# Timeline of the far future

scientific projections regarding the far future
(Redirected from 4th millennium)

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.

Artist's idea of the Earth several billion years from now, when the Sun is a red giant.

Some types of science can say what could happen far into the future.[1] Before we go further, it is worth noting that our local group of galaxies are bound by gravitation, and its changes and aging can be discussed separate from the rest of the universe.

For example, astrophysics can say how planets and stars form, affect each other, and die; particle physics can say how atoms 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 continents shift over time. By observing the past and present, astrophysicists, particle physicists, evolutionary biologists and geologists can make 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.[2] For example, stars will eventually run out of hydrogen fuel and burn out.[3]

## 4th millennium

The 4th millennium will be the millenium after the current millennium. It will start on January 1, 3001 and will end on December 21, 4000.

## Key

 Astronomy and astrophysics Geology and planetary science Biology Particle physics Mathematics 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.

Years from now Event
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 levels would rise 3 to 4 meters.[4]
10,000[note 1] The red supergiant star Antares will have exploded in a supernova by this time.[5]
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 warmer in the northern hemisphere. This is because the northern hemisphere will be facing towards the Sun when Earth is closest to the Sun and away from the Sun when Earth is furthest away from the Sun.[6]
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, as it had 5,000–10,000 years ago.[7][8]
17,000[note 1] Best-guess recurrence rate for a "civilization-threatening" supervolcanic eruption large enough to throw up 1,000 gigatons of pyroclastic material.[9][10]
25,000 The northern Martian polar ice cap could recede as Mars becomes warmer during its c. 50,000-year perihelion precession aspect of its Milankovitch cycle.[11][12]
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.[13] It will recede after about 8,000 years. Then Alpha Centauri and then Gliese 445 will be the nearest stars again[13] (see timeline).
50,000 According to Berger and Loutre (2002), the current interglacial period will end,[14] 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.[15]

Niagara Falls will have worn away the rock underneath it all the way to Lake Erie, so it will not be a waterfall.[16]

The many glacial lakes of the Canadian Shield will have been erased by post-glacial rebound and erosion.[17]

50,000 The length of the day used for astronomical timekeeping reaches about 86,401 SI seconds because lunar tides will have made the Earth's rotation slow down.[18]
100,000 Many of the constellations will look very different as the stars move.[19]
100,000[note 1] The hypergiant star VY Canis Majoris will likely have exploded in a supernova.[20]
100,000 Native North American earthworms, such as Megascolecidae, will have spread north through the United States Upper Midwest to the Canada–US border, recovering from the Laurentide Ice Sheet glaciation (38°N to 49°N), assuming a migration rate of 10 meters per year.[21] (Humans have already introduced non-native invasive earthworms of North America.)
> 100,000 As one of the long-term effects of global warming, 10% of anthropogenic carbon dioxide will still remain in a stabilized atmosphere.[22]
250,000 Lōʻihi, the youngest volcano in the Hawaiian–Emperor seamount chain, will rise above the surface of the ocean and become a new volcanic island.[23]
c. 300,000[note 1] 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.[24][25]
500,000[note 1] Earth will likely have been hit by an asteroid of roughly 1 km in diameter, assuming that people cannot stop it.[26]
500,000 The rugged terrain of Badlands National Park in South Dakota will have eroded away completely.[27]
1 million Meteor Crater, a large impact crater in Arizona considered the "freshest" of its kind, will have eroded away.[28]
1 million[note 1] Longest estimated time until the red supergiant star Betelgeuse explodes in a supernova. For at least a few months, the supernova will be visible on Earth in daylight after the light reaches Earth.[29][30]
1 million[note 1] Desdemona and Cressida, moons of Uranus, will likely have collided.[31]
1.28 ± 0.05 million The star Gliese 710 will pass as close as 0.0676 parsecs—0.221 light-years (14,000 astronomical units)[32] to the Sun before moving away. Its gravity will change things in the Oort cloud, a ring of icy rocks orbiting at the edge of the Solar System. That will make it more likely that a comet will hit something in the inner Solar System.[33]
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.[34]
2 million+ The Grand Canyon will erode further, deepening slightly, but principally widening into a broad valley surrounding the Colorado River.[35]
2.7 million Average orbital half-life of current centaur planets. These planets are unstable because of gravity from outer planets.[36] See predictions for notable centaurs.
10 million The East African Rift valley will become wider and be flooded by the Red Sea, causing a new ocean basin to divide the continent of Africa[37] and the African Plate into the Nubian Plate and the Somali Plate.
10 million Estimated time for full recovery of biodiversity after a potential Holocene extinction, if it were as large as the five previous major extinction events.[38]

Even without a mass extinction, by this time most current species will have disappeared through the background extinction rate, with many clades gradually evolving into new forms.[39][40]

10 million – 1 billion[note 1] Cupid and Belinda, moons of Uranus, will likely have collided.[31]
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. This will form a new inland sea on the West Coast of North America.[41]
50 million Maximum estimated time before the moon Phobos crashes into Mars.[42]
50 million According to Christopher R. Scotese, the movement of the San Andreas Fault will move Los Angeles and San Francisco so that they will have to be one city if people still live there by then.[41] The Californian coast will begin to be subducted into the Aleutian Trench.[43]

Africa will crash into Eurasia and close the Mediterranean Basin. This will create a mountain range similar to the Himalayas.[44]

The peaks of the Appalachian Mountains will erode away[45] if the weathering takes place at 5.7 Bubnoff units. The mountains will change in other ways too. The valleys will deepen twice as fast.[46]

50–60 million The Canadian Rockies will erode away to a plain, assuming a rate of 60 Bubnoff units.[47] The Southern Rockies in the United States are eroding at a somewhat slower rate.[48]
50–400 million Estimated time for Earth to naturally replenish its fossil fuel reserves.[49]
80 million The Big Island will sink beneath the surface of the ocean. But there will be other Hawaiian islands by then.[50]
100 million[note 1] By this time, it is likely have an asteroid about as big as the one that killed some of the dinosaurs 66 million years ago will hit the Earth, if people cannot stop it.[51]
100 million According to the Pangaea Proxima Model created by Christopher R. Scotese, the plate tectonics of the Atlantic Ocean will change, and the Americas will begin to move toward Africa.[41]
100 million The rings of Saturn will change or disappear.[52]
110 million The Sun will be 1% brighter.[53]
180 million A day on Earth will be one hour longer than it is today because the planet is slowly slowing down.[54]
230 million This is as far ahead as people can predict the orbits of the planets because of Lyapunov time.[55]
240 million The Solar System will travel one whole orbit around the Galactic Center.[56]
250 million Because of plate tectonics, the coast of California will hit Alaska.[41]
250–350 million All the continents on Earth may fuse into a supercontinent. Scientists have predicted the Amasia, Novopangaea, and Pangaea Ultima.[41][57] This will likely result in a glacial period, lowering sea levels and increasing oxygen levels, further lowering global temperatures.[58][59]
>250 million Rapid biological evolution may occur if this supercontinent forms, causing lower temperatures and higher oxygen levels.[59] 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.[60]
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%.[60]
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.[61]
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.[62][63][57]
400–500 million The supercontinent (Pangaea Ultima, Novopangaea, or Amasia) will likely separate into other continents again.[57] This will likely result in higher global temperatures, similar to the Cretaceous period.[59]
500 million[note 1] 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 mass extinction. This assumes that an explosion like this one caused the Ordovician–Silurian extinction event. However, the supernova would have to be in exactly the right place and angle to have any negative effect.[64]
600 million Tidal acceleration moves the Moon far enough from Earth that it can no longer cause a total solar eclipse.[65]
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 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.[66] By this time, carbon dioxide levels will fall to the point at which [[C3 carbon fixation|Template:C3 photosynthesis]] is no longer possible. All plants that utilize Template:C3 photosynthesis (≈99 percent of present-day species) will die.[67] The extinction of Template: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 Template:C3 herbaceous plants, followed by deciduous forests, evergreen broad-leaf forests and finally evergreen conifers.[60]
500–800 million[note 1] As Earth begins to rapidly warm 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, adapting to desiccation, or associating with fungi. These adaptations are likely to appear near the beginning of the moist greenhouse.[60] 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 better off because of their ability to travel large distances looking for cooler temperatures.[68] 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.[68]
800–900 million Carbon dioxide levels fall to the point at which [[C4 carbon fixation|Template:C4 photosynthesis]] is no longer possible.[67] 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.[69] 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 termites or those near hydrothermal vents such as worms of the genus Riftia.[60] The only life left on the Earth after this will be single-celled organisms.
1 billion[note 2] 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.[70]
1.1 billion The Sun will be 10% brighter, causing Earth's surface temperatures to reach an average of around 320 K (47 °C; 116 °F). The atmosphere will become a "moist greenhouse," which will make the oceans evaporate.[66][71] This would cause plate tectonics to stop completely, if not already stopped before this time.[72] Pockets of water may still be present at the poles, allowing a place for very simple life to live.[73][74]
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.[75][76][77]
1.3 billion Eukaryotic life dies out on Earth due to carbon dioxide starvation. Only prokaryotes, such as bacteria, are still there.[69]
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.[69][78]
1.6 billion Lower estimate until all prokaryotic life on Earth will go extinct.[69]
2 billion High estimate until the Earth's oceans evaporate if the atmospheric pressure were to decrease via the nitrogen cycle.[79]
2.3 billion The Earth's outer core freezes if the inner core continues to grow at its current rate of 1 mm (0.039 in) per year.[80][81] Without its liquid outer core, the Earth's magnetic field shuts down,[82] and charged particles emanating from the Sun gradually deplete the atmosphere.[83]
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.[71]
2.8 billion Earth's surface temperature will reach around 420 K (147 °C; 296 °F), even at the poles.[66][84]
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.[66][84]
c. 3 billion[note 1] 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.[85]
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.[86]
3.3 billion 1% chance that Jupiter's gravity may make Mercury's orbit so 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 Earth.[87]
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 worse, and the Sun's will be 35-40% brighter than it is now, which will also make it worse. This will make the Earth's 1,400 K (1,130 °C; 2,060 °F)—hot enough to melt some surface rock.[72][79][88][89] Many people say that the Earth's in this part of the futureTemplate:Quantify will be like Venus is today, but the temperature will really be around two times the temperature on Venus today. Earth will have a partially melted surface,[90] 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.
3.6 billion Neptune's 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 like Saturn's.[91]
4 billion Median point by which the Andromeda Galaxy will have collided with the Milky Way. Then they would be one galaxy named "Milkomeda."[92] There is also a small chance of the Solar System being ejected.[93][94] The planets of the Solar System will almost certainly not be disturbed by these events.[95][96][97]
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.[78]
5.4 billion The Sun will run out of hydrogen to turn into helium. So the Sun will finish the main sequence of its life as a star. It will begins evolve into a red giant.[98]
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 happen to Mars.[78]
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.[78]
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.[98][note 3] Before they fall into the Sun, the Moon might 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.[99]

During this era, Saturn's moon Titan may reach surface temperatures necessary to support life.[100]

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 life, 256 times the present-day value.[101] In the process, Mercury, Venus, and very likely Earth will be destroyed.[98]
8 billion The Sun will become a carbon–oxygen white dwarf with about 54.05% its present mass.[98][102][103][104] At this point, if somehow the Earth 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.
22 billion
50 billion If the Earth and Moon are not engulfed by the Sun, by this time they will become tidally locked, with each showing only one face to the other so that there is no day or night.[105][106] 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.[107]
65 billion The Moon may end up colliding with the Earth, assuming the Earth and Moon are not engulfed by the red giant Sun.[108]
100–150 billion The Universe's expansion causes all galaxies beyond the former Milky Way's Local Group to disappear beyond the cosmic light horizon, so that anyone then living on or near Earth will not be able ot tell they are there.[109]
150 billion The cosmic microwave background will cool from its current temperature of c. 2.7 K to 0.3 K, rendering it undetectable with current technology.[110]
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 100 million times, and even individual exiled stars will be alone.[111]
450 billion Median point by which the c. 47 galaxies[112] of the Local Group will come together into a single large galaxy.[113]
800 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 stage of peak luminosity.[114]
1012 (1 trillion) Low estimate for the time until star formation ends in galaxies as galaxies run out of gas clouds that become stars.[113]

The Universe's expansion, assuming a constant dark energy density, multiplies the wavelength of the cosmic microwave background by 1029, 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 hypervelocity stars.[109]

1011–1012 (100 billion – 1 trillion) Estimated time until the Universe ends via the Big Crunch, assuming a "closed" model.[115][116] Depending on how long the expansion phase is, the events in the contraction phase will happen in the reverse order.[117] Galaxy superclusters would first merge, followed by galaxy clusters and then later galaxies. Eventually, stars 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 2,400 K (2,130 °C; 3,860 °F) around 500,000 years before the end, followed by 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 holes. 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.[117] 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.
1.05×1012 (1.05 trillion) Estimated time by which the Universe will have expanded by a factor of more than 1026, 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.[111]
2×1012 (2 trillion) Estimated time by which all objects beyond our Local Group are redshifted by a factor of more than 1053. Even the highest energy gamma rays are stretched so that their wavelength is greater than the physical diameter of the horizon.[118]
4×1012 (4 trillion) Estimated time until the red dwarf star Proxima Centauri, the closest star to the Sun at a distance of 4.25 light-years, leaves the main sequence and becomes a white dwarf.[119]
1013 (10 trillion) Estimated time when the universe will be easiest for life as we know it to live in, on average, unless habitability around low-mass stars is suppressed.[120]
1.2×1013 (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 M.[121][122]
3×1013 (30 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.[123]
1014 (100 trillion) High estimate for the time by which normal star formation ends in galaxies.[113] This marks the transition from the Stelliferous Era to the Degenerate Era. There will be no free hydrogen to make new stars. So all stars that are already there will slowly run out of fuel and die.[3] By this time, the universe will have expanded by a factor of approximately 102554.[111]
1.1–1.2×1014 (110–120 trillion) Time by which all stars in the universe will have run out of fuel (the longest-lived stars, low-mass red dwarfs, have lifespans of roughly 10–20 trillion years).[113] After this point, objects that are as big as stars today will be mostly stellar remnants (white dwarfs, neutron stars, black holes) and brown dwarfs.

Collisions between brown dwarfs will create a few new red dwarfs: on average, about 100 stars will be shining in what was once the Milky Way. Collisions between stellar remnants will create occasional supernovae.[113]

1015 (1 quadrillion) Estimated time until stellar close encounters cause all planets in star systems to be thrown away into space.[113]

By this point, the Sun will have cooled to 5 K.[124]

1019 to 1020
(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.[113][125]
1020 (100 quintillion) Estimated time until the Earth crashes into with the black dwarf Sun because its orbit will decay from emission of gravitational radiation.[126] 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.[126]
1030 Estimated time until those stars not ejected from galaxies (1–10%) fall into their galaxies' central supermassive black holes. By this point, with binary stars 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.[113]
2×1036 Estimated time for all nucleons in the observable universe to decay. This will only happen if the hypothesized proton half-life takes its smallest possible value (8.2×1033 years).[127][128][note 4]
3×1043 Estimated time for all nucleons in the observable universe to decay, if the hypothesized proton half-life takes the largest possible value, 1041 years,[113] assuming that the Big Bang was inflationary and that the same process that made baryons predominate over anti-baryons in the early Universe makes protons decay.[128][note 4] By this time, if protons do decay, the Black Hole Era, in which black holes are the only things left in space, begins.[3][113]
1065 If protons 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.[126]
2×1066 Estimated time until a black hole of 1 solar mass decays into subatomic particles because of Hawking radiation.[129]
6×1099 Estimated time until the supermassive black hole of TON 618 disappears because of emission of Hawking radiation. As of 2018, TON 618 was the largest known black hole. It had a mass of 66 billion solar masses,[129] assuming zero angular momentum (that it does not rotate).
1.7×10106 Estimated time until any supermassive black hole with a mass of 20 trillion solar masses decays by Hawking radiation.[129] 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.[3][113]
10139 2018 estimate of Standard Model lifetime before collapse of a false vacuum; 95% confidence interval is 1058 to 10241 years due in part to uncertainty about the top quark mass.[130]
10200 Estimated latest time for all nucleons in the observable universe to decay, if they do not already decay for one of the reasons named above, through higher-order baryon non-conservation processes, virtual black holes, sphalerons, or other cauess, on time scales of 1046 to 10200 years.[3]
101100-32000 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.[131]
101500 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.[126]
${\displaystyle 10^{10^{26}}}$ [note 5][note 6] Latest possible estimated time until all iron stars collapse via quantum tunnelling into black holes, assuming no proton decay or virtual black holes.[126]

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 M and the Chandrasekhar limit[132]) will collapse into neutron stars. Then, 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 10100 years), and the universe will go into the Dark Era.

${\displaystyle 10^{10^{50}}}$ [note 1][note 6][note 7] Estimated time for a Boltzmann brain to appear in the vacuum because there will be less spontaneous entropy.[133]
${\displaystyle 10^{10^{76}}}$ [note 6] High estimate for the time until all iron stars collapse into black holes, assuming no proton decay or virtual black holes,[126] 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.

${\displaystyle 10^{10^{120}}}$ [note 6] Highest estimate for the time it takes for the universe to reach its final energy state, even in the presence of a false vacuum.[133]
${\displaystyle 10^{10^{10^{56}}}}$ [note 1][note 6] If it is possible, this is when quantum effects will cause a new Big Bang, which will make a new universe. Around this time, quantum tunnelling in any isolated patch of the now-empty universe could generate new inflationary events, resulting in new Big Bangs giving birth to new universes.[134]

Because the total number of ways in which all the subatomic particles in the observable universe could be combined is ${\displaystyle 10^{10^{115}}}$ ,[135][136] a number which, when multiplied by ${\displaystyle 10^{10^{10^{56}}}}$ , 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 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 the landscape predicted by string theory.[137][138]

## Humanity

Years from now Event
10,000 This could be the longest technological civilization could last, according to Frank Drake's original formulation of the Drake equation.[139]
10,000 If human beings 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.[140]
10,000 Humanity has a 95% probability of 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.[141]
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.[142]
100,000+ Time required to 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.[143]
1 million Estimated shortest time by which humanity could colonize our Milky Way galaxy and become capable of harnessing all the energy of the galaxy, assuming a velocity of 10% the speed of light.[144]
2 million Vertebrate species separated for this long will generally undergo allopatric speciation.[145] Evolutionary biologist James W. Valentine predicted that if humanity travels to different places in 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."[146] This would be a natural process of isolated populations, so it would happen even if people invent genetic enhancement technology.
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.[147]
100 million This is the longest technological civilization could last, according to Frank Drake's original formulation of the Drake equation.[148]
1 billion Estimated time for an 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 to pull on the Earth.[149][150]

## Spacecraft and space exploration

As of 2020, five 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 space. So long as they do not crash into anything, these machines should persist indefinitely.[151]

Years from now Event
4000 The SNAP-10A nuclear satellite will return to the surface. It was launched in 1965 and its orbit is 700 km (430 mi) high off the surface of the planet.[152][153]
16,900 Voyager 1 will pass within 3.5 light-years of Proxima Centauri.[154]
18,500 Pioneer 11 will pass within 3.4 light-years of Alpha Centauri.[154]
20,300 Voyager 2 will pass within 2.9 light-years of Alpha Centauri.[154]
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.[155] This is the only 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.[156] Any reply will take at least another 25,000 years to reach it, assuming faster-than-light communication is impossible.
33,800 Pioneer 10 will pass within 3.4 light-years of Ross 248.[154]
34,400 Pioneer 10 will pass within 3.4 light-years of Alpha Centauri.[154]
42,200 Voyager 2 will pass within 1.7 light-years of Ross 248.[154]
44,100 Voyager 1 will pass within 1.8 light-years of Gliese 445.[154]
46,600 Pioneer 11 will pass within 1.9 light-years of Gliese 445.[154]
50,000 The KEO space time capsule, if it is launched, will reenter Earth's atmosphere.[157]
90,300 Pioneer 10 will pass within 0.76 light-years of HIP 117795.[154]
306,100 Voyager 1 will pass within 1 light-year of TYC 3135-52-1.[154]
492,300 Voyager 1 will pass within 1.3 light-years of HD 28343.[154]
800,000–8 million This is the earliest that the Pioneer 10 plaque will wear out: the etching on it will become invisible because of interstellar erosion.[158]
1.2 million Pioneer 11 will come within 3 light-years of Delta Scuti.[154]
1.3 million Pioneer 10 will come within 1.5 light-years of HD 52456.[154]
2 million Pioneer 10 will pass near the bright star Aldebaran.[159]
4 million Pioneer 11 will pass near one of the stars in the constellation Aquila.[159]
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.[160]
1 billion By this time the two Voyager Golden Records will wear out until no one can read them any more.[161]
1020 (100 quintillion) Estimated timescale for the Pioneer and Voyager spacecraft to collide with a star (or ruins of a star).[154]

## 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.

Date or years from now Event
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.[162]
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 Bet Project.[163]

Estimated lifespan of the HD-Rosetta analog disc, an 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).

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.[164]
1 million Estimated lifespan of Memory of Mankind (MOM) self storage-style repository in Hallstatt salt mine in Austria, which stores information on inscribed tablets of stoneware.[165]
1 million Planned lifespan of the Human Document Project being developed at the University of Twente in the Netherlands.[166]
292 million Numeric overflow in system time for Java computer programs.[167]
1 billion Estimated lifespan of "Nanoshuttle memory device" using an iron nanoparticle moved as a molecular switch through a carbon nanotube, a technology developed at the University of California at Berkeley.[168]
more than 13 billion Estimated lifespan of "Superman memory crystal" data storage using femtosecond laser-etched nanostructures in glass.[169][170]
292 billion Numeric overflow in system time for 64-bit Unix systems.[171]

## Human constructs

Years from now Event
50,000 This is about how long tetrafluoromethane lasts in the atmosphere. Tetrafluoromethane is the greenhouse gas that lasts the longest.[172]
1 million Current glass objects in the environment will decompose.[173]

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 mm in 1,000 years, or ≈1 inch in 25,000 years).[174]

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.[175]

The footprints that Neil Armstrong and other Apollo astronauts left on the Moon will be erased by space weathering.[176][177] (The Moon does not have wind and rain the way Earth does, so erosion takes longer.)

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.[178]
100 million Future archaeologists should be able to identify an "Urban Stratum" of fossilized great coastal cities, mostly by looking at underground things, such as building foundations and utility tunnels.[179]

## Nuclear power

Years from now Event
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 six UN languages and Navajo) and in pictograms.[180] 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.
24,000 The Chernobyl Exclusion Zone, the 2,600-square-kilometre (1,000 sq mi) area of Ukraine and Belarus that people had to leave after Chernobyl nuclear power plant blew up in 1986, will return to normal levels of radiation.[181]
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 new sources of fuel are found.[182]
60,000 The amount of fuel for fission-based light-water reactors 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.[182]
211,000 Half-life of technetium-99, the most important long-lived fission product in nuclear waste from uranium.
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.[183]
15.7 million Half-life of iodine-129, the most durable long-lived fission product in nuclear waste from uranium.
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.[184]
5 billion If people manage to collect all the uranium from seawater, this is when the fuel for fission-based breeder reactors will run out, assuming people use as much energy as they did in 1983.[185]
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.[184]

## Notes

1. This represents the time by which the event will most probably have happened. It may occur randomly at any time from the present.
2. Units are short scale
3. 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.
4. Around 264 half-lives. Tyson et al. employ the computation with a different value for half-life.
5. ${\displaystyle 10^{10^{26}}}$  is 1 followed by 1026 (100 septillion) zeroes
6. Although listed in years for convenience, the numbers beyond this point are so vast that their digits would remain unchanged regardless of which conventional units they were listed in, be they nanoseconds or star lifespans.
7. ${\displaystyle 10^{10^{50}}}$ is 1 followed by 1050 (100 quindecillion) zeroes

## References

1. Rescher, Nicholas (1998). Predicting the future: An introduction to the theory of forecasting. State University of New York Press. ISBN 978-0791435533.
2. Nave, C.R. "Second Law of Thermodynamics". Georgia State University. Retrieved 3 December 2011.
3. Adams, Fred; Laughlin, Greg (1999). The Five Ages of the Universe. New York: The Free Press. ISBN 978-0684854229.
4. Mengel, M.; A. Levermann (4 May 2014). "Ice plug prevents irreversible discharge from East Antarctica". Nature Climate Change. 4 (6): 451–455. Bibcode:2014NatCC...4..451M. doi:10.1038/nclimate2226.
5. Hockey, T.; Trimble, V. (2010). "Public reaction to a V = −12.5 supernova". The Observatory. 130 (3): 167. Bibcode:2010Obs...130..167H.
6. Plait, Phil (2002). Bad Astronomy: Misconceptions and Misuses Revealed, from Astrology to the Moon Landing "Hoax". John Wiley and Sons. pp. 55–56.[ISBN missing]
7. Mowat, Laura (14 July 2017). "Africa's desert to become lush green tropics as monsoons MOVE to Sahara, scientists say". Express.co.uk. Retrieved 23 March 2018.
8. "Orbit: Earth's Extraordinary Journey". ExptU. 23 December 2015. Archived from the original on 14 July 2018. Retrieved 23 March 2018.
9. "'Super-eruption' timing gets an update — and not in humanity's favour". Nature. 552 (7683): 8. 30 November 2017. doi:10.1038/d41586-017-07777-6. Retrieved 28 August 2020.
10. "Scientists predict a volcanic eruption that would destroy humanity could happen sooner than previously thought". www.independent.co.uk. Retrieved 28 August 2020.
11. Schorghofer, Norbert (23 September 2008). "Temperature response of Mars to Milankovitch cycles" (PDF). Geophysical Research Letters. 35 (18): L18201. Bibcode:2008GeoRL..3518201S. doi:10.1029/2008GL034954. S2CID 16598911. Archived from the original (PDF) on 19 September 2009.
12. Beech, Martin (2009). Terraforming: The Creating of Habitable Worlds. Springer. pp. 138–142. Bibcode:2009tchw.book.....B.
13. Matthews, R. A. J. (Spring 1994). "The Close Approach of Stars in the Solar Neighborhood". Quarterly Journal of the Royal Astronomical Society. 35 (1): 1. Bibcode:1994QJRAS..35....1M.
14. Berger, A & Loutre, MF (2002). "Climate: an exceptionally long interglacial ahead?". Science. 297 (5585): 1287–1288. doi:10.1126/science.1076120. PMID 12193773. S2CID 128923481.
15. "Human-made climate change suppresses the next ice age — Potsdam Institute for Climate Impact Research". www.pik-potsdam.de. Retrieved 2020-10-21.
16. "Niagara Falls Geology Facts & Figures". Niagara Parks. Archived from the original on 19 July 2011. Retrieved 29 April 2011.
17. Bastedo, Jamie (1994). Shield Country: The Life and Times of the Oldest Piece of the Planet. Komatik Series, ISSN 0840-4488. Vol. 4. Arctic Institute of North America of the University of Calgary. p. 202. ISBN 9780919034792.
18. Finkleman, David; Allen, Steve; Seago, John; Seaman, Rob; Seidelmann, P. Kenneth (June 2011). "The Future of Time: UTC and the Leap Second". American Scientist, July–August , V N4 P312. 2011 (99). arXiv:1106.3141. Bibcode:2011arXiv1106.3141F.
19. Tapping, Ken (2005). "The Unfixed Stars". National Research Council Canada. Archived from the original on 8 July 2011. Retrieved 29 December 2010.
20. Monnier, J. D.; Tuthill, P.; Lopez, GB; et al. (1999). "The Last Gasps of VY Canis Majoris: Aperture Synthesis and Adaptive Optics Imagery". The Astrophysical Journal. 512 (1): 351–361. arXiv:astro-ph/9810024. Bibcode:1999ApJ...512..351M. doi:10.1086/306761. S2CID 16672180.
21. Schaetzl, Randall J.; Anderson, Sharon (2005). Soils: Genesis and Geomorphology. Cambridge University Press. p. 105. ISBN 9781139443463.
22. "Frequently Asked Questions". Hawai'i Volcanoes National Park. 2011. Retrieved 22 October 2011.
23. Tuthill, Peter; Monnier, John; Lawrance, Nicholas; Danchi, William; Owocki, Stan; Gayley, Kenneth (2008). "The Prototype Colliding-Wind Pinwheel WR 104". The Astrophysical Journal. 675 (1): 698–710. arXiv:0712.2111. Bibcode:2008ApJ...675..698T. doi:10.1086/527286. S2CID 119293391.
24. Tuthill, Peter. "WR 104: Technical Questions". Retrieved 20 December 2015.
25. Bostrom, Nick (March 2002). "Existential Risks: Analyzing Human Extinction Scenarios and Related Hazards". Journal of Evolution and Technology. 9 (1). Retrieved 10 September 2012.
26. Landstreet, John D. (2003). Physical Processes in the Solar System: An introduction to the physics of asteroids, comets, moons and planets. Keenan & Darlington. p. 121. ISBN 9780973205107.
27. Sessions, Larry (29 July 2009). "Betelgeuse will explode someday". EarthSky Communications, Inc. Retrieved 16 November 2010.
28. "A giant star is acting strange, and astronomers are buzzing". National Geographic. 26 December 2019. Retrieved 15 March 2020.
29. "Uranus's colliding moons". astronomy.com. 2017. Retrieved 23 September 2017.
30. Bailer-Jones, C.A.L.; Rybizki, J; Andrae, R.; Fouesnea, M. (2018). "New stellar encounters discovered in the second Gaia data release". Astronomy & Astrophysics. 616: A37. arXiv:1805.07581. Bibcode:2018A&A...616A..37B. doi:10.1051/0004-6361/201833456. S2CID 56269929.
31. Filip Berski and Piotr A. Dybczyński (25 October 2016). "Gliese 710 will pass the Sun even closer". Astronomy and Astrophysics. 595 (L10): L10. Bibcode:2016A&A...595L..10B. doi:10.1051/0004-6361/201629835.
32. Goldstein, Natalie (2009). Global Warming. Infobase Publishing. p. 53. ISBN 9780816067695. 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.
33. "Grand Canyon – Geology – A dynamic place". Views of the National Parks. National Park Service.
34. Horner, J.; Evans, N.W.; Bailey, M. E. (2004). "Simulations of the Population of Centaurs I: The Bulk Statistics". Monthly Notices of the Royal Astronomical Society. 354 (3): 798–810. arXiv:astro-ph/0407400. Bibcode:2004MNRAS.354..798H. doi:10.1111/j.1365-2966.2004.08240.x. S2CID 16002759.
35. Haddok, Eitan (29 September 2008). "Birth of an Ocean: The Evolution of Ethiopia's Afar Depression". Scientific American. Archived from the original on 24 December 2013. Retrieved 27 December 2010.
36. Kirchner, James W.; Weil, Anne (9 March 2000). "Delayed biological recovery from extinctions throughout the fossil record". Nature. 404 (6774): 177–180. Bibcode:2000Natur.404..177K. doi:10.1038/35004564. PMID 10724168. S2CID 4428714.
37. Wilson, Edward O. (1999). The Diversity of Life. W.W. Norton & Company. p. 216. ISBN 9780393319408.
38. Wilson, Edward Osborne (1992). "The Human Impact". The Diversity of Life. London: Penguin UK (published 2001). ISBN 9780141931739. Retrieved 15 March 2020.
39. Scotese, Christopher R. "Pangea Ultima will form 250 million years in the Future". Paleomap Project. Retrieved 13 March 2006.
40. Bills, Bruce G.; Gregory A. Neumann; David E. Smith; Maria T. Zuber (2005). "Improved estimate of tidal dissipation within Mars from MOLA observations of the shadow of Phobos" (PDF). Journal of Geophysical Research. 110 (E07004): E07004. Bibcode:2005JGRE..110.7004B. doi:10.1029/2004je002376. Archived from the original (PDF) on 25 May 2017. Retrieved 16 September 2015.
41. Garrison, Tom (2009). Essentials of Oceanography (5 ed.). Brooks/Cole. p. 62.[ISBN missing]
42. "Continents in Collision: Pangea Ultima". NASA. 2000. Retrieved 29 December 2010.
43. "Geology". Encyclopedia of Appalachia. University of Tennessee Press. 2011. Archived from the original on 21 May 2014. Retrieved 21 May 2014.
44. Hancock, Gregory; Kirwan, Matthew (January 2007). "Summit erosion rates deduced from 10Be: Implications for relief production in the central Appalachians" (PDF). Geology. 35 (1): 89. Bibcode:2007Geo....35...89H. doi:10.1130/g23147a.1.
45. Yorath, C. J. (2017). Of rocks, mountains and Jasper: a visitor's guide to the geology of Jasper National Park. Dundurn Press. p. 30. ISBN 9781459736122. [...] '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.
46. Dethier, David P.; Ouimet, W.; Bierman, P. R.; Rood, D. H.; et al. (2014). "Basins and bedrock: Spatial variation in 10Be erosion rates and increasing relief in the southern Rocky Mountains, USA" (PDF). Geology. 42 (2): 167–170. Bibcode:2014Geo....42..167D. doi:10.1130/G34922.1.
47. Patzek, Tad W. (2008). "Can the Earth Deliver the Biomass-for-Fuel we Demand?". In Pimentel, David (ed.). Biofuels, Solar and Wind as Renewable Energy Systems: Benefits and Risks. Springer. ISBN 9781402086533.
48. Perlman, David (14 October 2006). "Kiss that Hawaiian timeshare goodbye / Islands will sink in 80 million years". San Francisco Chronicle.
49. Nelson, Stephen A. "Meteorites, Impacts, and Mass Extinction". Tulane University. Retrieved 13 January 2011.
50. Lang, Kenneth R. (2003). The Cambridge Guide to the Solar System. Cambridge University Press. p. 329. ISBN 9780521813068. [...] all the rings should collapse [...] in about 100 million years.
51. Schröder, K.-P.; Connon Smith, Robert (2008). "Distant future of the Sun and Earth revisited". Monthly Notices of the Royal Astronomical Society. 386 (1): 155–63. arXiv:0801.4031. Bibcode:2008MNRAS.386..155S. doi:10.1111/j.1365-2966.2008.13022.x. S2CID 10073988.
52. Jillian Scudder. "How Long Until The Moon Slows The Earth to a 25 Hour Day?". Forbes. Retrieved 30 May 2017.
53. Hayes, Wayne B. (2007). "Is the Outer Solar System Chaotic?". Nature Physics. 3 (10): 689–691. arXiv:astro-ph/0702179. Bibcode:2007NatPh...3..689H. CiteSeerX 10.1.1.337.7948. doi:10.1038/nphys728. S2CID 18705038.
54. Leong, Stacy (2002). "Period of the Sun's Orbit Around the Galaxy (Cosmic Year)". The Physics Factbook. Retrieved 2 April 2007.
55. Williams, Caroline; Nield, Ted (20 October 2007). "Pangaea, the comeback". New Scientist. Archived from the original on 13 April 2008. Retrieved 2 January 2014.
56. Calkin and Young in 1996 on pages 9–75
57. Thompson and Perry in 1997 on pages 127–28
58. O'Malley-James, Jack T.; Greaves, Jane S.; Raven, John A.; Cockell, Charles S. (2014). "Swansong Biosphere II: The final signs of life on terrestrial planets near the end of their habitable lifetimes". International Journal of Astrobiology. 13 (3): 229–243. arXiv:1310.4841. Bibcode:2014IJAsB..13..229O. doi:10.1017/S1473550413000426. S2CID 119252386.
59. Strom, Robert G.; Schaber, Gerald G.; Dawson, Douglas D. (25 May 1994). "The global resurfacing of Venus". Journal of Geophysical Research. 99 (E5): 10899–10926. Bibcode:1994JGR....9910899S. doi:10.1029/94JE00388.
60. Nield in 2007 on pages 20–21
61. Hoffman in 1992 on pages 323–27
62. Minard, Anne (2009). "Gamma-Ray Burst Caused Mass Extinction?". National Geographic News. Retrieved 27 August 2012.
63. "Questions Frequently Asked by the Public About Eclipses". NASA. Archived from the original on 12 March 2010. Retrieved 7 March 2010.
64. O'Malley-James, Jack T.; Greaves, Jane S.; Raven, John A.; Cockell, Charles S. (2012). "Swansong Biospheres: Refuges for life and novel microbial biospheres on terrestrial planets near the end of their habitable lifetimes". International Journal of Astrobiology. 12 (2): 99–112. arXiv:1210.5721. Bibcode:2013IJAsB..12...99O. doi:10.1017/S147355041200047X. S2CID 73722450.
65. Heath, Martin J.; Doyle, Laurance R. (2009). "Circumstellar Habitable Zones to Ecodynamic Domains: A Preliminary Review and Suggested Future Directions". arXiv:0912.2482 [astro-ph.EP].
66. Ward & Brownlee in 2003 on pages 117-28
67. Franck, S.; Bounama, C.; Von Bloh, W. (November 2005). "Causes and timing of future biosphere extinction" (PDF). Biogeosciences Discussions. 2 (6): 1665–1679. Bibcode:2005BGD.....2.1665F. doi:10.5194/bgd-2-1665-2005. S2CID 3619702.
68. Bounama, Christine; Franck, S.; Von Bloh, David (2001). "The fate of Earth's ocean". Hydrology and Earth System Sciences. 5 (4): 569–575. Bibcode:2001HESS....5..569B. doi:10.5194/hess-5-569-2001.
69. Schröder, K.-P.; Connon Smith, Robert (1 May 2008). "Distant future of the Sun and Earth revisited". Monthly Notices of the Royal Astronomical Society. 386 (1): 155–163. arXiv:0801.4031. Bibcode:2008MNRAS.386..155S. doi:10.1111/j.1365-2966.2008.13022.x. S2CID 10073988.
70. Brownlee 2010, p. 95.
71. Brownlee, Donald E. (2010). "Planetary habitability on astronomical time scales". In Schrijver, Carolus J.; Siscoe, George L. (eds.). Heliophysics: Evolving Solar Activity and the Climates of Space and Earth. Cambridge University Press. ISBN 978-0521112949.
72. Li King-Fai; Pahlevan, Kaveh; Kirschvink, Joseph L.; Yung, Luk L. (2009). "Atmospheric pressure as a natural climate regulator for a terrestrial planet with a biosphere". Proceedings of the National Academy of Sciences of the United States of America. 106 (24): 9576–9579. Bibcode:2009PNAS..106.9576L. doi:10.1073/pnas.0809436106. PMC 2701016. PMID 19487662.
73. Caldeira, Ken; Kasting, James F (1992). "The life span of the biosphere revisited". Nature. 360 (6406): 721–23. Bibcode:1992Natur.360..721C. doi:10.1038/360721a0. PMID 11536510. S2CID 4360963.
74. Franck, S. (2000). "Reduction of biosphere life span as a consequence of geodynamics". Tellus B. 52 (1): 94–107. Bibcode:2000TellB..52...94F. doi:10.1034/j.1600-0889.2000.00898.x.
75. Timothy M, von Bloh; Werner (2001). "Biotic feedback extends the life span of the biosphere". Geophysical Research Letters. 28 (9): 1715–18. Bibcode:2001GeoRL..28.1715L. doi:10.1029/2000GL012198. S2CID 16152753.
76. Kargel, Jeffrey Stuart (2004). Mars: A Warmer, Wetter Planet. Springer. p. 509. ISBN 978-1852335687. Retrieved 29 October 2007.
77. Li, King-Fai; Pahlevan, Kaveh; Kirschvink, Joseph L.; Yung, Yuk L. (16 June 2009). "Atmospheric pressure as a natural climate regulator for a terrestrial planet with a biosphere". Proceedings of the National Academy of Sciences of the United States of America. 106 (24): 9576–9579. Bibcode:2009PNAS..106.9576L. doi:10.1073/pnas.0809436106. PMC 2701016. PMID 19487662.
78. Waszek, Lauren; Irving, Jessica; Deuss, Arwen (20 February 2011). "Reconciling the Hemispherical Structure of Earth's Inner Core With its Super-Rotation". Nature Geoscience. 4 (4): 264–267. Bibcode:2011NatGe...4..264W. doi:10.1038/ngeo1083.
79. McDonough, W. F. (2004). "Compositional Model for the Earth's Core". Treatise on Geochemistry. Vol. 2. pp. 547–568. Bibcode:2003TrGeo...2..547M. doi:10.1016/B0-08-043751-6/02015-6. ISBN 978-0080437514. `{{cite book}}`: Missing or empty `|title=` (help)
80. Luhmann, J. G.; Johnson, R. E.; Zhang, M. H. G. (1992). "Evolutionary impact of sputtering of the Martian atmosphere by O+ pickup ions". Geophysical Research Letters. 19 (21): 2151–2154. Bibcode:1992GeoRL..19.2151L. doi:10.1029/92GL02485.
81. Quirin Shlermeler (3 March 2005). "Solar wind hammers the ozone layer". News@nature. doi:10.1038/news050228-12.
82. Adams, Fred C. (2008). "Long-term astrophysicial processes". In Bostrom, Nick; Cirkovic, Milan M. (eds.). Global Catastrophic Risks. Oxford University Press. pp. 33–47.[ISBN missing]
83. Adams 2008, pp. 33–44.
84. Neron de Surgey, O.; Laskar, J. (1996). "On the Long Term Evolution of the Spin of the Earth". Astronomy and Astrophysics. 318: 975. Bibcode:1997A&A...318..975N.
85. "Study: Earth May Collide With Another Planet". Fox News. 11 June 2009. Archived from the original on 4 November 2012. Retrieved 8 September 2011.
86. Guinan, E. F.; Ribas, I. (2002). Montesinos, Benjamin; Gimenez, Alvaro; Guinan, Edward F. (eds.). "Our Changing Sun: The Role of Solar Nuclear Evolution and Magnetic Activity on Earth's Atmosphere and Climate". ASP Conference Proceedings. 269: 85–106. Bibcode:2002ASPC..269...85G.
87. Kasting, J. F. (June 1988). "Runaway and moist greenhouse atmospheres and the evolution of earth and Venus". Icarus. 74 (3): 472–494. Bibcode:1988Icar...74..472K. doi:10.1016/0019-1035(88)90116-9. PMID 11538226.
88. Hecht, Jeff (2 April 1994). "Science: Fiery Future for Planet Earth". New Scientist. No. 1919. p. 14. Retrieved 29 October 2007.
89. Chyba, C. F.; Jankowski, D. G.; Nicholson, P. D. (1989). "Tidal Evolution in the Neptune-Triton System". Astronomy and Astrophysics. 219 (1–2): 23. Bibcode:1989A&A...219L..23C.
90. Cox, J. T.; Loeb, Abraham (2007). "The Collision Between The Milky Way And Andromeda". Monthly Notices of the Royal Astronomical Society. 386 (1): 461–474. arXiv:0705.1170. Bibcode:2008MNRAS.386..461C. doi:10.1111/j.1365-2966.2008.13048.x. S2CID 14964036.
91. Cain, Fraser (2007). "When Our Galaxy Smashes Into Andromeda, What Happens to the Sun?". Universe Today. Archived from the original on 17 May 2007. Retrieved 2007-05-16.
92. Cox, T. J.; Loeb, Abraham (2008). "The Collision Between The Milky Way And Andromeda". Monthly Notices of the Royal Astronomical Society. 386 (1): 461–474. arXiv:0705.1170. Bibcode:2008MNRAS.386..461C. doi:10.1111/j.1365-2966.2008.13048.x. S2CID 14964036.
93. NASA (31 May 2012). "NASA's Hubble Shows Milky Way is Destined for Head-On Collision". NASA. Retrieved 13 October 2012.
94. Dowd, Maureen (29 May 2012). "Andromeda Is Coming!". The New York Times. Retrieved 9 January 2014. [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.
95. Braine, J.; Lisenfeld, U.; Duc, P. A.; et al. (2004). "Colliding molecular clouds in head-on galaxy collisions". Astronomy and Astrophysics. 418 (2): 419–428. arXiv:astro-ph/0402148. Bibcode:2004A&A...418..419B. doi:10.1051/0004-6361:20035732. S2CID 15928576.
96. Schroder, K. P.; Connon Smith, Robert (2008). "Distant Future of the Sun and Earth Revisited". Monthly Notices of the Royal Astronomical Society. 386 (1): 155–163. arXiv:0801.4031. Bibcode:2008MNRAS.386..155S. doi:10.1111/j.1365-2966.2008.13022.x. S2CID 10073988.
97. Powell, David (22 January 2007). "Earth's Moon Destined to Disintegrate". Space.com. Tech Media Network. Retrieved 1 June 2010.
98. Lorenz, Ralph D.; Lunine, Jonathan I.; McKay, Christopher P. (1997). "Titan under a red giant sun: A new kind of "habitable" moon" (PDF). Geophysical Research Letters. 24 (22): 2905–2908. Bibcode:1997GeoRL..24.2905L. CiteSeerX 10.1.1.683.8827. doi:10.1029/97GL52843. PMID 11542268. S2CID 14172341. Retrieved 21 March 2008.
99. Rybicki, K. R.; Denis, C. (2001). "On the Final Destiny of the Earth and the Solar System". Icarus. 151 (1): 130–137. Bibcode:2001Icar..151..130R. doi:10.1006/icar.2001.6591.
100. Balick, Bruce. "Planetary Nebulae and the Future of the Solar System". University of Washington. Archived from the original on 19 December 2008. Retrieved 23 June 2006.
101. Kalirai, Jasonjot S.; et al. (March 2008). "The Initial-Final Mass Relation: Direct Constraints at the Low-Mass End". The Astrophysical Journal. 676 (1): 594–609. arXiv:0706.3894. Bibcode:2008ApJ...676..594K. doi:10.1086/527028. S2CID 10729246.
102. Based upon the weighted least-squares best fit on p. 16 of Kalirai et al. with the initial mass equal to a solar mass.
103. Murray, C.D. & Dermott, S.F. (1999). Solar System Dynamics. Cambridge University Press. p. 184. ISBN 978-0-521-57295-8.
104. Dickinson, Terence (1993). From the Big Bang to Planet X. Camden East, Ontario: Camden House. pp. 79–81. ISBN 978-0-921820-71-0.
105. Canup, Robin M.; Righter, Kevin (2000). Origin of the Earth and Moon. The University of Arizona space science series. Vol. 30. University of Arizona Press. pp. 176–177. ISBN 978-0-8165-2073-2.
106. Dorminey, Bruce (31 January 2017). "Earth and Moon May Be on Long-Term Collision Course". Forbes. Retrieved 11 February 2017.
107. Loeb, Abraham (2011). "Cosmology with Hypervelocity Stars". Harvard University. 2011 (4): 023. arXiv:1102.0007. Bibcode:2011JCAP...04..023L. doi:10.1088/1475-7516/2011/04/023. S2CID 118750775.
108. Chown, Marcus (1996). Afterglow of Creation. University Science Books. p. 210. ISBN 9780935702408.[ISBN missing]
109. Busha, Michael T.; Adams, Fred C.; Wechsler, Risa H.; Evrard, August E. (2003-10-20). "Future Evolution of Structure in an Accelerating Universe". The Astrophysical Journal. 596 (2): 713–724. arXiv:astro-ph/0305211. doi:10.1086/378043. ISSN 0004-637X. S2CID 15764445.
110. "The Local Group of Galaxies". University of Arizona. Students for the Exploration and Development of Space. Retrieved 2 October 2009.
111. Adams, Fred C.; Laughlin, Gregory (1997). "A dying universe: the long-term fate and evolution of astrophysical objects". Reviews of Modern Physics. 69 (2): 337–372. arXiv:astro-ph/9701131. Bibcode:1997RvMP...69..337A. doi:10.1103/RevModPhys.69.337. S2CID 12173790.
112. Adams, F. C.; Graves, G. J. M.; Laughlin, G. (December 2004). García-Segura, G.; Tenorio-Tagle, G.; Franco, J.; Yorke, H. W. (eds.). "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". Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias). 22: 46–49. Bibcode:2004RMxAC..22...46A. See Fig. 3.
113. Adams, Fred C.; Laughlin, Gregory (1997). "A dying universe: the long-term fate and evolution of astrophysical objects". Reviews of Modern Physics. 69 (2): 337–72. arXiv:astro-ph/9701131. Bibcode:1997RvMP...69..337A. doi:10.1103/RevModPhys.69.337. S2CID 12173790.
114. Wang, Yun; Kratochvil, Jan Michael; Linde, Andrei; Shmakova, Marina (2004). "Current observational constraints on cosmic doomsday". Journal of Cosmology and Astroparticle Physics. 2004 (12): 006. arXiv:astro-ph/0409264. Bibcode:2004JCAP...12..006W. doi:10.1088/1475-7516/2004/12/006. S2CID 56436935.
115. Davies, Paul (1997). The Last Three Minutes: Conjectures About The Ultimate Fate of the Universe. Basic Books. ISBN 978-0-465-03851-0.
116. Krauss, Lawrence M.; Starkman, Glenn D. (March 2000). "Life, The Universe, and Nothing: Life and Death in an Ever-Expanding Universe". The Astrophysical Journal. 531 (1): 22–30. arXiv:astro-ph/9902189. Bibcode:2000ApJ...531...22K. doi:10.1086/308434. ISSN 0004-637X. S2CID 18442980.
117. Fred C. Adams; Gregory Laughlin; Genevieve J. M. Graves (2004). "RED Dwarfs and the End of The Main Sequence" (PDF). Revista Mexicana de Astronomía y Astrofísica, Serie de Conferencias. 22: 46–49.
118. Loeb, Abraham; Batista, Rafael; Sloan, W. (2016). "Relative Likelihood for Life as a Function of Cosmic Time". Journal of Cosmology and Astroparticle Physics. 2016 (8): 040. arXiv:1606.08448. Bibcode:2016JCAP...08..040L. doi:10.1088/1475-7516/2016/08/040. S2CID 118489638.
119. "Why the Smallest Stars Stay Small". Sky & Telescope (22). November 1997.
120. Adams, F. C.; P. Bodenheimer; G. Laughlin (2005). "M dwarfs: planet formation and long term evolution". Astronomische Nachrichten. 326 (10): 913–919. Bibcode:2005AN....326..913A. doi:10.1002/asna.200510440.
121. Tayler, Roger John (1993). Galaxies, Structure and Evolution (2 ed.). Cambridge University Press. p. 92. ISBN 978-0521367103.
122. Barrow, John D.; Tipler, Frank J. (19 May 1988). The Anthropic Cosmological Principle. foreword by John A. Wheeler. Oxford: Oxford University Press. ISBN 978-0192821478. LC 87-28148.
123. Adams, Fred; Laughlin, Greg (1999). The Five Ages of the Universe. New York: The Free Press. pp. 85–87. ISBN 978-0684854229.
124. Dyson, Freeman J. (1979). "Time Without End: Physics and Biology in an Open Universe". Reviews of Modern Physics. 51 (3): 447–460. Bibcode:1979RvMP...51..447D. doi:10.1103/RevModPhys.51.447. Retrieved 5 July 2008.
125. Nishino, Super-K Collaboration, et al. (2009). "Search for Proton Decay via Error no symbol defined → Error no symbol definedError no symbol defined and Error no symbol defined → Error no symbol definedError no symbol defined in a Large Water Cherenkov Detector". Physical Review Letters. 102 (14): 141801. arXiv:0903.0676. Bibcode:2009PhRvL.102n1801N. doi:10.1103/PhysRevLett.102.141801. PMID 19392425. S2CID 32385768.
126. Tyson, Neil de Grasse; Tsun-Chu Liu, Charles; Irion, Robert (2000). One Universe: At Home in the Cosmos. Joseph Henry Press. ISBN 978-0309064880.
127. Page, Don N. (1976). "Particle Emission Rates from a Black Hole: Massless Particles from an Uncharged, Nonrotating Hole". Physical Review D. 13 (2): 198–206. Bibcode:1976PhRvD..13..198P. doi:10.1103/PhysRevD.13.198. See in particular equation (27).
128. Andreassen, Anders; Frost, William; Schwartz, Matthew D. (12 March 2018). "Scale-invariant instantons and the complete lifetime of the standard model". Physical Review D. 97 (5): 056006. arXiv:1707.08124. Bibcode:2018PhRvD..97e6006A. doi:10.1103/PhysRevD.97.056006. S2CID 118843387.
129. M. E. Caplan (7 August 2020). "Black Dwarf Supernova in the Far Future" (PDF). MNRAS. 497 (1–6): 4357–4362. arXiv:2008.02296. doi:10.1093/mnras/staa2262.
130. K. Sumiyoshi, S. Yamada, H. Suzuki, W. Hillebrandt (21 July 1997). "The fate of a neutron star just below the minimum mass: does it explode?". Astronomy and Astrophysics. 334: 159. arXiv:astro-ph/9707230. Bibcode:1998A&A...334..159S. Given this assumption... the minimum possible mass of a neutron star is 0.189`{{cite journal}}`: CS1 maint: multiple names: authors list (link)
131. Linde, Andrei. (2007). "Sinks in the Landscape, Boltzmann Brains and the Cosmological Constant Problem". Journal of Cosmology and Astroparticle Physics. 2007 (1): 022. arXiv:hep-th/0611043. Bibcode:2007JCAP...01..022L. CiteSeerX 10.1.1.266.8334. doi:10.1088/1475-7516/2007/01/022. S2CID 16984680.
132. Carroll, Sean M.; Chen, Jennifer (27 October 2004). "Spontaneous Inflation and the Origin of the Arrow of Time". arXiv:hep-th/0410270.
133. Tegmark, M (7 February 2003). "Parallel universes. Not just a staple of science fiction, other universes are a direct implication of cosmological observations". Sci. Am. 288 (5): 40–51. arXiv:astro-ph/0302131. Bibcode:2003SciAm.288e..40T. doi:10.1038/scientificamerican0503-40. PMID 12701329.
134. Max Tegmark (7 February 2003). "Parallel Universes". 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. 288 (5): 40–51. arXiv:astro-ph/0302131. Bibcode:2003SciAm.288e..40T. doi:10.1038/scientificamerican0503-40. PMID 12701329.
135. M. Douglas (21 March 2003). "The statistics of string / M theory vacua". JHEP. 0305 (46): 046. arXiv:hep-th/0303194. Bibcode:2003JHEP...05..046D. doi:10.1088/1126-6708/2003/05/046. S2CID 650509.
136. S. Ashok; M. Douglas (2004). "Counting flux vacua". JHEP. 0401 (60): 060. arXiv:hep-th/0307049. Bibcode:2004JHEP...01..060A. doi:10.1088/1126-6708/2004/01/060. S2CID 1969475.
137. Smith, Cameron; Davies, Evan T. (2012). Emigrating Beyond Earth: Human Adaptation and Space Colonization. Springer. p. 258.[ISBN missing]
138. Klein, Jan; Takahata, Naoyuki (2002). Where Do We Come From?: The Molecular Evidence for Human Descent. Springer. p. 395. ISBN 9783540425649.[ISBN missing]
139. Carter, Brandon; McCrea, W. H. (1983). "The anthropic principle and its implications for biological evolution". Philosophical Transactions of the Royal Society of London. A310 (1512): 347–363. Bibcode:1983RSPTA.310..347C. doi:10.1098/rsta.1983.0096. S2CID 92330878.
140. Greenberg, Joseph (1987). Language in the Americas. Stanford University Press. pp. 341–342.[ISBN missing]
141. McKay, Christopher P.; Toon, Owen B.; Kasting, James F. (8 August 1991). "Making Mars habitable". Nature. 352 (6335): 489–496. Bibcode:1991Natur.352..489M. doi:10.1038/352489a0. PMID 11538095. S2CID 2815367.
142. Kaku, Michio (2010). "The Physics of Interstellar Travel: To one day, reach the stars". mkaku.org. Retrieved 29 August 2010.
143. Avise, John; D. Walker; G. C. Johns (22 September 1998). "Speciation durations and Pleistocene effects on vertebrate phylogeography". Philosophical Transactions of the Royal Society B. 265 (1407): 1707–1712. doi:10.1098/rspb.1998.0492. PMC 1689361. PMID 9787467.
144. Valentine, James W. (1985). "The Origins of Evolutionary Novelty And Galactic Colonization". In Finney, Ben R.; Jones, Eric M. (eds.). Interstellar Migration and the Human Experience. University of California Press. p. 274.[ISBN missing]
145. J. Richard Gott, III (1993). "Implications of the Copernican principle for our future prospects". Nature. 363 (6427): 315–319. Bibcode:1993Natur.363..315G. doi:10.1038/363315a0. S2CID 4252750.
146. Bignami, Giovanni F.; Sommariva, Andrea (2013). A Scenario for Interstellar Exploration and Its Financing. Springer. p. 23. Bibcode:2013sief.book.....B. ISBN 9788847053373.[ISBN missing]
147. Korycansky, D. G.; Laughlin, Gregory; Adams, Fred C. (2001). "Astronomical engineering: a strategy for modifying planetary orbits". Astrophysics and Space Science. 275 (4): 349–366. arXiv:astro-ph/0102126. Bibcode:2001Ap&SS.275..349K. doi:10.1023/A:1002790227314. hdl:2027.42/41972. S2CID 5550304. Astrophys.Space Sci.275:349-366,2001.
148. Korycansky, D. G. (2004). "Astroengineering, or how to save the Earth in only one billion years" (PDF). Revista Mexicana de Astronomía y Astrofísica. 22: 117–120. Bibcode:2004RMxAC..22..117K.
149. "Hurtling Through the Void". Time. 20 June 1983. Archived from the original on 17 October 2011. Retrieved 5 September 2011.
150. Staub, D.W. (25 March 1967). SNAP 10 Summary Report. Atomics International Division of North American Aviation, Inc., Canoga Park, California. NAA-SR-12073.
151. "U.S. ADMISSION : Satellite mishap released rays". The Canberra Times. Vol. 52, no. 15, 547. Australian Capital Territory, Australia. 30 March 1978. p. 5. Retrieved 12 August 2017 – 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....
152. Coryn A.L. Bailer-Jones, Davide Farnocchia (3 April 2019). "Future stellar flybys of the Voyager and Pioneer spacecraft". Research Notes of the American Astronomical Society. 3 (59): 59. arXiv:1912.03503. Bibcode:2019RNAAS...3...59B. doi:10.3847/2515-5172/ab158e. S2CID 134524048.
153. "Cornell News: "It's the 25th Anniversary of Earth's First (and only) Attempt to Phone E.T."". Cornell University. 12 November 1999. Archived from the original on 2 August 2008. Retrieved 29 March 2008.
154. Dave Deamer. "In regard to the email from". Science 2.0. Archived from the original on 24 September 2015. Retrieved 14 November 2014.
155. "KEO FAQ". keo.org. Retrieved 14 October 2011.
156. Lasher, Lawrence. "Pioneer Mission Status". NASA. Archived from the original on 8 April 2000. [Pioneer's speed is] about 12 km/s... [the plate etching] should survive recognizable at least to a distance ≈10 parsecs, and most probably to 100 parsecs.
157. "The Pioneer Missions". NASA. Retrieved 5 September 2011.
158. "LAGEOS 1, 2". NASA. Archived from the original on 21 July 2011. Retrieved 21 July 2012.
159. Jad Abumrad and Robert Krulwich (12 February 2010). Carl Sagan And Ann Druyan's Ultimate Mix Tape (Radio). National Public Radio.
160. "This Camera Will Capture a 1,000-Year Exposure That Ends in 3015 for History's Slowest Photo". PetaPixel. 5 March 2015. Retrieved 2015-12-14.
161. "The Long Now Foundation". The Long Now Foundation. 2011. Retrieved 21 September 2011.
162. "A Visit to the Doomsday Vault". CBS News. 20 March 2008.
163. "Memory of Mankind". Retrieved 4 March 2019.
164. Begtrup, G. E.; Gannett, W.; Yuzvinsky, T. D.; Crespi, V. H.; et al. (13 May 2009). "Nanoscale Reversible Mass Transport for Archival Memory" (PDF). Nano Letters. 9 (5): 1835–1838. Bibcode:2009NanoL...9.1835B. CiteSeerX 10.1.1.534.8855. doi:10.1021/nl803800c. PMID 19400579. Archived from the original (PDF) on 22 June 2010.
165. Zhang, J.; Gecevičius, M.; Beresna, M.; Kazansky, P. G. (2014). "Seemingly unlimited lifetime data storage in nanostructured glass". Phys. Rev. Lett. 112 (3): 033901. Bibcode:2014PhRvL.112c3901Z. doi:10.1103/PhysRevLett.112.033901. PMID 24484138.
166. Zhang, J.; Gecevičius, M.; Beresna, M.; Kazansky, P. G. (June 2013). "5D Data Storage by Ultrafast Laser Nanostructuring in Glass" (PDF). CLEO: Science and Innovations: CTh5D–9. Archived from the original (PDF) on 6 September 2014.
167. "Date/Time Conversion Contract Language" (PDF). Office of Information Technology Services, New York (state). 19 May 2019. Archived from the original (PDF) on 30 April 2021. Retrieved 16 October 2020.
168. "Tetrafluoromethane". Toxicology Data Network (TOXNET). United States National Library of Medicine. Retrieved 4 September 2014.
169. "Time it takes for garbage to decompose in the environment" (PDF). New Hampshire Department of Environmental Services. Archived from the original (PDF) on 9 June 2014. Retrieved 23 May 2014.
170. Lyle, Paul (2010). Between Rocks And Hard Places: Discovering Ireland's Northern Landscapes. Geological Survey of Northern Ireland.[ISBN missing]
171. Weisman, Alan (10 July 2007). The World Without Us. New York: Thomas Dunne Books/St. Martin's Press. pp. 171–172. ISBN 978-0-312-34729-1. OCLC 122261590.
172. "Apollo 11 – First Footprint on the Moon". Student Features. NASA.
173. Meadows, A. J. (2007). The Future of the Universe. Springer. pp. 81–83. ISBN 9781852339463.[ISBN missing]
174. Weisman, Alan (10 July 2007). The World Without Us. New York: Thomas Dunne Books/St. Martin's Press. p. 182. ISBN 978-0-312-34729-1. OCLC 122261590.
175. Zalasiewicz, Jan (25 September 2008). The Earth After Us: What legacy will humans leave in the rocks?. Oxford University Press., Review in Stanford Archaeolog Archived 2014-05-13 at the Wayback Machine
176. "Permanent Markers Implementation Plan" (PDF). United States Department of Energy. 30 August 2004. Archived from the original (PDF) on 28 September 2006.
177. Time: Disasters that Shook the World. New York City: Time Home Entertainment. 2012. ISBN 978-1-60320-247-3.
178. Fetter, Steve (March 2009). "How long will the world's uranium supplies last?".
179. Biello, David (28 January 2009). "Spent Nuclear Fuel: A Trash Heap Deadly for 250,000 Years or a Renewable Energy Source?". Scientific American.
180. Ongena, J; G. Van Oost (2004). "Energy for future centuries – Will fusion be an inexhaustible, safe and clean energy source?" (PDF). Fusion Science and Technology. 2004. 45 (2T): 3–14. doi:10.13182/FST04-A464. S2CID 15368449. Archived from the original (PDF) on 2016-08-19. Retrieved 2020-10-28.
181. Cohen, Bernard L. (January 1983). "Breeder Reactors: A Renewable Energy Source" (PDF). American Journal of Physics. 51 (1): 75. Bibcode:1983AmJPh..51...75C. doi:10.1119/1.13440.