomsday Vault|url=https://www.cbsnews.com/news/a-visit-to-the-doomsday-vault/|date=20 March 2008|publisher=CBS News}}</ref>
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|technology and culture]]
| 1 million
| Estimated lifespan of [[Memory of Mankind]] (MOM) [[self storage]]-style repository in [[Hallstatt]] salt mine in Austria, which stores information on [[Clay tablet|inscribed tablets]] of [[stoneware]].<ref>{{cite web | title =Memory of Mankind | url = https://www.memory-of-mankind.com/ | accessdate = 4 March 2019}}</ref>
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|technology and culture]]
| 1 million
| Planned lifespan of the Human Document Project being developed at the [[University of Twente]] in the Netherlands.<ref>{{cite web|title=Human Document Project 2014|url=http://hudoc2014.manucodiata.org/|access-date=2020-10-28|archive-date=2014-05-19|archive-url=https://web.archive.org/web/20140519094549/http://hudoc2014.manucodiata.org/|url-status=dead}}</ref>
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|technology and culture]]
| 292 million
| Numeric overflow in system time for [[Java (programming language)|Java]] computer programs.<ref>{{cite web|title=When will System.currentTimeMillis() overflow?|url=https://stackoverflow.com/a/2978462 |publisher=[[Stack Overflow]]}}</ref>
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|Technology and culture]]
| 1 billion
| Estimated lifespan of "[[Molecular shuttle|Nanoshuttle]] memory device" using an [[iron nanoparticle]] moved as a [[molecular switch]] through a [[carbon nanotube]], a technology developed at the [[University of California, Berkeley|University of California at Berkeley]].<ref>{{cite journal|last=Begtrup |first=G. E. |display-authors=4 |author2=Gannett, W. |author3=Yuzvinsky, T. D. |author4=Crespi, V. H. |author5=Zettl, A. |title=Nanoscale Reversible Mass Transport for Archival Memory |journal=Nano Letters |date=13 May 2009 |volume=9 |issue=5 |pages=1835–1838 |doi=10.1021/nl803800c |url=http://www.physics.berkeley.edu/research/zettl/pdf/363.NanoLet.9-Begtrup.pdf |bibcode=2009NanoL...9.1835B |pmid=19400579 |url-status=dead |archiveurl=https://web.archive.org/web/20100622232231/http://www.physics.berkeley.edu/research/zettl/pdf/363.NanoLet.9-Begtrup.pdf |archivedate=22 June 2010 |citeseerx=10.1.1.534.8855 }}</ref>
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|technology and culture]]
| more than 13 billion
| Estimated lifespan of "[[5D optical data storage|Superman memory crystal]]" data storage using [[Mode-locking|femtosecond laser]]-etched [[nanostructure]]s in glass.<ref>{{cite journal|last1=Zhang|first1=J. |last2=Gecevičius|first2=M. |last3=Beresna|first3=M. |last4=Kazansky|first4=P. G. |title=Seemingly unlimited lifetime data storage in nanostructured glass|url=https://www.researchgate.net/publication/260004721|journal=Phys. Rev. Lett.|volume=112|issue=3 |page=033901|doi=10.1103/PhysRevLett.112.033901|pmid=24484138 |date=2014|bibcode = 2014PhRvL.112c3901Z |s2cid=27040597 }}</ref><ref>{{cite journal|last1=Zhang|first1=J.|last2=Gecevičius|first2=M.|last3=Beresna|first3=M.|last4=Kazansky|first4=P. G.|title=5D Data Storage by Ultrafast Laser Nanostructuring in Glass|journal=CLEO: Science and Innovations|date=June 2013|pages=CTh5D–9|url=http://www.orc.soton.ac.uk/fileadmin/downloads/5D_Data_Storage_by_Ultrafast_Laser_Nanostructuring_in_Glass.pdf|url-status=dead|archiveurl=https://web.archive.org/web/20140906152109/http://www.orc.soton.ac.uk/fileadmin/downloads/5D_Data_Storage_by_Ultrafast_Laser_Nanostructuring_in_Glass.pdf|archivedate=6 September 2014|df=dmy-all}}</ref>
|-
| [[File:Aiga toiletsq men.svg|16px|alt=technology and culture|technology and culture]]
| 292 billion
| Numeric overflow in system time for 64-bit [[Unix]] systems.<ref>{{cite web |title=Date/Time Conversion Contract Language |url=https://its.ny.gov/sites/default/files/documents/nys-p98-003_date_time_conversion_contract_language_1.pdf |publisher=Office of Information Technology Services, [[New York (state)]] |accessdate=16 October 2020 |date=19 May 2019 |archive-date=30 April 2021 |archive-url=https://web.archive.org/web/20210430113627/https://its.ny.gov/sites/default/files/documents/nys-p98-003_date_time_conversion_contract_language_1.pdf |url-status=dead }}</ref>
|}

==Human constructs==
{| class="wikitable" style="width: 100%; margin-right: 0;"
|-
! scope="col" | [[File:Key.svg|12px]]
! scope="col" | Years from now
! scope="col" | Event
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 50,000
| This is about how long [[tetrafluoromethane]] lasts in the atmosphere.  Tetrafluoromethane is the [[greenhouse gas]] that lasts the longest.<ref>{{cite web|title=Tetrafluoromethane|url=http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+1327|website=[[Hazardous Substances Data Bank|Toxicology Data Network (TOXNET)]]|publisher=United States National Library of Medicine|accessdate=4 September 2014}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 1 million
| Current [[glass]] objects in the environment will decompose.<ref>{{cite web|title=Time it takes for garbage to decompose in the environment|url=http://des.nh.gov/organization/divisions/water/wmb/coastal/trash/documents/marine_debris.pdf|publisher=New Hampshire Department of Environmental Services|access-date=23 May 2014|archive-url=https://web.archive.org/web/20140609083232/http://des.nh.gov/organization/divisions/water/wmb/coastal/trash/documents/marine_debris.pdf|archive-date=9 June 2014|url-status=dead|df=dmy-all}}</ref>

[[:Category:Granite sculptures|Outdoor statues made out of hard granite]] will have worn away by one meter.  This assumes the statues are in moderate climates and rate of 1 [[Bubnoff unit]] (1&nbsp;mm in 1,000 years, or ≈1 inch in 25,000 years).<ref>{{cite book|last=Lyle|first=Paul|title=Between Rocks And Hard Places: Discovering Ireland's Northern Landscapes|date=2010|publisher=Geological Survey of Northern Ireland}}{{ISBN missing}}</ref>

If human beings stop taking care of it, the [[Great Pyramid of Giza]] will wear away until it does not look like a pyramid any more.<ref>{{cite book |last=Weisman |first=Alan |authorlink=Alan Weisman |title=The World Without Us |url=https://archive.org/details/worldwithoutus00weis |url-access=limited |pages= [https://archive.org/details/worldwithoutus00weis/page/171 171]–172 |date=10 July 2007 |publisher=Thomas Dunne Books/St. Martin's Press |location=New York |isbn=978-0-312-34729-1 |oclc=122261590}}</ref>

The footprints that [[Neil Armstrong]] and [[List of Apollo astronauts#Apollo astronauts who walked on the Moon|other Apollo astronauts]] left on the [[Moon]] will be erased by [[space weathering]].<ref>{{cite web|title=Apollo 11 – First Footprint on the Moon|url=http://www.nasa.gov/audience/forstudents/k-4/home/F_Apollo_11.html|website=Student Features|publisher=NASA|access-date=2020-10-28|archive-date=2021-04-03|archive-url=https://web.archive.org/web/20210403084654/https://www.nasa.gov/audience/forstudents/k-4/home/F_Apollo_11.html|url-status=dead}}</ref><ref>{{cite book|last=Meadows|first=A. J.|title=The Future of the Universe|url=https://archive.org/details/futureuniverse00mead_163|url-access=limited|date=2007|publisher=Springer|pages=[https://archive.org/details/futureuniverse00mead_163/page/n87 81]–83|isbn=9781852339463}}{{ISBN missing}}</ref> (The Moon [[atmosphere of the Moon|does not have wind and rain]] the way Earth does, so erosion takes longer.)
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 7.2 million
|If human beings stop taking care of it, [[Mount Rushmore]] will wear away until the faces of the presidents won't show any more.<ref>{{cite book |last=Weisman |first=Alan |authorlink=Alan Weisman |title=The World Without Us |url=https://archive.org/details/worldwithoutus00weis |url-access=limited |page= [https://archive.org/details/worldwithoutus00weis/page/182 182] |date=10 July 2007 |publisher=Thomas Dunne Books/St. Martin's Press |location=New York |isbn=978-0-312-34729-1 |oclc=122261590}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 100 million
| Future archaeologists should be able to identify an "Urban [[Stratum]]" of fossilized [[port|great coastal cities]], mostly by looking at underground things, such as [[Foundation (engineering)|building foundations]] and [[utility tunnel]]s.<ref>{{cite book |last=Zalasiewicz |first=Jan |title=The Earth After Us: What legacy will humans leave in the rocks? |date=25 September 2008 |publisher=Oxford University Press}}, [http://www.stanford.edu/dept/archaeology/cgi-bin/archaeolog/?p=239 Review in Stanford Archaeolog] {{Webarchive|url=https://web.archive.org/web/20140513011343/http://www.stanford.edu/dept/archaeology/cgi-bin/archaeolog/?p=239 |date=2014-05-13 }}</ref>
|}

==Nuclear power==
{| class="wikitable" style="width: 100%; margin-right: 0;"
|-
! scope="col" | [[File:Key.svg|12px]]
! scope="col" | Years from now
! scope="col" | Event
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 10,000
|The [[Waste Isolation Pilot Plant]], which is where dangerous, radioactive waste from nuclear weapons waste is stored, is planned to be protected until this time.  The people who built it wondered what would happen if civilization fell apart and people forgot not to enter the Waste Isolation Pilot Plant or thought the walls and doors meant there was treasure hidden there.  It has a "Permanent Marker" system designed to warn visitors that the place is dangerous.  It is marked in many languages (the [[Official languages of the United Nations|six UN languages]] and [[Navajo language|Navajo]]) and in [[pictogram]]s.<ref>{{cite web|title=Permanent Markers Implementation Plan|url=http://www.wipp.energy.gov/picsprog/test1/Permanent_Markers_Implementation_Plan_rev1.pdf|publisher=[[United States Department of Energy]]|archiveurl=https://web.archive.org/web/20060928144722/http://www.wipp.energy.gov/PICsProg/Test1/Permanent_Markers_Implementation_Plan_rev1.pdf|archivedate=28 September 2006|url-status=dead|date=30 August 2004|df=dmy-all}}</ref> The [[Human Interference Task Force]] developed theories that the United States government could use to communicate with people of the future for other nuclear problems.
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 24,000
|The [[Chernobyl Exclusion Zone]], the {{convert|2600|km2||adj=mid}} area of [[Ukraine]] and [[Belarus]] that people had to leave after [[Chernobyl disaster|Chernobyl nuclear power plant]] blew up in 1986, will return to normal levels of radiation.<ref name=TimeDisaster>{{cite book|title=Time: Disasters that Shook the World|url=https://archive.org/details/timeforkidsbigbo0000unse_b1k6|publisher=Time Home Entertainment|location=New York City|year=2012|isbn=978-1-60320-247-3}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 30,000
| If people keep using electricity as much as they did in 2009, then the amount of fission-based [[breeder reactor]] reserves will run out then.  This assumes no [[List of countries by uranium reserves|new sources]] of fuel are found.<ref name="Fetter">{{cite news|last=Fetter|first=Steve|title=How long will the world's uranium supplies last?|url=http://www.scientificamerican.com/article/how-long-will-global-uranium-deposits-last/|date=March 2009}}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 60,000
| The amount of fuel for fission-based [[light-water reactor]]s will run out if humans manage to collect all the [[uranium]] from seawater, assuming people use as much power as they did in 2009 every year.<ref name="Fetter"/>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 211,000
| [[Half-life]] of [[technetium-99]], the most important [[long-lived fission product]] in nuclear waste from uranium.
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 250,000
| This is the soonest possible time the spent [[plutonium]] in the New Mexico [[Waste Isolation Pilot Plant]] will stop being lethal to humans.<ref>{{cite web |first=David |last=Biello |url=https://www.scientificamerican.com/article/nuclear-waste-lethal-trash-or-renewable-energy-source/|publisher=Scientific American|title=Spent Nuclear Fuel: A Trash Heap Deadly for 250,000 Years or a Renewable Energy Source?|date=28 January 2009}}</ref>
|-
| style="background: #FFE4E1;" | [[File:Psi (greek letter).svg|16px|alt=Particle physics|Particle physics]]
| 15.7 million
| [[Half-life]] of [[iodine-129]], the most durable [[long-lived fission product]] in [[Radioactive waste|nuclear waste]] from uranium.
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 60 million
| If humans manage to collect all the [[lithium]] from seawater, this is when fuel for [[fusion power]] reactors will run out, assuming people use as much power as they did in 1995.<ref name="Ongena 3–14">{{cite journal |last=Ongena |first=J |author2=G. Van Oost |title=Energy for future centuries – Will fusion be an inexhaustible, safe and clean energy source? |journal=Fusion Science and Technology |volume=45 |series=2004 |issue=2T |pages=3–14 |url=http://www.euro-fusionscipub.org/wp-content/uploads/2014/11/EFDR00001.pdf |doi=10.13182/FST04-A464 |year=2004 |s2cid=15368449 |access-date=2020-10-28 |archive-date=2016-08-19 |archive-url=https://web.archive.org/web/20160819140008/http://www.euro-fusionscipub.org/wp-content/uploads/2014/11/EFDR00001.pdf |url-status=dead }}</ref>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 5 billion
| If people manage to collect all the [[uranium]] from seawater, this is when the fuel for fission-based [[breeder reactor]]s will run out, assuming people use as much energy as they did in 1983.<ref name="Cohen"/>
|-
| style="background: #f0dc82;" | [[File:Noun project 528.svg|16px|alt=Geology and planetary science|Geology and planetary science]]
| 150 billion
| If people manage to collect all the [[deuterium]] from seawater, this is when the fuel for [[fusion power]] reactors will run out, assuming people use as much energy as they did in 1995.<ref name="Ongena 3–14"/>
|-
|}

==Related pages==
{{Div col}}
* [[Orders of magnitude (time)]]
* [[Ultimate fate of the universe]]
{{div col end}}

==Notes==
{{reflist|group=note}}

==References==
{{reflist|25em| refs =

<ref name="Nave">
{{cite web | title = Second Law of Thermodynamics | last = Nave | first = C.R. | url = http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/seclaw.html | publisher = [[Georgia State University]] | accessdate =3 December 2011
}}
</ref>

<ref name="five ages">
{{cite book | last1 = Adams | first1 = Fred | last2 = Laughlin | first2 = Greg | date = 1999 | title = The Five Ages of the Universe | url = https://archive.org/details/fiveagesofuniver0000adam | publisher = The Free Press | location = New York | isbn = 978-0684854229
}}
</ref>

<ref name="carroll and chen">
{{cite arXiv | title = Spontaneous Inflation and the Origin of the Arrow of Time | author = Carroll, Sean M. | author2 = Chen, Jennifer | date = 27 October 2004 | eprint = hep-th/0410270 }}
</ref>

<ref name="dying">
{{cite journal | title = A dying universe: the long-term fate and evolution of astrophysical objects | last = Adams | first = Fred C.|author2=Laughlin, Gregory | journal = Reviews of Modern Physics | volume = 69 | issue = 2 | year = 1997 | pages = 337–372 | bibcode = 1997RvMP...69..337A | doi = 10.1103/RevModPhys.69.337 | arxiv = astro-ph/9701131
| s2cid = 12173790 }}
</ref>

<ref name="linde">
{{cite journal | title = Sinks in the Landscape, Boltzmann Brains and the Cosmological Constant Problem | author = Linde, Andrei. | journal = Journal of Cosmology and Astroparticle Physics | year = 2007 | doi = 10.1088/1475-7516/2007/01/022 | volume = 2007 | issue = 1 | page = 022 | arxiv = hep-th/0611043 | bibcode = 2007JCAP...01..022L
| citeseerx = 10.1.1.266.8334 | s2cid = 16984680 }}
</ref>

<ref name="Matthews1993">
{{cite journal | journal = [[Quarterly Journal of the Royal Astronomical Society]]
| last = Matthews | first = R. A. J. | title = The Close Approach of Stars in the Solar Neighborhood
| volume = 35 | issue = 1 | page = 1 | date = Spring 1994
| bibcode = 1994QJRAS..35....1M
}}
</ref>

<ref name="Berger2002">
{{cite journal | author = Berger, A | author2 = Loutre, MF | s2cid = 128923481 | name-list-style = amp | title = Climate: an exceptionally long interglacial ahead? | journal = Science | volume = 297 | issue = 5585 | date = 2002 | pages = 1287–1288 | doi = 10.1126/science.1076120|pmid=12193773
}}
</ref>

<ref name="Niagara Parks">
{{cite web
 |title=Niagara Falls Geology Facts & Figures
 |url=http://www.niagaraparks.com/media/geology-facts-figures.html
 |publisher=[[Niagara Parks]]
 |accessdate=29 April 2011
 |url-status=dead
 |archiveurl=https://web.archive.org/web/20110719093559/http://www.niagaraparks.com/media/geology-facts-figures.html
 |archivedate=19 July 2011
}}
</ref>

<ref name="arxiv1106_3141">
{{Cite journal| last1 = Finkleman | first1 = David | last2 = Allen | first2 = Steve | last3 = Seago | first3 = John | last4 = Seaman | first4 = Rob | last5 = Seidelmann | first5 = P. Kenneth | title = The Future of Time: UTC and the Leap Second | journal = American Scientist, July–August , V N4 P312 | volume = 2011 | issue = 99 |date = June 2011 | arxiv = 1106.3141 | bibcode = 2011arXiv1106.3141F }}
</ref>

<ref name="Tapping 2005">
{{cite web | title = The Unfixed Stars | last = Tapping | first = Ken | publisher = [[National Research Council Canada]] | url = http://www.nrc-cnrc.gc.ca/eng/education/astronomy/tapping/2005/2005-08-31.html | date = 2005 | accessdate = 29 December 2010 | url-status = dead | archiveurl = https://web.archive.org/web/20110708075519/http://www.nrc-cnrc.gc.ca/eng/education/astronomy/tapping/2005/2005-08-31.html | archivedate = 8 July 2011 | df = dmy-all }}
</ref>

<ref name="Monnier Tuthill Lopez 1999">
{{cite journal | title = The Last Gasps of VY Canis Majoris: Aperture Synthesis and Adaptive Optics Imagery | last1 = Monnier | first1 = J. D. | last2 = Tuthill | first2 = P. | last3 = Lopez | first3 = GB | display-authors = 3 | date = 1999 | last4 = Cruzalebes | first4 = P. | last5 = Danchi | first5 = W. C. | last6 = Haniff | first6 = C. A. | journal = [[The Astrophysical Journal]] | volume = 512 | issue = 1 | pages = 351–361 | doi = 10.1086/306761 | bibcode = 1999ApJ...512..351M | arxiv = astro-ph/9810024
| s2cid = 16672180 }}
</ref>

<ref name="havo">
{{cite web | title = Frequently Asked Questions | publisher = Hawai'i Volcanoes National Park | date = 2011 | url = http://www.nps.gov/havo/faqs.htm | accessdate =22 October 2011
}}
</ref>

<ref name="Bostrom 2002">
{{cite journal | last = Bostrom | first = Nick | authorlink = Nick Bostrom | date = March 2002 | title = Existential Risks: Analyzing Human Extinction Scenarios and Related Hazards | journal = Journal of Evolution and Technology | volume = 9 | issue = 1 | url = http://www.nickbostrom.com/existential/risks.html|accessdate=10 September 2012
}}
</ref>

<ref name="betel">
{{cite web
 |title=Betelgeuse will explode someday
 |publisher=EarthSky Communications, Inc
 |author=Sessions, Larry
 |date =29 July 2009
 |url=http://earthsky.org/brightest-stars/betelgeuse-will-explode-someday
 |accessdate=16 November 2010}}
</ref>

<ref name="gliese">
{{cite journal |author=Filip Berski and Piotr A. Dybczyński
 | date= 25 October 2016| title = Gliese 710 will pass the Sun even closer | journal = [[Astronomy and Astrophysics]] | volume = 595 | issue = L10| page= L10| doi = 10.1051/0004-6361/201629835 | bibcode=2016A&A...595L..10B| doi-access = free}}</ref>

<ref name="Bills">{{cite journal|last=Bills|first=Bruce G.|author2=Gregory A. Neumann|author3=David E. Smith|author4=Maria T. Zuber|date=2005|title=Improved estimate of tidal dissipation within Mars from MOLA observations of the shadow of Phobos|journal=Journal of Geophysical Research|volume=110|issue=E07004|pages=E07004|url=http://www-geodyn.mit.edu/bills_phobos05.pdf|doi=10.1029/2004je002376|bibcode=2005JGRE..110.7004B|access-date=16 September 2015|archive-url=https://web.archive.org/web/20170525191706/http://www-geodyn.mit.edu/bills_phobos05.pdf|archive-date=25 May 2017|url-status=dead}}</ref>

<ref name="rift">{{cite web | title = Birth of an Ocean: The Evolution of Ethiopia's Afar Depression | last = Haddok | first = Eitan | date = 29 September 2008 | publisher = [[Scientific American]] | url = http://www.scientificamerican.com/article.cfm?id=birth-of-an-ocean | accessdate = 27 December 2010 | archive-date = 24 December 2013 | archive-url = https://web.archive.org/web/20131224105641/http://www.scientificamerican.com/article.cfm?id=birth-of-an-ocean | url-status = dead }}</ref>

<ref name="trench">
{{cite book | title = Essentials of Oceanography | url = https://archive.org/details/essentialsofocea05edgarr | last = Garrison | first = Tom |edition=5 | page = [https://archive.org/details/essentialsofocea05edgarr/page/62 62] | publisher = Brooks/Cole | date = 2009}}{{ISBN missing}}
</ref>

<ref name="medi">{{cite web | title = Continents in Collision: Pangea Ultima | publisher = [[NASA]] | date = 2000 | url = https://science.nasa.gov/science-news/science-at-nasa/2000/ast06oct_1/ | accessdate = 29 December 2010 | archive-date = 21 August 2012 | archive-url = https://web.archive.org/web/20120821173013/http://science.nasa.gov/science-news/science-at-nasa/2000/ast06oct_1/ | url-status = dead }}</ref>

<ref name="kpg1">
{{cite web | title = Meteorites, Impacts, and Mass Extinction | last = Nelson | first = Stephen A. | publisher = [[Tulane University]] | url = http://www.tulane.edu/~sanelson/geol204/impacts.htm | accessdate =13 January 2011
}}
</ref>

<ref name="galyear">
{{cite web | title = Period of the Sun's Orbit Around the Galaxy (Cosmic Year) | first = Stacy | last = Leong | url = http://hypertextbook.com/facts/2002/StacyLeong.shtml | date = 2002 | website = The Physics Factbook | accessdate =2 April 2007
}}
</ref>

<ref name="scotese">
{{cite web | url = http://www.scotese.com/newpage11.htm| last = Scotese | first = Christopher R. | title = Pangea Ultima will form 250 million years in the Future | website = Paleomap Project | accessdate =13 March 2006
}}
</ref>

<ref name="Williams Nield 2007">
{{cite news
 |last1=Williams
 |first1=Caroline
 |last2=Nield
 |first2=Ted
 |title=Pangaea, the comeback
 |work=New Scientist
 |date=20 October 2007
 |url=http://www.science.org.au/nova/newscientist/104ns_011.htm
 |accessdate=2 January 2014
 |url-status=dead
 |archiveurl=https://web.archive.org/web/20080413162401/http://www.science.org.au/nova/newscientist/104ns_011.htm
 |archivedate=13 April 2008
}}
</ref>

<ref name="Heath Doyle 2009">
{{cite arXiv | last1 = Heath | first1 = Martin J. | last2 = Doyle | first2 = Laurance R. | title = Circumstellar Habitable Zones to Ecodynamic Domains: A Preliminary Review and Suggested Future Directions | eprint=0912.2482 | date = 2009
| class = astro-ph.EP }}
</ref>

<ref name="600mil">
{{cite web
 |url=http://sunearthday.nasa.gov/2006/faq.php
 |title=Questions Frequently Asked by the Public About Eclipses
 |publisher=[[NASA]]
 |accessdate=7 March 2010
 |url-status=live
 |archiveurl=https://web.archive.org/web/20100312030853/http://sunearthday.nasa.gov/2006/faq.php
 |archivedate=12 March 2010
}}
</ref>

<ref name="bd2_6_1665">
{{cite journal | last1 = Franck | first1 = S. | last2 = Bounama | first2 = C. | last3 = Von Bloh | first3 = W. | title = Causes and timing of future biosphere extinction | journal = Biogeosciences Discussions | volume = 2 | issue = 6 | pages = 1665–1679 | date= November 2005 | bibcode = 2006BGeo....3...85F | doi = 10.5194/bgd-2-1665-2005
| s2cid = 3619702 | url = https://hal.archives-ouvertes.fr/hal-00297823/file/bgd-2-1665-2005.pdf | doi-access = free }}
</ref>

<ref name="mnras386_1">
{{cite journal | last1 = Schröder | first1 = K.-P. | last2 = Connon Smith | first2 = Robert | title = Distant future of the Sun and Earth revisited | journal = [[Monthly Notices of the Royal Astronomical Society]] | volume = 386 | issue = 1 | date = 1 May 2008 | pages = 155–163 | doi = 10.1111/j.1365-2966.2008.13022.x | bibcode = 2008MNRAS.386..155S
|arxiv = 0801.4031 | s2cid = 10073988 }}
</ref>

<ref name="abode">
{{cite book | last1 = Brownlee | first1 = Donald E. | date = 2010 | chapter = Planetary habitability on astronomical time scales | title = Heliophysics: Evolving Solar Activity and the Climates of Space and Earth | editor1-first = Carolus J. | editor1-last = Schrijver | editor2-first = George L. |editor2-link=George Siscoe | editor2-last = Siscoe |chapter-url = https://books.google.com/books?id=M8NwTYEl0ngC&pg=PA79 | publisher = Cambridge University Press | isbn = 978-0521112949
}}
</ref>

<ref name="mars">
{{cite book | title = Mars: A Warmer, Wetter Planet | author = Kargel, Jeffrey Stuart | url = https://books.google.com/books?id=0QY0U6qJKFUC&dq=mars+future+%22billion+years%22+sun&pg=PA509 | page = 509 | isbn = 978-1852335687 | date = 2004 | publisher = Springer | accessdate =29 October 2007
}}
</ref>

<ref name="ng4_264">
{{cite journal | title = Reconciling the Hemispherical Structure of Earth's Inner Core With its Super-Rotation | last1 = Waszek | first1 = Lauren | last2 = Irving | first2 = Jessica | last3 = Deuss | first3 = Arwen | date = 20 February 2011 | journal = Nature Geoscience | volume = 4 | issue = 4 | pages = 264–267 | bibcode = 2011NatGe...4..264W | doi = 10.1038/ngeo1083
}}
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<ref name="compo">
{{Cite book | chapter = Compositional Model for the Earth's Core | last = McDonough | first = W. F. | date = 2004 | journal = Treatise on Geochemistry | volume = 2 | pages = 547–568 | doi = 10.1016/B0-08-043751-6/02015-6 | bibcode = 2003TrGeo...2..547M | isbn = 978-0080437514
}}
</ref>

<ref name="magnet">
{{cite journal | last1 = Luhmann | first1 = J. G. | last2 = Johnson | first2 = R. E. | last3 = Zhang | first3 = M. H. G. | title = Evolutionary impact of sputtering of the Martian atmosphere by O<sup>+</sup> pickup ions | journal = [[Geophysical Research Letters]] | volume = 19 | issue = 21 | pages = 2151–2154 | date = 1992 | bibcode = 1992GeoRL..19.2151L | doi = 10.1029/92GL02485
}}
</ref>

<ref name="wander">
{{cite journal | title = On the Long Term Evolution of the Spin of the Earth | last1 = Neron de Surgey | first1 = O. | last2 = Laskar | first2 = J. | date = 1996 | journal = Astronomy and Astrophysics | volume = 318 | page = 975| bibcode = 1997A&A...318..975N
}}
</ref>

<ref name="chaos">{{cite news | title = Study: Earth May Collide With Another Planet | publisher = [[Fox News]] | url = http://www.foxnews.com/story/0,2933,525706,00.html | date = 11 June 2009 | accessdate = 8 September 2011 | archive-url = https://web.archive.org/web/20121104012159/http://www.foxnews.com/story/0,2933,525706,00.html | archive-date = 4 November 2012 | url-status = dead | df = dmy-all }}</ref>

<ref name="venus">
{{cite news | title = Science: Fiery Future for Planet Earth | author = Hecht, Jeff | work = New Scientist | url = https://www.newscientist.com/article/mg14219191.900-science-fiery-future-for-planet-earth-.html | date = 2 April 1994 | issue = 1919 | page = 14 | accessdate =29 October 2007
}}
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<ref name="triton">
{{cite journal | title = Tidal Evolution in the Neptune-Triton System | last1 = Chyba | first1 = C. F. | last2 = Jankowski | first2 = D. G. | last3 = Nicholson | first3 = P. D. | date = 1989 | journal = [[Astronomy and Astrophysics]] | volume = 219 | issue = 1–2 | page = 23 | bibcode = 1989A&A...219L..23C
}}
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<ref name="cox">
{{cite journal | title = The Collision Between The Milky Way And Andromeda | author = Cox, J. T. | author2 = Loeb, Abraham | journal = Monthly Notices of the Royal Astronomical Society | date = 2007 | doi = 10.1111/j.1365-2966.2008.13048.x | volume = 386 | issue = 1 | pages = 461–474 | bibcode = 2008MNRAS.386..461C | arxiv = 0705.1170
| s2cid = 14964036 }}
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<ref name="milk">
{{cite journal
 |title=Colliding molecular clouds in head-on galaxy collisions
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 |last2=Lisenfeld
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 |display-authors=3
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 |first4=E.
 |last5=Charmandaris
 |first5=V.
 |last6=Leon
 |first6=S.
 |journal=Astronomy and Astrophysics
 |volume=418
 |issue=2
 |pages=419–428
 |date=2004
 |doi=10.1051/0004-6361:20035732
 |bibcode=2004A&A...418..419B
 |arxiv=astro-ph/0402148
 |s2cid=15928576
 }}
</ref>

<ref name="Schroder 2008">
{{cite journal | last1 = Schroder | first1 = K. P. | last2 = Connon Smith | first2 = Robert | date = 2008 | title = Distant Future of the Sun and Earth Revisited | journal = Monthly Notices of the Royal Astronomical Society | volume = 386 | issue = 1 | pages = 155–163 | bibcode = 2008MNRAS.386..155S | doi = 10.1111/j.1365-2966.2008.13022.x
|arxiv = 0801.4031 | s2cid = 10073988 }}
</ref>

<ref name="Rybicki2001">
{{cite journal | author = Rybicki, K. R. | author2 = Denis, C. | title = On the Final Destiny of the Earth and the Solar System | journal = Icarus | volume = 151 | issue = 1 | pages = 130–137 | date = 2001 | doi = 10.1006/icar.2001.6591 | bibcode = 2001Icar..151..130R
}}
</ref>

<ref name="powell2007">{{cite web | first1=David | last1=Powell | date=22 January 2007 | title=Earth's Moon Destined to Disintegrate | work=Space.com | publisher=Tech Media Network | url=http://www.space.com/scienceastronomy/070122_temporary_moon.html | accessdate=1 June 2010 }}</ref>

<ref name="Titan">{{cite journal | title = Titan under a red giant sun: A new kind of "habitable" moon | author = Lorenz, Ralph D. | author2 = Lunine, Jonathan I. | author3 = McKay, Christopher P. | journal = Geophysical Research Letters | date = 1997 | volume = 24 | pages = 2905–2908 | url = http://www.lpl.arizona.edu/~rlorenz/redgiant.pdf | accessdate = 21 March 2008 | doi = 10.1029/97GL52843 | pmid = 11542268 | issue = 22 | bibcode = 1997GeoRL..24.2905L | citeseerx = 10.1.1.683.8827 | s2cid = 14172341 | archive-date = 24 July 2011 | archive-url = https://web.archive.org/web/20110724173621/http://www.lpl.arizona.edu/~rlorenz/redgiant.pdf | url-status = dead }}</ref>

<ref name="nebula">
{{cite web | author = Balick, Bruce | title = Planetary Nebulae and the Future of the Solar System | publisher = University of Washington | url = http://www.astro.washington.edu/balick/WFPC2/ | accessdate = 23 June 2006 | archive-url = https://web.archive.org/web/20081219010229/http://www.astro.washington.edu/balick/WFPC2/ | archive-date = 19 December 2008 | url-status = dead }}
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{{cite journal | display-authors=1 | last1 = Kalirai | first1 = Jasonjot S. | last2 = Hansen | first2 = Brad M. S. | last3 = Kelson | first3 = Daniel D. | last4 = Reitzel | first4 = David B. | last5 = Rich | first5 = R. Michael | last6 = Richer | first6 = Harvey B. | title = The Initial-Final Mass Relation: Direct Constraints at the Low-Mass End | journal = The Astrophysical Journal | volume = 676 | issue = 1 | pages = 594–609 | date = March 2008 | doi = 10.1086/527028 | bibcode = 2008ApJ...676..594K
|arxiv = 0706.3894 | s2cid = 10729246 }}
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{{cite journal | last = Vila | first = Samuel C. | title = Evolution of a 0.6 M_{sun} White Dwarf | journal = Astrophysical Journal | date = 1971 | volume = 170 | issue = 153 | doi = 10.1086/151196 | bibcode = 1971ApJ...170..153V
}}
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{{cite book | first1 = Robin M. | last1 = Canup | first2 = Kevin | last2 = Righter | title = Origin of the Earth and Moon | volume = 30 | series=The University of Arizona space science series | publisher = University of Arizona Press | date = 2000 | isbn = 978-0816520732 | pages = 176–177 | url = https://books.google.com/books?id=8i44zjcKm4EC&pg=PA176
}}
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<ref name="galaxy">
{{cite journal | title = Cosmology with Hypervelocity Stars | author = Loeb, Abraham | journal = Harvard University | date = 2011 | arxiv = 1102.0007 |bibcode= 2011JCAP...04..023L|doi=10.1088/1475-7516/2011/04/023 | volume=2011 | issue = 4 | page=023| s2cid = 118750775 }}
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{{cite book | last = Chown | first = Marcus | title = Afterglow of Creation | url = https://archive.org/details/afterglowofcreat00chow | url-access = registration | publisher = University Science Books | date = 1996 | page = [https://archive.org/details/afterglowofcreat00chow/page/210 210]| isbn = 9780935702408 }}{{ISBN missing}}
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{{cite journal | last1 = Adams | first1 = F. C. | last2 = Graves | first2 = G. J. M. | last3 = Laughlin | first3 = G. | title = Gravitational Collapse: From Massive Stars to Planets. / First Astrophysics meeting of the Observatorio Astronomico Nacional. / A meeting to celebrate Peter Bodenheimer for his outstanding contributions to Astrophysics: Red Dwarfs and the End of the Main Sequence | editor1-first = G. | editor1-last = García-Segura | editor2-first = G. | editor2-last = Tenorio-Tagle | editor3-first = J. | editor3-last = Franco | editor4-first = H. W. | editor4-last = Yorke | journal = Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias) | volume = 22 | pages = 46–49 | date= December 2004 | bibcode = 2004RMxAC..22...46A
}} See Fig. 3.
</ref>

<ref name="strip">
{{cite book | author = Tayler, Roger John | date = 1993 | title = Galaxies, Structure and Evolution|edition=2 | publisher = Cambridge University Press | page = 92 | isbn = 978-0521367103
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<ref name="five degs">
{{cite book | title = The Anthropic Cosmological Principle | last1 = Barrow | first1 = John D. | author1-link = John D. Barrow | last2 = Tipler | first2 = Frank J.| author2-link = Frank J. Tipler | others= foreword by [[John Archibald Wheeler|John A. Wheeler]] | isbn = 978-0192821478 | id = [http://lccn.loc.gov/87028148 LC 87-28148] | url = https://books.google.com/books?id=uSykSbXklWEC| date = 19 May 1988 | publisher = Oxford University Press | location = Oxford
}}
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<ref name="five ages pp85–87">
{{cite book | last1 = Adams | first1 = Fred | last2 = Laughlin | first2 = Greg | date = 1999 | title = The Five Ages of the Universe | url = https://archive.org/details/fiveagesofuniver0000adam | publisher = The Free Press | location = New York | pages = [https://archive.org/details/fiveagesofuniver0000adam/page/85 85]–87 | isbn = 978-0684854229
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<ref name="dyson">
{{cite journal | title = Time Without End: Physics and Biology in an Open Universe | author = Dyson, Freeman J. | journal = Reviews of Modern Physics | volume = 51 | issue = 3 | pages = 447–460 | date = 1979 | url = http://www.aleph.se/Trans/Global/Omega/dyson.txt| accessdate =5 July 2008 | doi = 10.1103/RevModPhys.51.447 | bibcode = 1979RvMP...51..447D
}}
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{{cite journal | first = K.-P. | last = Schröder | date = 2008 | title = Distant Future of the Sun and Earth Revisited | doi = 10.1111/j.1365-2966.2008.13022.x | journal = Monthly Notices of the Royal Astronomical Society | volume = 386 | issue = 1 | pages = 155–163 | last2 = Connon Smith | first2 = Robert | bibcode = 2008MNRAS.386..155S | arxiv = 0801.4031
}}
</ref-->

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{{cite journal | author = Sackmann, I. J. | author2 = Boothroyd, A. J. | author3 = Kraemer, K. E. | title = Our Sun. III. Present and Future | page = 457 | journal = Astrophysical Journal | date = 1993 | volume = 418 | bibcode = 1993ApJ...418..457S | doi = 10.1086/173407
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<ref name="proton">
{{cite journal | author = Nishino | year = 2009 | title = Search for Proton Decay via {{Subatomic particle|Proton+}} → {{Subatomic particle|Positron}}{{Subatomic particle|pion0}} and {{Subatomic particle|Proton+}} → {{Subatomic particle|Muon+}}{{Subatomic particle|pion0}} in a Large Water Cherenkov Detector | journal = [[Physical Review Letters]] | volume = 102 | issue = 14 | page = 141801 | doi = 10.1103/PhysRevLett.102.141801 | bibcode = 2009PhRvL.102n1801N | name-list-style = vanc | author2 = Super-K Collaboration | display-authors = 2 | last3 = Abe | first3 = K. | last4 = Hayato | first4 = Y. | last5 = Iida | first5 = T. | last6 = Ikeda | first6 = M. | last7 = Kameda | first7 = J. | last8 = Kobayashi | first8 = K. | last9 = Koshio | first9 = Y. | last10 = Miura | first10 = M. | last11 = Moriyama | first11 = S. | last12 = Nakahata | first12 = M. | last13 = Nakayama | first13 = S. | last14 = Obayashi | first14 = Y. | last15 = Ogawa | first15 = H. | last16 = Sekiya | first16 = H. | last17 = Shiozawa | first17 = M. | last18 = Suzuki | first18 = Y. | last19 = Takeda | first19 = A. | last20 = Takenaga | first20 = Y. | last21 = Takeuchi | first21 = Y. | last22 = Ueno | first22 = K. | last23 = Ueshima | first23 = K. | last24 = Watanabe | first24 = H. | last25 = Yamada | first25 = S. | last26 = Hazama | first26 = S. | last27 = Higuchi | first27 = I. | last28 = Ishihara | first28 = C. | last29 = Kajita | first29 = T. | last30 = Kaneyuki | first30 = K. | authorlink2 = Super-Kamiokande | pmid=19392425
|arxiv = 0903.0676 | s2cid = 32385768 }}
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<ref name="half-life">
{{cite book | url = https://archive.org/details/oneuniverse00neil | title = One Universe: At Home in the Cosmos | first1 = Neil de Grasse | last1 = Tyson | last2 = Tsun-Chu Liu | first2 = Charles | last3 = Irion | first3 = Robert | publisher = Joseph Henry Press | date = 2000 | isbn = 978-0309064880 | url-access = registration }}
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<ref name="Page 1976">
{{cite journal | title = Particle Emission Rates from a Black Hole: Massless Particles from an Uncharged, Nonrotating Hole | last = Page | first = Don N. | date = 1976 | journal = Physical Review D | volume = 13 | issue = 2 | pages = 198–206 | bibcode = 1976PhRvD..13..198P | doi = 10.1103/PhysRevD.13.198
}} See in particular equation (27).
</ref>

<ref name="hayes07">
{{cite journal | author = Hayes, Wayne B. | title = Is the Outer Solar System Chaotic? | journal = Nature Physics | arxiv = astro-ph/0702179 | date = 2007 | volume = 3 | issue = 10 | pages = 689–691 | doi = 10.1038/nphys728 | bibcode = 2007NatPh...3..689H
| citeseerx = 10.1.1.337.7948 | s2cid = 18705038 }}
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<ref name="time">{{cite magazine | title = Hurtling Through the Void | magazine = [[Time (magazine)|Time]] | url = http://www.time.com/time/magazine/article/0,9171,926062,00.html | accessdate = 5 September 2011 | date = 20 June 1983 | archive-date = 17 October 2011 | archive-url = https://web.archive.org/web/20111017095230/http://www.time.com/time/magazine/article/0,9171,926062,00.html | url-status = dead }}</ref>

<ref name="glob">
{{cite web | url = http://www.news.cornell.edu/releases/Nov99/Arecibo.message.ws.html | title = Cornell News: "It's the 25th Anniversary of Earth's First (and only) Attempt to Phone E.T." |date= 12 November 1999 |publisher=Cornell University | accessdate =29 March 2008 | archiveurl = https://web.archive.org/web/20080802005337/http://www.news.cornell.edu/releases/Nov99/Arecibo.message.ws.html | archivedate = 2 August 2008
}}
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<!-- <ref name="voyager">
{{cite web | title = Voyager: The Interstellar Mission | publisher = NASA | url = http://voyager.jpl.nasa.gov/mission/interstellar.html | accessdate =5 September 2011
}}
</ref>-->

<ref name="keo1">
{{cite web | title = KEO FAQ | url = http://www.keo.org/uk/pages/faq.html#q1|publisher=keo.org| accessdate =14 October 2011
}}

</ref>

<!-- <ref name="Pioneer 1st 7 billion">{{cite web | title = Pioneer 10 Spacecraft Nears 25TH Anniversary, End of Mission | publisher = nasa.gov | url = http://www.nasa.gov/home/hqnews/1997/97-031.txt | accessdate =22 December 2013}}</ref>
<ref name="Pioneer 1st 7 billion2">{{cite web | title = Space Flight 2003 – United States Space Activities | publisher = nasa.gov | url = http://www.nasa.gov/directorates/somd/reports/2003/us.html| accessdate =22 December 2013}}</ref>-->

<ref name="Pioneer Ames">{{cite web | title = The Pioneer Missions | publisher = NASA | url = http://www.nasa.gov/centers/ames/missions/archive/pioneer.html | accessdate = 5 September 2011 | archive-date = 15 August 2011 | archive-url = https://web.archive.org/web/20110815233221/http://www.nasa.gov/centers/ames/missions/archive/pioneer.html | url-status = dead }}</ref>

<ref name="longnow">
{{cite web | title = The Long Now Foundation | publisher = The Long Now Foundation | url = http://longnow.org/about/ | date = 2011 | accessdate =21 September 2011
}}
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<ref name="brandon">
{{cite journal
| last1 = Carter
| first1 = Brandon
| authorlink = Brandon Carter
| last2 = McCrea
| first2 = W. H.
| date = 1983
| title = The anthropic principle and its implications for biological evolution
| journal = [[Philosophical Transactions of the Royal Society|Philosophical Transactions of the Royal Society of London]]
| volume = A310
| issue = 1512
| pages = 347–363
| doi = 10.1098/rsta.1983.0096
|bibcode = 1983RSPTA.310..347C | s2cid = 92330878
}}
</ref>

<ref name="typeiii">
{{cite web
| authorlink = Michio Kaku
| last = Kaku
| first = Michio
| date = 2010
| title = The Physics of Interstellar Travel: To one day, reach the stars
| url = http://mkaku.org/home/?page_id=250
| publisher=mkaku.org
| accessdate =29 August 2010
}}
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<!-- currently not used
<ref name="sublight">
{{cite web | first = I. A. | last = Crawford | publisher = Scientific American | url = http://www.scientificamerican.com/article.cfm?id=where-are-they | title = Where are They? Maybe we are alone in the galaxy after all | date = July 2000 | accessdate =20 July 2012
}}
</ref>
-->
<ref name="global1">
{{cite book | title = Global Catastrophic Risks | editor1-last = Bostrom | editor1-first = Nick | editor2-last = Cirkovic | editor2-first = Milan M. | last = Adams | first = Fred C. | chapter= Long-term astrophysicial processes | pages = 33–47 | publisher = Oxford University Press | date = 2008}}{{ISBN missing}}
</ref>

<ref name="lageos">{{cite web | title = LAGEOS 1, 2 | publisher = NASA | url = http://space.jpl.nasa.gov/msl/QuickLooks/lageosQL.html | accessdate = 21 July 2012 | archive-date = 21 July 2011 | archive-url = https://web.archive.org/web/20110721062751/http://space.jpl.nasa.gov/msl/QuickLooks/lageosQL.html | url-status = dead }}</ref>

<ref name="pressure">
{{cite journal | author = Li King-Fai | author2 = Pahlevan, Kaveh | author3 = Kirschvink, Joseph L. | author4 = Yung, Luk L. | date = 2009 | title = Atmospheric pressure as a natural climate regulator for a terrestrial planet with a biosphere | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 106 | issue = 24 | pages = 9576–9579 | doi = 10.1073/pnas.0809436106
|bibcode = 2009PNAS..106.9576L | pmid=19487662 | pmc=2701016| doi-access = free }}
</ref>

<ref name="natgeo">{{cite web|title=Gamma-Ray Burst Caused Mass Extinction?|author= Minard, Anne|publisher= National Geographic News|date=2009|url=http://news.nationalgeographic.com/news/2009/04/090403-gamma-ray-extinction.html|accessdate=27 August 2012
}}</ref>

<ref name="Cohen">
{{cite journal | last = Cohen | first = Bernard L. | title = Breeder Reactors: A Renewable Energy Source | journal = American Journal of Physics | volume = 51 | issue = 1 | page = 75 | date= January 1983 | bibcode = 1983AmJPh..51...75C | url = http://large.stanford.edu/publications/coal/references/docs/pad11983cohen.pdf | doi = 10.1119/1.13440
}}
</ref>

<ref name=hess5_4_569>{{cite journal |last1=Bounama |first1=Christine |year=2001 |last2=Franck |first2=S. |last3=Von Bloh |first3=David |title=The fate of Earth's ocean |journal=Hydrology and Earth System Sciences |volume=5 |issue=4 |pages=569–575 |doi=10.5194/hess-5-569-2001 |bibcode=2001HESS....5..569B|doi-access=free }}</ref>

<ref name=loeb_2016>{{cite journal |last1=Loeb |first1=Abraham |year=2016 |last2=Batista |first2=Rafael |last3=Sloan |first3=W. |title=Relative Likelihood for Life as a Function of Cosmic Time |journal=Journal of Cosmology and Astroparticle Physics |volume=2016 |issue=8 |pages=040 | arxiv = 1606.08448 |doi=10.1088/1475-7516/2016/08/040|bibcode=2016JCAP...08..040L |s2cid=118489638 }}</ref>
}}

{{Millennia}}
[[Category:Future]]