10,000-15,000 AD
The hypernova of Eta Carinae is affecting our region of the galaxy
Eta Carinae is among the largest, most volatile stars in our galaxy. Its temperature is so high that it is unable to hold onto its own gas, with constant streams being ejected from the surface. It first came to attention in 1843 when it flared to magnitude -0.8, becoming the second brightest star in the night sky.
Eta Carinae is among the largest, most volatile stars in our galaxy. Its temperature is so high that it is unable to hold onto its own gas, with constant streams being ejected from the surface. It first came to attention in 1843 when it flared to magnitude -0.8, becoming the second brightest star in the night sky.
It subsequently died down, before brightening again in the late 1990s. This fluctuation continues – with periodic flaring and dimming – until one day the inevitable happens. Unable to maintain its cohesion, Eta Carinae erupts into one of the deadliest known forces in nature: a hypernova.
For a brief period, this colossal explosion outshines the entire galaxy. It is bright enough to be visible during daytime on Earth, while at night, it is similar to the full moon.*
Of much greater concern, however, are the lethal jets of gamma radiation released by the dying star. These begin to shoot outward, at such high energies that even systems thousands of light years away are affected. As a result, numerous planets in our region of the galaxy undergo mass extinctions during this time.*
Our Sun is exiting the Local Interstellar Cloud
The Local Interstellar Cloud (also known as the "Local Fluff") is a cloud of neutral hydrogen 30 light years across and flowing outwards from the Scorpius-Centaurus Association, a nearby star-forming region. The Solar System is thought to have entered the Local Interstellar Cloud sometime between 150,000 BC and 42,000 BC. Its density is about six times greater than the Local Bubble – a much larger region measuring 300 light years in diameter that surrounds both it and the G-Cloud, another cloud of gas.
The Local Interstellar Cloud (also known as the "Local Fluff") is a cloud of neutral hydrogen 30 light years across and flowing outwards from the Scorpius-Centaurus Association, a nearby star-forming region. The Solar System is thought to have entered the Local Interstellar Cloud sometime between 150,000 BC and 42,000 BC. Its density is about six times greater than the Local Bubble – a much larger region measuring 300 light years in diameter that surrounds both it and the G-Cloud, another cloud of gas.
In 2009, Voyager 2 data suggested that the magnetic strength of the local interstellar medium was much stronger than previously expected (3.7 to 5.5 μG, against previous estimates of 1.8 to 2.5 μG). The fact that the Local Interstellar Cloud is strongly magnetised was said to explain its continued existence, despite the pressures exerted upon it by the winds that blew out the Local Bubble. Its potential effects on Earth were prevented by the solar wind and the Sun's magnetic field.
By 12,000 AD, our Sun has exited the Local Interstellar Cloud and is heading towards the neighbouring G-Cloud, which contains the stars Alpha Centauri, Proxima Centauri and Altair.*
Betelgeuse is colliding with a dusty wall
Betelgeuse is the nearest red supergiant star to Earth. It can be seen with the naked eye in the northern hemisphere winter night sky as the orange-red star above and to the left of Orion's famous three-star belt.Roughly 1,000 times the diameter and 100,000 times the brightness of the Sun, Betelgeuse is on its way to becoming a supernova, having already swelled in size and shed a significant fraction of its outer layers.
Betelgeuse is the nearest red supergiant star to Earth. It can be seen with the naked eye in the northern hemisphere winter night sky as the orange-red star above and to the left of Orion's famous three-star belt.Roughly 1,000 times the diameter and 100,000 times the brightness of the Sun, Betelgeuse is on its way to becoming a supernova, having already swelled in size and shed a significant fraction of its outer layers.
The star's winds are crashing against the surrounding interstellar medium, producing a curved "bow shock" as the star moves through space at 30 km/s. A series of broken, dusty arcs ahead of the star's direction of motion testify to a turbulent history of mass loss.
In the early 21st century, the Herschel Space Observatory found a mysterious wall-like structure in far-infrared. It was seen further away from the star, beyond the dusty arcs, its linear shape indicating that it was completely separate from and unrelated to Betelgeuse. It was, however, being illuminated by the supergiant. Astronomers of the time believed it was either a linear filament linked to the Galaxy's magnetic field, or the edge of a nearby interstellar cloud.
In 7000 AD, a collision occurs between the wall and the bow shock zone. This is followed by a collision between the wall and Betelgeuse itself, some 12,500 years later.*
The Chernobyl disaster site becomes fully safe
The Chernobyl explosion, which occurred in 1986, was the worst nuclear accident in history – affecting tens of thousands of square kilometres of land. Radiation at the centre of the former disaster zone has decayed to negligible levels by now.*
The first wave of sub-light vessels has reached the galactic core
The core region is located 27-28,000 light years from Earth. At its centre lies the largest black hole in the galaxy – a supermassive black hole.* Having travelled for many millennia, the first wave of sub-light spacecraft has now arrived in its vicinity.
The core region is located 27-28,000 light years from Earth. At its centre lies the largest black hole in the galaxy – a supermassive black hole.* Having travelled for many millennia, the first wave of sub-light spacecraft has now arrived in its vicinity.
These ships contain no physical human crew, being entirely computerised and automated. Numbering in the trillions, they have self-replicated along the way, using local stellar and planetary material gathered en route.*Systems encountered during this epic voyage have become seeded with computational substrates and saturated with artificial intelligence – individual planets and moons becoming like brain cells in a gigantic, artificial organism. It is almost as though the galaxy itself is waking up and achieving self-awareness.*
There is no competition or battle to claim ownership of the core. Wars, greed and archaic concepts of nationality have long since disappeared, with sentient beings now united under a common heritage.
In addition to the black hole, there are dense concentrations of ancient, metal-rich stars; in places separated by only a few light weeks or light days. These provide an enormous pool of resources for the approaching fleets.
Gamma radiation is so high in this region that almost nothing biological can survive, except for the hardiest of extremophile bacteria. Were an observer able to stand on a planet near the core, the sky above them would appear as a dazzling display of light and colour.
Having reached the galactic centre, efforts are now underway to explore the far side of the galaxy and the mysteries that lie beyond. Dozens of globular clusters have also been reached by now.*
Ross 248 becomes the closest star to our Sun
Alpha Centauri was previously the closest star. Ross 248 is a red dwarf, with approximately 12% of the Sun's mass and 16% of the Sun's radius, but only 0.2% of its luminosity. However – it is also a "flare star", that periodically undergoes sudden, dramatic increases in brightness for a few minutes.
Alpha Centauri was previously the closest star. Ross 248 is a red dwarf, with approximately 12% of the Sun's mass and 16% of the Sun's radius, but only 0.2% of its luminosity. However – it is also a "flare star", that periodically undergoes sudden, dramatic increases in brightness for a few minutes.
In 2010, Ross 248 was 10.3 light years from Earth, with a radial velocity of -81 km/s. By 35,000 AD, it is closer than Alpha Centauri. It reaches its closest point in 38,000 AD – moving to within 3.1 light years – before receding again, becoming further from the Sun than Alpha Centauri in 44,000 AD.
Voyager 1 is passing near the red dwarf star, AC+79 3888
Launched by NASA in 1977, the Voyager I space probe continues to drift through interstellar space. It is now passing near AC+79 3888, an M-type main sequence star in the constellation of Camelopardalis, close to Polaris.*Its sister probe, Voyager 2, will reach Sirius in approximately 298,000 AD.
Launched by NASA in 1977, the Voyager I space probe continues to drift through interstellar space. It is now passing near AC+79 3888, an M-type main sequence star in the constellation of Camelopardalis, close to Polaris.*Its sister probe, Voyager 2, will reach Sirius in approximately 298,000 AD.
The KEO time capsule re-enters the Earth's atmosphere*
KEO was a time capsule launched in 2012 and intended to orbit Earth for 50,000 years – the same length of time that had elapsed since early humans began drawing in cave walls.
KEO was a time capsule launched in 2012 and intended to orbit Earth for 50,000 years – the same length of time that had elapsed since early humans began drawing in cave walls.
The project was supported by the UN Educational, Scientific and Cultural Organization (UNESCO), as well as the European Space Agency (ESA) and other institutions.
The public were invited to contribute messages.* These were encoded in glass-made, radiation-resistant DVDs, along with instructions to future generations on how to build a DVD reader. Samples of human blood, earth, air and seawater were also placed on board.
The capsule itself is a hollow sphere, 80cm in diameter. The sphere is engraved with a map of Earth and surrounded by an aluminium layer, a thermal layer and several layers of titanium, intertwined with vacuum. The sphere is resistant to cosmic radiation, atmospheric re-entry and space junk impacts.
Placed into orbit 1,800 km high, the satellite's altitude has slowly degraded by a few dozen metres each year. As it finally re-enters the atmosphere, its thermal layer produces a bright, artificial aurora to signal its return.
100,000 AD
The red hypergiant star, VY Canis Majoris, has exploded by now, producing one of the largest supernovas the galaxy has ever seen*
VY Canis Majoris, at between 1800 and 2100 times bigger than our Sun (8.4–9.8 au, 2.7 billion km or 1.7 billion miles in radius), is the largest known star in the Milky Way, and also one of the brightest known. It is located around 4,900 light years from Earth, in the constellation Canis Major. It was discovered to be very unstable, throwing off much of its mass into the surrounding nebula. By 100,000 it has finally exploded, creating a supernova bright enough to be seen during daylight hours on Earth.
VY Canis Majoris, at between 1800 and 2100 times bigger than our Sun (8.4–9.8 au, 2.7 billion km or 1.7 billion miles in radius), is the largest known star in the Milky Way, and also one of the brightest known. It is located around 4,900 light years from Earth, in the constellation Canis Major. It was discovered to be very unstable, throwing off much of its mass into the surrounding nebula. By 100,000 it has finally exploded, creating a supernova bright enough to be seen during daylight hours on Earth.
Constellations visible from Earth have been rendered unrecognisable
Proper motion – the continuous movement of celestial bodies due to changing orbits or the remaining effects of the Big Bang – has radically changed the view of the night sky from Earth. Stars naturally move at different velocities, depending on the manner in which a star formed from its original dust cloud. By 50,000 AD, constellations were beginning to be twisted and bent into new shapes* and by 200,000 AD have become completely unrecognisable.* This includes once famous groups of stars like the Big Dipper, Orion, Ursa Major, Perseus and Gemini. As a result of changes in Earth's axial orientation, Gamma Cephei, Iota Cephei and Vega have taken the position of the North Star.
Proper motion – the continuous movement of celestial bodies due to changing orbits or the remaining effects of the Big Bang – has radically changed the view of the night sky from Earth. Stars naturally move at different velocities, depending on the manner in which a star formed from its original dust cloud. By 50,000 AD, constellations were beginning to be twisted and bent into new shapes* and by 200,000 AD have become completely unrecognisable.* This includes once famous groups of stars like the Big Dipper, Orion, Ursa Major, Perseus and Gemini. As a result of changes in Earth's axial orientation, Gamma Cephei, Iota Cephei and Vega have taken the position of the North Star.
Voyager 2 is approaching Sirius
Voyager 2 was an unmanned space probe launched in 1977 to investigate the outer planets of the solar system. Identical in form and function with its sister craft, Voyager 1, it was launched on a slower, more curved trajectory that allowed it to be kept in the plane of the Ecliptic. This enabled it to be sent on to Uranus and Neptune by means of utilising gravity assists during its fly-by of Saturn in 1981 and of Uranus in 1986.
Voyager 2 was an unmanned space probe launched in 1977 to investigate the outer planets of the solar system. Identical in form and function with its sister craft, Voyager 1, it was launched on a slower, more curved trajectory that allowed it to be kept in the plane of the Ecliptic. This enabled it to be sent on to Uranus and Neptune by means of utilising gravity assists during its fly-by of Saturn in 1981 and of Uranus in 1986.
By 2010, Voyager 2 was around 92 AU (13.75 billion km, 8.5 billion miles, or 0.001443 ly) from the Sun, deep in the scattered disc, and traveling outward at roughly 3.26 AU per year.
The probe survives for thousands of years in the emptiness of interstellar space. It eventually passes by Sirius, having covered a distance of over 25 trillion miles.* Sirius is the brightest star in the sky when viewed from Earth.
Planet-sized computers are dominating the Local Group of galaxies; humanity's descendants are a Type 3 civilisation on the Kardashev scale
Purely biological (non-cyborg) humans are exceedingly rare now. The very few which do remain comprise only a tiny fraction of the total sentient minds in existence. Though free to come and go as they please, they have practically zero influence in any governmental systems on Earth or elsewhere, being regarded as wholly subordinate to AIs and other entities. As a species, homo sapiens has continued to evolve over time. This has led to a further increase in cranial size, a near-total absence of hair, an elongation of limbs, a more robust and capable immune system, and increased lifespan.
Purely biological (non-cyborg) humans are exceedingly rare now. The very few which do remain comprise only a tiny fraction of the total sentient minds in existence. Though free to come and go as they please, they have practically zero influence in any governmental systems on Earth or elsewhere, being regarded as wholly subordinate to AIs and other entities. As a species, homo sapiens has continued to evolve over time. This has led to a further increase in cranial size, a near-total absence of hair, an elongation of limbs, a more robust and capable immune system, and increased lifespan.
The vast majority of humans have long since abandoned these primitive biological forms, making the transition to machines or other substrates and achieving practical immortality. The entire Milky Way galaxy has been explored by these transhumans and their sentient ships.
Faster-than-light travel is now possible using Alcubierre drives, which are compact and miniaturised enough to be found in even personal, single-occupancy vessels. These use such colossal amounts of power that they cause the fabric of space ahead of a ship to contract, while the space behind it expands. This bypasses the laws of relativity, allowing travel to even neighbouring galaxies such as M31 (Andromeda) and M33 (Triangulum).
Planet-sized computers are being constructed throughout the Local Group of galaxies, with every available resource going towards their production. All of the "dead" worlds, comets, moons and asteroids considered uninhabitable are being converted into these machines, forming a vast network millions of light years across space. Each computer is capable of instant communications with any other, regardless of distance.
A number of alien intelligences have been contacted by now. In addition, ancient ruins have been uncovered on some worlds, indicating advanced civilisations that somehow failed or destroyed themselves in the distant past. Thousands of other planets have been discovered to have rich ecosystems, brimming with diverse plant and animal (and other) life. Most of the fauna being catalogued is small and insect-like, but some is more developed with intelligence comparable to higher mammals such as dolphins, monkeys and cats.
The few biological (non-cyborg) humans that remain are avoiding the core regions in each galaxy, which are filled with extremely high concentrations of gamma radiation, blackholes and other hazards – dangerous even with the technologies and protections of today.
1,400,000 AD
The Oort cloud is being disrupted by the approach of Gliese 710
The orange dwarf star, Gliese 710, is passing within 1.1 light years (70,000 AU) of the Sun. This is close enough to disrupt the Oort Cloud surrounding our solar system. A shower of comets is now heading in-system.
At its closest approach, Gliese 710 will be a first-magnitude star when viewed from Earth: one of the brightest in the night sky.
Pioneer 10 is approaching the Aldebaran system
Pioneer 10 was the first space probe to travel through the asteroid belt and to directly observe Jupiter, which it passed by in 1973. After completing its mission, it began heading in the direction of Aldebaran – a red giant star located 65 light years away in the constellation Taurus.
Pioneer 10 was the first space probe to travel through the asteroid belt and to directly observe Jupiter, which it passed by in 1973. After completing its mission, it began heading in the direction of Aldebaran – a red giant star located 65 light years away in the constellation Taurus.
The final contact with the probe was made in 2003, when a very weak signal was detected from the craft, 12 billion kilometers (7.5 billion miles) from Earth. An attempt at contact in 2006 was unsuccessful.
After travelling at roughly 2.6 AU per year, Pioneer 10 begins to approach the Aldebaran system in 2,000,000 AD.*
Attached to the probe is a pictorial message, in case of interception by extraterrestrial life. This plaque shows the nude figures of a human male and female, along with symbols that are designed to provide information about the origin of the spacecraft.
Pioneer 11 is approaching the Lambda Aquilae system
Pioneer 11 is the sister craft of Pioneer 10. Launched in 1973, it completed a successful flyby of Saturn in 1979, before heading out to interstellar space, travelling in the opposite direction of Pioneer 10. After four million years, it passes by Lambda Aquilae, a blue-white B-type main sequence dwarf star, around 125 light years from Earth.*Like its sister, Pioneer 11 carries a plaque with a message from humankind.
Pioneer 11 is the sister craft of Pioneer 10. Launched in 1973, it completed a successful flyby of Saturn in 1979, before heading out to interstellar space, travelling in the opposite direction of Pioneer 10. After four million years, it passes by Lambda Aquilae, a blue-white B-type main sequence dwarf star, around 125 light years from Earth.*Like its sister, Pioneer 11 carries a plaque with a message from humankind.
6,800,000 AD
DNA from the 21st century has completely decayed
Even if preserved under ideal storage conditions of −5°C, every molecular bond in a strand of DNA will decay after 6.8 million years. Any remaining biological samples from the 21st century which have not been recovered or digitised are now completely destroyed.*
7,200,000 AD
Mount Rushmore has eroded away
Absent human intervention, the famous faces of Presidents carved in the side of this rock formation have disappeared by now. Granite has an erosion rate of approximately one inch per 10,000 years.*
7,600,000 AD
Phobos is ripped apart by Mars' gravity
Phobos is the largest and closest of the two moons of Mars. Because its orbital period is shorter than a Martian day, tidal deceleration has been decreasing its orbital radius at the rate of about 20 metres (66 ft) per century.
By this date, it has passed the Roche limit – the distance within which a celestial body, held together only by its own gravity, will disintegrate due to a second body's tidal forces exceeding the first's gravitational self-attraction.
Phobos begins to break apart. It gradually becomes a ring system over the following 3 million years, with many of these fragments impacting upon Mars itself.*
8,400,000 AD
LAGEOS-1 returns to Earth
Laser Geodynamics Satellites (LAGEOS) were a pair of scientific research satellites launched in the late 20th century and designed to provide an orbiting laser ranging benchmark for geodynamical studies. Each was a high density passive laser reflector in a very stable medium Earth orbit (MEO), roughly 5,900 kilometres (3,700 mi) in altitude.
These spacecraft were aluminium-covered brass spheres with diameters of 60cm and weighing approximately 400kg, covered with cube-corner retroreflectors, giving them the appearance of giant golf balls. They had no on-board sensors or electronics, and no attitude control. Measurements were made by transmitting pulsed laser beams from ground stations to the satellites. The laser beams returned to Earth after hitting the reflecting surfaces.
Due to the stability of their orbits, the LAGEOS satellites made it possible to determine positions on the Earth with ultra-high accuracy: better than one inch in thousands of miles. At the time, this made them the most precise location references available. As such, they were used for monitoring the movement of the Earth's tectonic plates, gravitational field, the "wobble" in its axis of rotation, and for determining the exact length of an Earth day.
However, these satellites would fall back to Earth eventually. LAGEOS-1 was predicted to re-enter the atmosphere in 8,400,000 AD. It contained a plaque, designed to allow future descendants of humans to view the arrangement of Earth's continents in the past, present and future.*
10,000,000 AD
Earth is being threatened by lethal levels of gamma radiation
T Pyxidis is a binary star system in the constellation Pyxis. It contains a sun-like star and a white dwarf. Because of the strong gravitational effect of the white dwarf, it draws matter from the other star which causes periodic thermonuclear explosions (so-called novae) to occur.
Around this time, it reaches the so-called Chandrasekhar Limit, causing it to undergo an instantaneous collapse that completely destroys the star in a Type 1a supernova. This catastrophic event releases 10 million times more energy than a typical nova explosion – the equivalent of 20 billion, billion, billion megatons of TNT.*
The system is only 3,260 light years away, close enough to destroy Earth's ozone layer and cause mass extinctions unless the planet is shielded by advanced technology.
Triton’s decaying orbit has led to it breaking up around Neptune, forming a new ring system
That's assuming the moon still exists in a form we would recognise. The descendants of humanity may have converted its raw mass into artificial structures by now. Even Neptune itself may no longer exist – the planet’s hydrogen and helium may have been siphoned off for use in starships and industrial processes.
27,000,000 AD
Smith's Cloud is colliding and merging with our Milky Way galaxy
Smith's Cloud is a high-velocity cloud of hydrogen gas, around 9,800 light years long and moving on a direct collision course with the Milky Way. It was first discovered in 1963 and measurements showed it to be roughly 40,000 light years from Earth, lying outside the galactic plane.
This immense cloud was found to be moving at 150 miles/s (240 km/s),* approaching at a 45° angle and predicted to reach the galactic plane in 27 million AD. By this date,* it has collided and begun merging with part of the Perseus Arm – one of two major spiral arms of the Milky Way.
The impact generates shockwaves creating an intense burst of star formation in that part of the galaxy, like a slow-motion firework display. Over a million new stars are formed – many ending up as supernovae within a relatively short time and exploding with a billion times the brightness of our Sun.*
30,000,000 - 40,000,000 AD
At some point during this period, an asteroid 10-20 km in size comes on a direct collision course with Earth
Impacts of this size tend to happen every 100 million years or so.* The last such event occurred 65m years ago – resulting in the extinction of the dinosaurs.
If humanity or its descendants are no longer around to protect it, any remaining life on the planet may be in danger of a similar mass extinction during this time.
An impact of this scale would release around 4×1023 joules of energy, equivalent to 100 million megatons of TNT. By contrast, the most powerful man-made explosion in history, the "Tsar Bomba", had a yield of only 50 megatons.
If landing in the ocean, it would produce megatsunamis reaching thousands of feet high. A cloud of super-heated dust, ash and steam would spread from the crater, as the impactor burrowed underground in less than a second. Excavated material and pieces of the impactor – ejected out of the atmosphere by the blast – would be heated to incandescence upon re-entry, broiling the Earth's surface and igniting global wildfires. Meanwhile, colossal shock waves would spawn global earthquakes and volcanic eruptions. The emission of dust and particles would cover the entire surface of the Earth for several years, possibly a decade, creating a harsh environment for living things to survive. The shock production of carbon dioxide caused by the destruction of carbonate rocks would trigger a sudden greenhouse effect.
Over a longer period of time, sunlight would be blocked from reaching the surface of the earth by the dust particles in the atmosphere, cooling the surface dramatically. Photosynthesis by plants would be interrupted, collapsing the entire food chain.
50,000,000 AD
The African continent merges with Europe, forming a new mountain range to rival the Himalayas
The Mediterranean no longer exists. The Red Sea, Black Sea and Caspian Sea have also disappeared. Meanwhile, the Atlantic Ocean has continued to widen, and southeast Asia is merging with Australia.
100,000,000 AD
The Milky Way galaxy has stabilised from an earlier collision
Our galaxy is surrounded by dozens of smaller dwarf galaxies. These will occasionally pass through the disk of the Milky Way, disrupting both it and the incoming satellite. One such collision occurred in approximately 100 million BC. This was confirmed by observations of 300,000 nearby stars, whose motions indicated a reverberation or "ringing" like a bell. The stars were found to be moving up and down at speeds of 20-30 kilometres per second while orbiting the centre of the galaxy at 220 kilometres per second.
It would take a further 100 million years (from the time of this observation) for this motion to stabilise and for the Milky Way to stop reverberating. By now, the north-south asymmetry has disappeared and the vertical motions of stars in the solar neighborhood have reverted back to their equilibrium orbits.*
150,000,000 AD
The Atlantic Ocean begins to close
The mid-Atlantic ridge is causing the Americas and Africa to begin moving back together. Australia has become fully merged with Indonesia and Antarctica.
225,000,000 AD
Sol completes one galactic year
By now, our Sun has completed another clockwise revolution around the galaxy – the 21st in its lifetime so far.
The Sun's orbit is roughly elliptical, with perturbations due to the galactic spiral arms and non-uniform mass distributions. In addition, the Sun oscillates up and down relative to the galactic plane, around 2.7 times per orbit.
The Sun's passage through the higher density spiral arms has coincided with mass extinctions on Earth, due to increased impact events.
The orbital speed of the Solar System around the center of the Galaxy is approximately 251 km/s.
250,000,000 AD
A supercontinent is forming on Earth
The next Pangea – Pangea Ultima – is forming, with all of the major continents moving back together, surrounding a small ocean basin.
Our Sun is becoming noticeably hotter and brighter, raising global temperatures by several degrees. Much of Earth is now covered by deserts.
600,000,000 AD
Total solar eclipses are no longer possible on Earth
Due to tidal acceleration, the distance of the Moon from the Earth has been increasing by approximately 3.8cm each year. By 600 million AD, the distance has increased by nearly 23,000 km. At the same time, the Sun has been growing in size by a significant amount.
As a result, the Moon is no longer big enough in the sky to completely cover the Sun's disk, making total eclipses impossible. This is true even when the Moon is at perigee and the Earth is at aphelion.
The reduced gravitational influence of the Moon is affecting Earth's oceans – with smaller waves and less variation in tide heights.
750,000,000 AD
The Sagittarius dwarf galaxy has been absorbed into the larger Milky Way
The Sagittarius dwarf elliptical galaxy (Sag DEG) is a tiny satellite galaxy orbiting the Milky Way. For aeons, it has been stretched and torn apart by the immense tidal forces of its neighbour. By now, it has been completely absorbed into the Milky Way.*
When first discovered, astronomers thought that Sag DEG had already reached an advanced stage of destruction. However, later observations showed that it still had coherence, as a dispersed elongated ellipse. It appeared to be moving in a roughly polar orbit around the Milky Way, reaching as close as 50,000 light years from the galactic core. Computer simulations indicated that stars ripped out from the dwarf would be spread out in a vast "stellar stream" along its path, and these were subsequently confirmed.
Sag DEG may have orbited the Milky Way as many as ten times, prior to being swallowed up. Its ability to retain some coherence, despite such strains, would indicate an unusually high level of dark matter in that galaxy.
1,000,000,000 AD
Earth is becoming too hot to support liquid water
The Sun's luminosity has increased by 10%, causing Earth's surface temperatures to reach an average of 47°C (116°F).* As the seas and oceans begin to evaporate, the atmosphere is becoming laden with water vapour, creating an intense greenhouse effect. Mars is actually becoming more habitable during this time.*
The Sun's luminosity has increased by 10%, causing Earth's surface temperatures to reach an average of 47°C (116°F).* As the seas and oceans begin to evaporate, the atmosphere is becoming laden with water vapour, creating an intense greenhouse effect. Mars is actually becoming more habitable during this time.*
3,800,000,000 AD
The Andromeda Galaxy has begun to collide and merge with our own Milky Way galaxy
The earliest recorded observation of Andromeda – the nearest spiral galaxy to our own – was made in the year 964. Persian astronomer, Abd al-Rahman al-Sufi, described the object as a "small cloud". The first description based on telescopic observation was given by German astronomer Simon Marius in 1612. Charles Messier catalogued it as M31 in 1764 and incorrectly credited Marius as the discoverer, unaware of Al Sufi's earlier work. The first photographs were taken in 1887 by Isaac Roberts, and the first radio maps were produced in the 1950s by John Baldwin.
Later observations confirmed the size, distance and velocity of Andromeda. It was found to be the largest galaxy in the Local Group, with over a trillion stars – at least twice as many as the Milky Way. It was 2.5 million light years from Earth and moving at 250,000 miles per hour. It was also found to be on a collision course: heading directly towards the Milky Way.
By 3,800,000,000 AD, a full-scale merger is underway.** A single, giant elliptical galaxy will eventually be formed. Stars and planets within each galaxy almost never collide, however, as galaxies are extremely diffuse. Such mergers are in fact relatively common. Andromeda, for example, collided with at least one other galaxy in the distant past.
5,000,000,000 AD
Sol is a red giant
The inner planets of the solar system have been destroyed and absorbed by the ballooning Sun. Its radius has now expanded by over 200 times.
12,000,000,000 AD
Sol is shrinking to become a black dwarf
Most of the Sun's mass has been ejected, forming a planetary nebula. Having ended its main sequence life, it now begins to cool and dim – changing from a dense white dwarf into a cold, inactive black dwarf.
100,000,000,000 AD
The Virgo Supercluster is converging into a single galaxy
The Virgo Supercluster – containing hundreds of smaller clusters including our own – is now so ancient that it has begun to stabilise and converge into a single huge galaxy, many millions of light years across.
Other superclusters are also converging, but are now separated from each other by billions of light years due to the acceleration of dark energy.
1,000,000,000,000 AD
A significant percentage of galaxies are beginning to "burn out", having been depleted of the gas clouds required to form stars.
2,000,000,000,000 AD
Dark energy has continued to drive the expansion of the universe at an ever-accelerating rate. By now, the volume of the universe is so great – and the speed of acceleration so high – that everything beyond the Local Supercluster is no longer visible.
Even for the highest energy gamma rays, a redshift of 1053 means their wavelength is stretched to greater than the physical diameter of the horizon.
Because of this, any remaining intelligent life today may no longer be able to obtain new empirical data on the state of large-scale structures on scales observed in the past.
20,000,000,000,000 AD
By now, even some of the longest-lived stars in our galaxy – such as red dwarfs – have begun to fade away, leaving behind only cold "black dwarfs" emitting trace amounts of radiation. This includes once famous stars such as Proxima Centauri, Barnard's Star and Wolf 359. The Milky Way galaxy is becoming a dark, empty place dominated by enormous blackholes.
100,000,000,000,000 AD
The last of the main sequence stars in our universe has withered away to nothing. The only stellar-mass objects now remaining are white dwarfs, neutron stars and black holes. Brown dwarfs also remain.
Planets everywhere have been dislodged from their previous orbits and left drifting as "rogues", with many ending up in black holes.
10,000,000,000,000,000,000,000,000,000,000,000,000 AD
In this era, the only energy being generated in the universe is through proton decay and particle annihilation. Neutron stars, white dwarfs and black holes are now the only remaining objects. Due to extreme age, all of the planets and moons have disintegrated and decayed into their constituent atomic particles, or else been absorbed into stellar remnants.
10,000,000,000,000,000,000,000,000,000,000,000,000,
000,000,000,000,000,000,000,000,000,000,000,000,000,
000,000,000,000,000,000,000,000 AD
Only black holes and subatomic particles remain. The universe has expanded so much that these individual particles may be separated from each other by truly enormous distances. Black holes themselves are now evaporating by Hawking radiation.
Beyond 10100
The last remaining black hole has evaporated.
From this point onwards the universe is composed only of photons, neutrinos, electrons and positrons – with no way of interacting with each other.
The universe continues to expand forever... but is essentially dead.
References
Accessed 14th November 2009.
2 It is unlikely that Earth would be affected. Even if the gamma ray jets point in our direction, the solar system will likely be protected by a Dyson shell (or similar giant structure) by then. Less developed colonies in other star systems might not be so fortunate, however.
3 "Our Sun may exit the Local Cloud, also called the Local Fluff, during the next 10,000 years." See Astronomy Picture of the Day, NASA:
http://apod.nasa.gov/apod/ap130924.html
Accessed 19th January 2014.
4 "...the outermost arc will collide with the bar in just 5000 years, with the red supergiant star itself hitting the bar roughly 12,500 years later." See Betelgeuse Braces for a Collision: Red Supergiant Star to Crash Into Dusty 'Wall', Science Daily:
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Accessed 24th January 2013.
5 "There is a 17 mile Exclusion Zone around Chernobyl where officially nobody is allowed to live, but people do. These "resettlers" are elderly people who lived in the region prior to the disaster. Today there are approximately 10,000 people between the ages of 60 and 90 living within the Zone around Chernobyl. Younger families are allowed to visit, but only for brief periods of time.
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Accessed 12th February 2011.
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Accessed 12th February 2011.
http://www.kurzweilai.net/the-technology-of-universal-intelligence
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Accessed 12th February 2011.
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Accessed 29th October 2010.
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Accessed 23rd January 2011.
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http://news.bbc.co.uk/1/hi/7184521.stm
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Accessed 28th September 2010.
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31 This is discounting the possibility that it may already have been terraformed. See 2500 AD.
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http://www.popsci.com/science/article/2012-05/video-simulated-look-milky-way-and-andromeda-galaxy-colliding Accessed 1st June 2012.
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Accessed 22nd May 2009.
