If we compressed the 13.8-billion-year-old history of the entire universe, beginning with the Big Bang up until now, into a single calendar year—“cosmic year 1” (CY-1, for short)—when would we appear on the scene? At late as 11:53 p.m., on December 31 of CY-1. The dinosaurs went extinct at 6:25 a.m., on December 30.
Continuing on with this scale, what does the future look like?
The constellations we’re familiar with will all be unrecognizable by 12:02 a.m. of CY-2. Minutes later, we’re likely to enter the next Ice Age.
The Sun will continue to get hotter as it ages, boiling our oceans away, and ending life on Earth as we know it, in about 1 to 2 billion years, or on February 8, CY-2.
Over the next 3 to 5 billion years, the Andromeda galaxy will merge with our own Milky Way, causing a spectacular change in the night sky. Presently at a distance of 2.5 million light-years away, but moving towards us at the speed of a slow-moving car, it’s predicted to collide with our home galaxy, leading to a burst of star formation, in 3.8 billion years , or on April 10, CY-2.
About 5 to 7 billion years down the line, or around June 8, CY-2, the Sun’s core will run out of nuclear fuel, causing it to become a red giant, gobbling up Mercury and Venus in the process.
The Earth and Moon will likely be jostled away and be spared the fiery fate of our inner neighbors.
The Sun will shrink to a white dwarf. The planets will still be around, orbiting our cold, dim, stellar remnant. This process will complete around 9.5 billion years from now, or on September 8, CY-2.
50 billion years out, the Moon’s speed of rotation will have slowed down such that it’ll take 47 days (as compared to the present 27.3 days) to spin once on its axis. Earth too, would’ve decelerated its speed of rotation, and a “day” would have lengthened to 47 days.
At this point, the Moon and Earth will always appear in the same position in one another’s skies. This will come to pass on August 14, CY-5.
10^16 years ahead, as the now-white dwarf cools, it’ll morph into a black dwarf. The sky would turn into a starless, pitch-black expanse. This won’t happen until CY-724,000.
After around CY-10^21, the now-black dwarf at the center of our solar system will ram into another black dwarf, producing a supernova explosion, and wipe what’s left of the solar system. That will take place around CY-100 billion—a timescale we can’t even begin to conceive.
h/t: STARTS WITH A BANG