In part 3, humanity continued it’s colonization into the galaxy. Today, that colonization continues, with archaic technology performing massive feats, such as old NASA probes getting set to leave the Milky Way. While mankind, or “cosmosapiens”, discover and harness the wonders of the galaxy, the home they had for hundreds of thousands of years begins to succumb to it’s own wrath.
10,000 A.D.: The human race, having utilized the energy of their planets and their stars, become known as “Cosmosapien”, meaning wise ones of the stars. Earth’s axial precession makes Deneb the North Star. At this time is the estimated lifespan of the Long Now Foundation’s several ongoing projects. Also of note, according to Brandon Carter’s Doomsday agrument, which assumes that half of the humans who will ever live have already been born, human civilization will end. Also, on January 1, human technology could encounter the Year 10,000 Problem.
10,633 A.D.: Simultaneous total solar eclipse and transit of Mercury.
10,720 A.D.: Mercury and Venus will both cross the ecliptic at the same time.
11,268 A.D.: Simultaneous total solar eclipse and transit of Mercury.
11,575 A.D.: Simultaneous annular solar eclipse and transit of Mercury.
12,000 A.D.: The Gregorian Calendar will roughly be 10 day out of sync with the Sun’s position in the sky. Pioneer 10 passes within 3.8 light-years of Bernard’s Star.
13,425 A.D.: Near simultaneous transit of Venus and Mercury.
14,000-15,000 A.D.: The Earth’s axial precession makes Vega the North Star.
15,000 A.D.: By this point, halfway through the Earth’s precessional cycle, Earth’s axial tilt will be reversed, causing summer and winter to occur on opposite sides of the Earth’s orbit. This means that the seasons in the northern hemisphere, which experience a 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.
15,232 A.D.: Simultaneous total solar eclipse and transit of Venus.
15,790 A.D.: Simultaneous annular solar eclipse and transit of Mercury.
16,000-19,000 A.D.: The Earth’s axial precession will make Canopus the South Star, but it will only be within 10 degrees of the south celestial pole.
20,874 A.D.: The lunar Islamic Calendar and the solar Gregorian Calendar will share the same year number. After this, the shorter Islamic Calendar will overtake the Gregorian Calendar.
27,000 A.D.: The Arecibo message, a collection of radio data transmitted on November 16, 1974, reaches its destination, the globular cluster Messier 13. This is the only interstellar radio message sent to such a distant region of the galaxy. Assuming a similar mode of communication is employed, it would take at least as long again for any reply to reach Earth.
29,000 A.D.: The eccentricity of Earth’s will reach a minimum, 0.00236 (it’s now 0.01671).
30,000 A.D.: Sub-light ships are reaching the galactic center of the Milky Way.
38,000 A.D.: Ross 248, a small red dwarf star passes within 3.024 light-years of Earth, becoming the closest star to the Sun.
38,172 A.D.: Transit from Uranus from Neptune, the rarest of all planetary transits.
42,000 A.D.: Voyager 1 passes within 1.6 light-years of AC+79 3888, a star in the constellation Camelopardalis.
44,000 A.D.: Alpha Centauri becomes the nearest star system to the Sun once more as Ross 248 recedes.
48,901 A.D.: The Julian Calendar (365.25 days) and the Gregorian Calendar (365.2425 days) will be one year apart.
52,000 A.D.: If it is launched, the KEO Capsule reenters Earth, containing artifacts from the 21st Century. The current interglacial period ends, sending Earth back into Ice Age conditions, assuming the effects of anthropogenic global warming are limited. Niagra Falls erodes away the remaining 32 kilometers to Lake Erie, ceasing to exist. The length of the day used for astronomical timekeeping (based on the Julian Calendar) reaches about 86,401 SI seconds, due to lunar tides braking the Earth’s rotation, thus, under present-day timekeeping, a leap second will need to be added to the clock every day. Also of note, if a reply to the Aricebo message is sent from Messier 13, it will arrive at Earth at this time.
67,173 A.D.: Mercury and Venus will both cross the ecliptic at the same time.
69,163 A.D.: Simultaneous transit of Venus and Mercury.
100,000 A.D.: VY Canis Majoris, the largest known star in the Milky Way, explodes into a violent hypernova. The proper motion of stars across the celestial sphere, which is the result of their movement across the galaxy, renders many of the constellations unrecognizable. It is likely by this time, the Earth has seen a supervolcanic eruption large enough to erupt 400 km^3 (64,000,000 km) of magma.
224,508 A.D.: Respectively, Venus and then Mercury will transit the Sun.
250,000 A.D.: Lo’ihi, the youngest volcano in the Hawaiian-Emporer seamount chain, rises above the surface of the ocean and becomes a new volcanic island.
298,000 A.D.: Voyager 2 passes within 4.3 light-years of Sirius, the brightest star in the night sky.
302,000 A.D.: Pioneer 10 passes within 3 light-years of Ross 248.
500,000 A.D.: Earth will have likely been impacted by a meteorite of roughly 1 km in diameter, assuming it can’t be avoided.
571,741 A.D.: Simultaneous transit of Venus and the Earth, as seen from Mars.
1 million A.D.: Around this time, Earth will have likely seen a supervolcanic eruption large enough to erupt 3,200 km^3 (32.768 billion km) of magma. The event would be comparable to the Toba supereruption 75,000 years ago. This is also the highest estimated time until the red supergiant star Betelgeuse explodes into a supernova. The explosion is expected to have so much force and energy, it would be easily visible in daylight.