Unsolved:Timeline of the far future

Short description: Scientific projections regarding the far future

Artist's concept of the carbonized Earth 7.9 billion years from now, after the Sun has entered the red-giant stage.

While the future can never be predicted with absolute certainty, present understanding in various scientific fields allows for the prediction of some far-future events, if only in the broadest outline. These fields include astrophysics, which has revealed how planets and stars form, interact, and die; particle physics, which has revealed how matter behaves at the smallest scales; evolutionary biology, which predicts how life will evolve over time; and plate tectonics, which shows how continents shift over millennia.

All projections of the future of Earth, the Solar System, and the universe must account for the second law of thermodynamics, which states that entropy, or a loss of the energy available to do work, must rise over time. Stars will eventually exhaust their supply of hydrogen fuel and burn out. Close encounters between astronomical objects gravitationally fling planets from their star systems, and star systems from galaxies.

Physicists expect that matter itself will eventually come under the influence of radioactive decay, as even the most stable materials break apart into subatomic particles. Current data suggest that the universe has a flat geometry (or very close to flat), and thus will not collapse in on itself after a finite time, and the infinite future allows for the occurrence of a number of massively improbable events, such as the formation of Boltzmann brains.

The timelines displayed here cover events from the beginning of the 11th millennium to the furthest reaches of future time. A number of alternative future events are listed to account for questions still unresolved, such as whether humans will become extinct, whether protons decay, and whether the Earth survives when the Sun expands to become a red giant.

Key

	Astronomy and astrophysics
	Geology and planetary science
	Biology
	Particle physics
	Mathematics
	Technology and culture

Future of the Earth, the Solar System and the universe

	Years from now	Event
	10,000	If a failure of the Wilkes Subglacial Basin "ice plug" in the next few centuries were to endanger the East Antarctic Ice Sheet, it will take up to this long to melt completely. Sea levels would rise 3 to 4 metres. One of the potential long-term effects of global warming, this is separate from the shorter-term threat of the West Antarctic Ice Sheet.
	10,000	The red supergiant star Antares will likely have exploded in a supernova. The explosion is expected to be easily visible in daylight.
	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 into a tropical climate, as it was 5,000–10,000 years ago.
	25,000	The northern Martian polar ice cap could recede as Mars reaches a warming peak of the northern hemisphere during the c. 50,000-year perihelion precession aspect of its Milankovitch cycle.
	36,000	The small red dwarf Ross 248 will pass within 3.024 light-years of Earth, becoming the closest star to the Sun. It will recede after about 8,000 years, making first Alpha Centauri again and then Gliese 445 the nearest stars (see timeline).
	50,000	According to Berger and Loutre, the current interglacial period ends, sending the Earth back into a glacial period of the current ice age, regardless of the effects of anthropogenic global warming. Niagara Falls will have eroded away the remaining 32 km to Lake Erie, and cease to exist. The many glacial lakes of the Canadian Shield will have been erased by post-glacial rebound and erosion.
	50,000	The length of the day used for astronomical timekeeping reaches about 86,401 SI seconds, due to lunar tides decelerating the Earth's rotation. Under the present-day timekeeping system, either a leap second would need to be added to the clock every single day, or else by then, in order to compensate, the length of the day would have had to have been officially lengthened by one SI second.
	100,000	The proper motion of stars across the celestial sphere, which is the result of their movement through the Milky Way, renders many of the constellations unrecognisable.
	100,000	The hypergiant star VY Canis Majoris will likely have exploded in a hypernova.
	100,000	Earth will likely have undergone a supervolcanic eruption large enough to erupt 400 km3 (96 cubic miles) of magma. For comparison, Lake Erie is 484 km3 (116 cu mi).
	100,000	Native North American earthworms, such as Megascolecidae, will have naturally 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 metres per year. (However, non-native invasive earthworms of North America have already been introduced by humans on a much shorter timescale, causing a shock to the regional ecosystem.)
	>100,000	As one of the long-term effects of global warming, 10% of anthropogenic carbon dioxide will still remain in a stabilized atmosphere.
	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.
	c. 300,000	At some point in the next "several" hundred thousand years, the Wolf–Rayet star WR 104 is expected to explode in a supernova. It has been suggested that it may produce a gamma-ray burst that could pose a threat to life on Earth should its poles be aligned 12° or lower towards Earth. The star's axis of rotation has yet to be determined with certainty.
	500,000	Earth will likely have been hit by an asteroid of roughly 1 km in diameter, assuming it cannot be averted.
	500,000	The rugged terrain of Badlands National Park in South Dakota will have eroded away completely.
	1 million	Meteor Crater, a large impact crater in Arizona considered the "freshest" of its kind, will have eroded away.
	1 million	Earth will likely have undergone a supervolcanic eruption large enough to erupt 3,200 km3 (770 cubic miles) of magma, an event comparable to the Toba supereruption 75,000 years ago.
	1 million	Highest estimated time until the red supergiant star Betelgeuse explodes in a supernova. The explosion is expected to be easily visible in daylight. It may explode in as little as 100,000 years, if particular evolutionary models turn out to be correct.
	1 million	Desdemona and Cressida, moons of Uranus, will likely have collided.
	1.4 million	The star Gliese 710 will pass as close as 9,000 AU (0.14 light-years to the Sun) before moving away. This will gravitationally perturb members of the Oort cloud, a halo of icy bodies orbiting at the edge of the Solar System, thereafter raising the likelihood of a cometary impact in the inner Solar System.
	2 million	Estimated time for the recovery of coral reef ecosystems from human-caused ocean acidification; a similar time was taken for the recovery of marine ecosystems after the acidification event that occurred about 65 million years ago.
	2 million+	The Grand Canyon will erode further, deepening slightly, but principally widening into a broad valley surrounding the Colorado River.
	2.7 million	Average orbital half-life of current centaurs, that are unstable because of gravitational interaction of the several outer planets. See predictions for notable centaurs.
	10 million	The widening East African Rift valley is flooded by the Red Sea, causing a new ocean basin to divide the continent of Africa and the African Plate into the newly formed Nubian Plate and the Somali Plate.
	10 million 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.
	10 to 1,000 million	Cupid and Belinda, moons of Uranus, will likely have collided.
	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.
	50 million	Maximum estimated time before the moon Phobos collides with Mars.
	50 million	According to Christopher R. Scotese, the movement of the San Andreas Fault will cause the current locations of Los Angeles and San Francisco to merge. The Californian coast will begin to be subducted into the Aleutian Trench. Africa's collision with Eurasia closes the Mediterranean Basin and creates a mountain range similar to the Himalayas. The Appalachian Mountains peaks will largely erode away, weathering at 5.7 Bubnoff units, although topography will actually rise as regional valleys deepen at twice this rate.
	50–60 million	The Canadian Rockies will erode away to a plain, assuming a rate of 60 Bubnoff units. The Southern Rockies in the United States are eroding at a somewhat slower rate.
	50–400 million
	80 million	The Big Island will have become the last of the current Hawaiian Islands to sink beneath the surface of the ocean, while a more recently formed chain of "new Hawaiian Islands" will then have emerged in their place.
	100 million	Earth will likely have been hit by an asteroid comparable in size to the one that triggered the K–Pg extinction 66 million years ago, assuming it cannot be averted.
	100 million	According to the Pangaea Proxima Model created by Christopher R. Scotese, a new subduction zone will open in the Atlantic Ocean and the Americas will begin to converge back toward Africa.
	100 million	Upper estimate for lifespan of the rings of Saturn in their current state.
	110 million	The Sun's luminosity has increased by 1%.
	180 million	Due to the gradual slowing down of Earth's rotation, a day on Earth will be one hour longer than it is today.
	230 million	Prediction of the orbits of the planets is impossible over greater time spans than this, due to the limitations of Lyapunov time.
	240 million	From its present position, the Solar System completes one full orbit of the Galactic center.
	250 million	According to Christopher R. Scotese, due to the northward movement of the West Coast of North America, the coast of California will collide with Alaska.
	250–350 million	All the continents on Earth may fuse into a supercontinent. Three potential arrangements of this configuration have been dubbed Amasia, Novopangaea, and Pangaea Ultima. This will likely result in a glacial period, lowering sea levels and increasing oxygen levels, further lowering global temperatures.
	~250 million	Rapid biological evolution may occur due to the formation of a supercontinent, causing lower temperatures and higher oxygen levels.
	292 million	Estimated time frame of which the rings of Saturn are likely to disappear.
	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.
	350 million	According to the extroversion model, first developed by Paul F. Hoffman, the Pacific Ocean will close completely.
	400–500 million	The supercontinent (Pangaea Ultima, Novopangaea, or Amasia) will likely have rifted apart. This will likely result in higher global temperatures, similar to the Cretaceous period.
	500 million	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, assuming the hypothesis is correct that a previous such explosion triggered the Ordovician–Silurian extinction event. However, the supernova would have to be precisely oriented relative to Earth to have any negative effect.
	600 million	Tidal acceleration moves the Moon far enough from Earth that total solar eclipses are no longer possible.
	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. Without volcanoes to recycle carbon into the Earth's atmosphere, carbon dioxide levels begin to fall. By this time, carbon dioxide levels will fall to the point at which C3 photosynthesis is no longer possible. All plants that utilize C3 photosynthesis (≈99 percent of present-day species) will die.
	700–800 million	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, further lowering oxygen levels. Flying animals would be better off because of their ability to travel large distances looking for cooler temperatures. Many animals may be driven to the poles or possibly underground. These creatures would become active during the polar night and hibernate 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.
	800 million	Carbon dioxide levels fall to the point at which C4 photosynthesis is no longer possible. 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 stated that some animal life may be able to survive in the oceans. Eventually, however, all multicellular life will die out. The only life left on the Earth after this will be single-celled organisms.
	1 billion	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 the surface water would remain at the surface.
	1.1 billion	The Sun's luminosity has risen by 10%, causing Earth's surface temperatures to reach an average of c. 320 K (47 °C; 116 °F). The atmosphere will become a "moist greenhouse", resulting in a runaway evaporation of the oceans. This would cause plate tectonics to stop completely, if not already stopped before this time. Pockets of water may still be present at the poles, allowing abodes for simple life.
	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 a complex biosphere unsustainable from this point on.
	1.3 billion	Eukaryotic life dies out on Earth due to carbon dioxide starvation. Only prokaryotes remain.
	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.
	1.6 billion	Lower estimate until all prokaryotic life will go extinct.
	2 billion	High estimate until the Earth's oceans evaporate if the atmospheric pressure were to decrease via the nitrogen cycle.
	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. Without its liquid outer core, the Earth's magnetic field shuts down, and charged particles emanating from the Sun gradually deplete the atmosphere.
	2.55 billion	The Sun will have reached a maximum surface temperature of 5,820 K. From then on, it will become gradually cooler while its luminosity will continue to increase.
	2.8 billion	Earth's surface temperature reaches c. 420 K (147 °C; 296 °F), even at the poles. At this point, all life, now reduced to unicellular colonies in isolated, scattered microenvironments such as high-altitude lakes or caves, will go extinct.
	c. 3 billion	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.
	3 billion	Median point at which the Moon's rising distance from the Earth lessens its stabilising effect on the Earth's axial tilt. As a consequence, Earth's true polar wander becomes chaotic and extreme, leading to dramatic shifts in the planet's climate due to the changing axial tilt.
	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.
	3.5–4.5 billion	All water currently present in oceans (if not lost earlier) evaporates. The greenhouse effect caused by the massive, water-rich atmosphere, combined with the Sun's luminosity reaching roughly 35–40% above its present value, will result in Earth's surface temperature rising to 1,400 K (1,130 °C; 2,060 °F), which is hot enough to melt some surface rock. This period in Earth's future is often compared to Venus today, but the temperature is actually around two times the temperature on Venus today, and at this temperature the surface will be partially molten, while Venus probably has a mostly solid surface at present. Venus will also probably drastically heat up at this time as well, most likely being much hotter than Earth will be as it is closer to the Sun.
	3.6 billion	Neptune's moon Triton falls through the planet's Roche limit, potentially disintegrating into a planetary ring system similar to Saturn's.
	4 billion	Median point by which the Andromeda Galaxy will have collided with the Milky Way, which will thereafter merge to form a galaxy dubbed "Milkomeda". The solar system will most likely enter a new orbit around the merged centre, however there is also a small chance of the solar system being ejected. The planets of the Solar System will almost certainly not be disturbed by these events.
	4.5 billion	Mars reaches the same solar flux the Earth did when it first formed, 4.5 billion years ago from today.
	5.4 billion	With the hydrogen supply exhausted at its core, the Sun leaves the main sequence and begins to evolve into a red giant.
	6.5 billion	Mars reaches the same solar radiation flux as Earth today, after which it will suffer a similar fate to the Earth as described above.
	7.5 billion	Earth and Mars may become tidally locked with the expanding subgiant Sun.
	7.59 billion	The Earth and Moon are very likely destroyed by falling into the Sun, just before the Sun reaches the tip of its red giant phase and its maximum radius of 256 times the present-day value. Before the final collision, the Moon possibly spirals below Earth's Roche limit, breaking into a ring of debris, most of which falls to the Earth's surface. During this era, Saturn's moon Titan may reach surface temperatures necessary to support life.
	7.9 billion	The Sun reaches the tip of the red-giant branch of the Hertzsprung–Russell diagram, achieving its maximum radius of 256 times the present-day value. In the process, Mercury, Venus, and very likely Earth are destroyed.
	8 billion	The Sun becomes a carbon-oxygen white dwarf with about 54.05% its present mass. At this point, if somehow the Earth survives, temperatures on the surface of the planet, as well as other remaining planets in the Solar System, will begin dropping rapidly, due to the white dwarf Sun emitting much less energy than it does today.
	22 billion	The end of the Universe in the Big Rip scenario, assuming a model of dark energy with w = −1.5. If the density of dark energy is less than -1, then the Universe's expansion would continue to accelerate and the Observable Universe would continue to get smaller. Around 200 million years before the rip, galaxy clusters like the Local Group or the Sculptor Group would be destroyed. Sixty million years before the rip, all galaxies will begin to lose stars around their edges and will completely disintegrate in another 40 million years. Three months before the end, all star systems will become gravitationally unbound, and planets will fly off into the rapidly expanding universe. Thirty minutes before the end, planets, stars, asteroids and even extreme objects like neutron stars and black holes will evaporate into atoms. 10−19 seconds before the end, atoms would break apart. Ultimately, once rip reaches the Planck scale, cosmic strings would be disintegrated as well as the fabric of spacetime itself. The universe would enter into a "rip singularity" when all distances become infinitely large. Whereas a "crunch singularity" all matter is infinitely concentrated, in a "rip singularity" all matter is infinitely spread out. However, observations of galaxy cluster speeds by the Chandra X-ray Observatory suggest that the true value of w is c. −0.991, meaning the Big Rip will not occur.
	50 billion	If the Earth and Moon are not engulfed by the Sun, by this time they will become tidelocked, with each showing only one face to the other. Thereafter, the tidal action of the white dwarf Sun will extract angular momentum from the system, causing the lunar orbit to decay and the Earth's spin to accelerate.
	65 billion	The Moon may end up colliding with the Earth due to the decay of its orbit, assuming the Earth and Moon are not engulfed by the red giant Sun.
	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, removing them from the observable universe.
	150 billion	The cosmic microwave background cools from its current temperature of c. 2.7 K to 0.3 K, rendering it essentially undetectable with current technology.
	450 billion	Median point by which the c. 47 galaxies of the Local Group will coalesce into a single large galaxy.
	800 billion	Expected time when the net light emission from the combined "Milkomeda" galaxy begins to decline as the red dwarf stars pass through their blue dwarf stage of peak luminosity.
	1012 (1 trillion)	Low estimate for the time until star formation ends in galaxies as galaxies are depleted of the gas clouds they need to form stars. 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 rendering its evidence of the Big Bang undetectable. However, it may still be possible to determine the expansion of the universe through the study of hypervelocity stars.
	1011 – 1012 (100 billion – 1 trillion)	Estimated time until the Universe ends via the Big Crunch, assuming a "closed" model. Depending on how long the expansion phase is, the events in the contraction phase will happen in the reverse order. Galaxy superclusters would first merge, followed by galaxy clusters and then later galaxies. Eventually, stars have become 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 expel their internal 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 coalescing black holes. Finally, all the black holes in the Universe will merge into one singular black hole containing all the matter in the universe, which would then devour the Universe, including itself. After this, it is possible that a new Big Bang would follow 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. It is also possible that the Universe is a "closed model", but that the curvature is so small that we can't detect it over the distance of the current observable universe.
	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.
	1013 (10 trillion)	Estimated time of peak habitability in the universe, unless habitability around low mass stars is suppressed.
	1.2×1013 (12 trillion)	Estimated time until the red dwarf VB 10, as of 2016 the least massive main sequence star with an estimated mass of 0.075 M☉, runs out of hydrogen in its core and becomes a white dwarf.
	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 disrupted, potentially ejecting them from the system entirely. On average, the closer a planet's orbit to its parent star the longer it takes to be ejected in this manner, because it is gravitationally more tightly bound to the star.
	1014 (100 trillion)	High estimate for the time until normal star formation ends in galaxies. This marks the transition from the Stelliferous Era to the Degenerate Era; with no free hydrogen to form new stars, all remaining stars slowly exhaust their fuel and die.
	1.1–1.2×1014 (110–120 trillion)	Time by which all stars in the universe will have exhausted their fuel (the longest-lived stars, low-mass red dwarfs, have lifespans of roughly 10–20 trillion years). After this point, the stellar-mass objects remaining are stellar remnants (white dwarfs, neutron stars, black holes) and brown dwarfs. Collisions between brown dwarfs will create new red dwarfs on a marginal level: on average, about 100 stars will be shining in what was once the Milky Way. Collisions between stellar remnants will create occasional supernovae.
	1015 (1 quadrillion)	Estimated time until stellar close encounters detach all planets in star systems (including the Solar System) from their orbits. By this point, the Sun will have cooled to five degrees above absolute zero.
	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 in this manner to be ejected from their galaxy. This process eventually causes the Milky Way to eject the majority of its brown dwarfs and stellar remnants.
	1020 (100 quintillion)	Estimated time until the Earth collides with the black dwarf Sun due to the decay of its orbit via emission of gravitational radiation, if the Earth is not ejected from its orbit by a stellar encounter or engulfed by the Sun during its red giant phase.
	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.
	2×1036	Estimated time for all nucleons in the observable universe to decay, if the hypothesized proton half-life takes its smallest possible value (8.2×1033 years).
	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, 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. By this time, if protons do decay, the Black Hole Era, in which black holes are the only remaining celestial objects, begins.
	1065	Assuming that protons do not decay, estimated time for rigid objects, from free-floating rocks in space to planets, to rearrange their atoms and molecules via quantum tunneling. On this timescale, any discrete body of matter "behaves like a liquid" and becomes a smooth sphere due to diffusion and gravity.
	5.8×1068	Estimated time until a stellar mass black hole with a mass of 3 solar masses decays into subatomic particles by Hawking radiation.
	6×1099	Estimated time until the supermassive black hole of TON 618, as of 2018 the most massive known with the mass of 66 billion solar masses, dissipates by the emission of Hawking radiation, assuming zero angular momentum (non-rotating black hole).
	1.7×10106	Estimated time until a supermassive black hole with a mass of 20 trillion solar masses decays by the Hawking process. This marks the end of the Black Hole Era. Beyond this time, if protons do decay, the Universe enters the Dark Era, in which all physical objects have decayed to subatomic particles, gradually winding down to their final energy state in the heat death of the universe.
	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.
	10200	Estimated high time for all nucleons in the observable universe to decay, if they do not via the above process, through any one of many different mechanisms allowed in modern particle physics (higher-order baryon non-conservation processes, virtual black holes, sphalerons, etc.) on time scales of 1046 to 10200 years.
	101500	Assuming protons do not decay, the estimated time until all baryonic matter has either fused together to form iron-56 or decayed from a higher mass element into iron-56 (see iron star).
	[math]\displaystyle{ 10^{10^{26}} }[/math]	Low estimate for the time until all objects exceeding the Planck mass collapse via quantum tunnelling into black holes, assuming no proton decay or virtual black holes. On this vast timescale, even ultra-stable iron stars are destroyed by quantum tunnelling events. First iron stars of sufficient mass (somewhere between 0.2 M☉ and the Chandrasekhar limit. Because when iron stars have 0.2 M☉ or less (neutron stars around 0.2 M☉ are stable), these iron stars are energetically favorable enough to prevent collapse via tunnelling) will collapse via tunnelling into neutron stars. Subsequently, neutron stars and any remaining iron stars less than 0.2 M☉ collapse via tunnelling into black holes. The subsequent evaporation of each resulting black hole into sub-atomic particles (a process lasting roughly 10100 years), and subsequent shift to the Dark Era is on these timescales instantaneous.
	[math]\displaystyle{ 10^{10^{50}} }[/math]	Estimated time for a Boltzmann brain to appear in the vacuum via a spontaneous entropy decrease.
	[math]\displaystyle{ 10^{10^{76}} }[/math]	High estimate for the time until all matter collapses into neutron stars or black holes, assuming no proton decay or virtual black holes, which then (on these timescales) instantaneously evaporate into sub-atomic particles. This is the highest estimate possible time for Black Hole Era (and subsequent Dark Era) to finally commence. Beyond this point, it is almost certain that Universe will not contain any more baryonic matter and the Universe after this time will be near-pure vacuum (possibly accompanied with the presence of a false vacuum), characteristic of Dark Era Universe until it reaches final energy state, assuming it does not happen before this time.
	[math]\displaystyle{ 10^{10^{120}} }[/math]	High estimate for the time for the universe to reach its final energy state, even in the presence of a false vacuum.
	[math]\displaystyle{ 10^{10^{10^{56}}} }[/math]	Around this vast timeframe, quantum tunnelling in any isolated patch of the vacuum could generate, via inflation, new Big Bangs giving birth to new universes. Because the total number of ways in which all the subatomic particles in the observable universe can be combined is [math]\displaystyle{ 10^{10^{115}} }[/math], a number which, when multiplied by [math]\displaystyle{ 10^{10^{10^{56}}} }[/math], disappears into the rounding error, this is also the time required for a quantum-tunnelled and quantum fluctuation-generated Big Bang to produce a new universe identical to our own, assuming that every new universe contained at least the same number of subatomic particles and obeyed laws of physics within the range predicted by string theory.

Future of humanity

	Years from now	Event
	10,000	Most probable estimated lifespan of technological civilization, according to Frank Drake's original formulation of the Drake equation.
	10,000	If globalization trends lead to panmixia, human genetic variation will no longer be regionalized, as the effective population size will equal the actual population size.
	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.
	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 progenitors.
	100,000+	Time required to terraform Mars with an oxygen-rich breathable atmosphere, using only plants with solar efficiency comparable to the biosphere currently found on Earth.
	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.
	2 million
	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.
	100 million	Maximal estimated lifespan of technological civilization, according to Frank Drake's original formulation of the Drake equation.
	1 billion	Estimated time for an astroengineering project to alter the Earth's orbit, compensating for the Sun's rising brightness and outward migration of the habitable zone, accomplished by repeated asteroid gravity assists.

Spacecraft and space exploration

To date five spacecraft (Voyager 1, Voyager 2, Pioneer 10, Pioneer 11 and New Horizons) are on trajectories which will take them out of the Solar System and into interstellar space. Barring an extremely unlikely collision with some object, the craft should persist indefinitely.

	Years from now	Event
	10,000	Pioneer 10 passes within 3.8 light-years of Barnard's Star.
	25,000	The Arecibo message, a collection of radio data transmitted on 16 November 1974, reaches the distance of its destination, the globular cluster Messier 13. This is the only interstellar radio message sent to such a distant region of the galaxy. 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, but as the cluster is 168 light-years in diameter, the message will still reach its destination. Any reply will take at least another 25,000 years from the time of its transmission (assuming faster-than-light communication is impossible).
	32,000	Pioneer 10 passes within 3 light-years of Ross 248.
	40,000	Voyager 1 passes within 1.6 light-years of AC+79 3888, a star in the constellation Camelopardalis also known as Gliese 445.
	50,000	The KEO space time capsule, if it is launched, will reenter Earth's atmosphere.
	296,000	Voyager 2 passes within 4.3 light-years of Sirius, the brightest star in the night sky.
	800,000–8 million	Low estimate of Pioneer 10 plaque lifespan, before the etching is destroyed by poorly-understood interstellar erosion processes.
	2 million	Pioneer 10 passes near the bright star Aldebaran.
	4 million	Pioneer 11 passes near one of the stars in the constellation Aquila.
	8 million	The LAGEOS satellites' orbits will decay, and they will re-enter Earth's atmosphere, carrying with them a message to any far future descendants of humanity, and a map of the continents as they are expected to appear then.
	1 billion	Estimated lifespan of the two Voyager Golden Records, before the information stored on them is rendered unrecoverable.

Technological projects

	Years from now	Event
	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. 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.
	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.
	1 million	Planned lifespan of the Human Document Project being developed at the University of Twente in the Netherlands.
	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.
	more than 13 billion	Estimated lifespan of "Superman memory crystal" data storage using femtosecond laser-etched nanostructures in glass, a technology developed at the University of Southampton.

Human constructs

	Years from now	Event
	50,000	Estimated atmospheric lifetime of tetrafluoromethane, the most durable greenhouse gas.
	1 million	Current glass objects in the environment will be decomposed. Without maintenance, the Great Pyramid of Giza will erode into unrecognizability. On the Moon, Neil Armstrong's "one small step" footprint at Tranquility Base will erode by this time, along with those left by all twelve Apollo moonwalkers, due to the accumulated effects of space weathering. (Normal erosion processes active on Earth are not present due to the Moon's almost complete lack of atmosphere.)
	7.2 million
	100 million	Future archaeologists should be able to identify an "Urban Stratum" of fossilized great coastal cities, mostly through the remains of underground infrastructure such as building foundations and utility tunnels.

Astronomical events

Extremely rare astronomical events beginning in the 11th millennium AD (year 10,001) will be:

	Date / Years from now	Event
	20 August, AD 10,663	A simultaneous total solar eclipse and transit of Mercury.
	25 August, AD 11,268	A simultaneous total solar eclipse and transit of Mercury.
	28 February, AD 11,575	A simultaneous annular solar eclipse and transit of Mercury.
	17 September, AD 13,425	A near-simultaneous transit of Venus and Mercury.
	AD 13,727	The Earth's axial precession will have made Vega the northern pole star.
	13,000 years	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 the seasons in the Northern Hemisphere, which experiences more pronounced seasonal variation due to a higher percentage of land, will be even more extreme, as it will be facing towards the Sun at Earth's perihelion and away from the Sun at aphelion.
	5 April, AD 15,232	A simultaneous total solar eclipse and transit of Venus.
	20 April, AD 15,790	A simultaneous annular solar eclipse and transit of Mercury.
	14,000–17,000 years	The Earth's axial precession will make Canopus the South Star, but it will only be within 10° of the south celestial pole.
	AD 20,346	Thuban will be the northern pole star.
	AD 27,800	Polaris will again be the northern pole star.
	27,000 years	The eccentricity of Earth's orbit will reach a minimum, 0.00236 (it is now 0.01671).
	October, AD 38,172	A transit of Uranus from Neptune, the rarest of all planetary transits.
	26 July, AD 69,163	A simultaneous transit of Venus and Mercury.
	AD 70,000	Comet Hyakutake returns to the inner Solar System, after traveling in its orbit out to its aphelion 3,410 A.U. from the Sun and back.
	27 and 28 March, AD 224,508	Respectively, Venus and then Mercury will transit the Sun.
	AD 571,741	A simultaneous transit of Venus and the Earth as seen from Mars
	6 million	Comet C/1999 F1 (Catalina), one of the longest-period comets known, returns to the inner Solar System, after traveling in its orbit out to its aphelion 66,600 A.U. (1.05 light-years) from the Sun and back.

Calendar projections

This assumes that these calendars continue in use, without further adjustments.

	Years from now	Event
	10,000	—	The Gregorian calendar will have drifted by about 10 days in relation to the seasons.
	10 June, AD 12,892	In the Hebrew calendar, due to a gradual drift in relation to the solar year, Passover will fall on the northern summer solstice (it has historically fallen around the spring equinox).
	AD 20,874	The lunar Islamic calendar and the solar Gregorian calendar will share the same year number. After this, the shorter Islamic calendar will slowly overtake the Gregorian.
	25,000	—	The Tabular Islamic calendar will be roughly 10 days out of sync with the Moon's phases.
	1 March, AD 48,901	The Julian calendar (365.25 days) and Gregorian calendar (365.2425 days) will be one year apart. The Julian day number (a measure used by astronomers) at Greenwich mean midnight (start of day) is 19 581 842.5 for both dates.

Nuclear power

	Years from now	Event
	10,000	The Waste Isolation Pilot Plant, for nuclear weapons waste, is planned to be protected until this time, with a "Permanent Marker" system designed to warn off visitors through both multiple languages (the six UN languages and Navajo) and through pictograms. The Human Interference Task Force has provided the theoretical basis for United States plans for future nuclear semiotics.
	24,000	The Chernobyl Exclusion Zone, the 2,600-square-kilometre (1,000 sq mi) area of Ukraine and Belarus left deserted by the 1986 Chernobyl disaster, will return to normal levels of radiation.
	30,000	Estimated supply lifespan of fission-based breeder reactor reserves, using known sources, assuming 2009 world energy consumption.
	60,000	Estimated supply lifespan of fission-based light-water reactor reserves if it is possible to extract all the uranium from seawater, assuming 2009 world energy consumption.
	211,000	Half-life of technetium-99, the most important long-lived fission product in uranium-derived nuclear waste.
	250,000	The estimated minimum time at which the spent plutonium stored at New Mexico's Waste Isolation Pilot Plant will cease to be radiologically lethal to humans.
	15.7 million	Half-life of iodine-129, the most durable long-lived fission product in uranium-derived nuclear waste.
	60 million	Estimated supply lifespan of fusion power reserves if it is possible to extract all the lithium from seawater, assuming 1995 world energy consumption.
	5 billion	Estimated supply lifespan of fission-based breeder reactor reserves if it is possible to extract all the uranium from seawater, assuming 1983 world energy consumption.
	150 billion	Estimated supply lifespan of fusion power reserves if it is possible to extract all the deuterium from seawater, assuming 1995 world energy consumption.

Graphical timelines

For graphical, logarithmic timelines of these events see:

• Graphical timeline of the universe (to 8 billion years from now)
• Graphical timeline of the Stelliferous Era (to 10²⁰ years from now)
• Graphical timeline from Big Bang to Heat Death (to 10¹⁰⁰⁰ years from now)

See also

• Chronology of the universe
• Detailed logarithmic timeline
• Earth's location in the Universe
• Future of Earth
• Future of an expanding universe
• Heat death of the universe
• Human timeline
• Life timeline
• Nature timeline
• Orders of magnitude (time)
• Space and survival
• 10th millennium
• Timeline of cosmological epochs
• Timeline of natural history
• Timeline of the near future
• Ultimate fate of the universe

Bibliography

• Adams, Fred C. (2008). "Long term astrophysical processes". in Bostrom, Nick; Ćirković, Milan M.. Global catastrophic risks. Oxford University Press. ISBN 978-0-19-857050-9. https://books.google.com/books?id=-Jxc88RuJhgC&pg=PA33. 
• Brownlee, Donald E. (2010). "Planetary habitability on astronomical time scales". in Schrijver, Carolus J.; Siscoe, George L.. Heliophysics: Evolving Solar Activity and the Climates of Space and Earth. Cambridge University Press. ISBN 978-0-521-11294-9. https://books.google.com/books?id=M8NwTYEl0ngC&pg=PA79.