What Will Happen In One Billion Years?
If you could spend one day in the year 2100 to see what life would be like in that time, what do you think you would find? The idea of seeing the future - seeing life as we know it in a far, distant timescale - has been in the minds of people for thousands of years. What if you could see even further into the future? One thousand - ten thousand - a million - even a billion years into the future. What do you think the universe would look like? What events would occur in these vast timescales? What will we miss?
Let's start here on Earth. Everyone knows about Chernobyl, but if you don't, let's sum it up really quick. On April 26, 1986, just outside of the town of Pripyat, Ukraine, disaster struck at the Chernobyl nuclear power plant as Reactor No. 4 exploded, spewing over 8 tons of radioactive material into the surrounding area. This left the city almost completely uninhabitable. And due to the immense radiation still in the surrounding area, the Chernobyl zone won't be suitable for life until at least the year 22,000. By that time you and I will most likely be dead, so we won't be able to finally ride this Ferris wheel that we waited 20,000 years for.
In 50,000 years, due to lunar tides from the moon, the Earth's rotation will have slowed enough to the point that our days will become one second longer. If humans are still alive and thriving using our current timekeeping system, they will either need to add a leap second to the clock every single day (which let's be real would probably get really annoying really fast) or we would officially have to make the day one second longer. On a good night, you're able to walk outside and gaze up at the drops of milk in the sky.
And if you're good, you might be able to point out some constellations in specific stars. Except that in a hundred thousand years from today, Earth and our solar system will have traveled so far throughout the galaxies' orbit that the star patterns in the sky that you see today will look vastly different. But maybe you're just looking at the stars the wrong way. By this time, Mars should be able to be completely terraformed and you can hopefully take a look at the stars from a new planet. And it might be a good idea to get to Mars as soon as possible - for many reasons.
In 500,000 years, it is extremely likely the Earth will have been hit by an asteroid greater than one kilometer in diameter. This asteroid would most likely leave a crater over 400 kilometers wide and would cause massive fires across the globe rendering the air practically unbreathable. If that isn't enough for you to want to leave Earth, then perhaps this will change your mind.
In 1 million years, it is likely the Earth will have undergone a super volcanic eruption large enough to cover over 3,000 cubic kilometers with hot magma. This much magma could fill up about 75% of today's Grand Canyon. The last super volcanic eruption comparable to this event would most likely be the Toba Supereruption. This was so powerful that it single-handedly sent the world into a global volcanic winter for over ten years. Nearly all vegetation on Earth was destroyed, and scientists estimate that this single event almost completely wiped out human life. Numbers estimate that only 3,000-10,000 human individuals survived this eruption.
If you've been around on this channel long enough, you'll know that I made a video discussing the Kardashev Scale; the theoretical scale that ranks civilizations based on the amount of power they possess. It's estimated that in 1 million years, it's possible that - if humanity has survived and advanced enough - we could become a Type 3 civilization by the year 1 million. A Type 3 civilization harbors all of the power in the entire galaxy that it resides in - meaning that we could harness all of the energy of all the stars in the entire Milky Way Galaxy.
If humanity has thrived and successfully terraformed Mars, then this next milestone may be a problem. In 50 million years, it is believed that the orbit of Mars's moon Phobos will destabilize and come hurtling into the Martian atmosphere and inevitably be ripped apart by tidal forces. This destruction may result in Mars having a ring system much like Saturn does today, but those rings may not last forever. Saturn and its moons have quite the strong gravitational pull, so in about 100 million years, it's quite possible that all the rock and debris that formed Saturn's rings may be pulled in or ejected from the system leaving Saturn without its iconic rings.
In 240 million years, from our current position, our solar system will have completed about one entire orbit around the Milky Way's galactic center which is quite crazy to think about. For perspective, dinosaurs first stepped foot on the planet which was, at the time, a super-continent called Pangaea about 240 million years ago or, coincidentally, one in galactic orbit ago. Speaking of supercontinents, in 250 million years, all of Earth's land will most likely join together to become a brand-new super-continent: Pangaea Ultima. This is what scientists estimate the planet's continent will look like.
Pangaea Ultima is estimated to remain whole until the year 500 million during which, life on Earth may face another extinction event. When stars die, they explode their stellar guts across the universe in what is known as a supernova. Supernovae tend to eject insanely large beams of radiation known as Gamma-Ray Bursts or GRBs. Gamma-ray bursts are known to be some of the brightest and hottest events to occur in the entire universe. Our sun emits 3.86 x 10^26 watts of energy every second and has been doing so for the past 4.75 billion years. A gamma-ray burst emits more energy in 30 seconds than our Sun will emit in its entire 10 billion-year lifetime.
By the year 500 million, it's extremely likely that a GRB will occur within 6,500 light years of Earth and a gamma-ray burst from 6,500 light years away could destroy up to half of the Earth's ozone layer in one simple 30-second-long beam. On top of that, mass extinction amongst sea and land animals would ensue along with mass starvation.
And this is the start of the end for our dearly beloved Blue Marble: If there is still life on Earth in 800 million years, it ends now. At this point, CO2 levels on Earth will fall to a point where photosynthesis is no longer possible. Without photosynthesis, there is no more oxygen being made. No more oxygen, no more multicellular life. And thus, Earth is left as it was 4 billion years ago; a barren wasteland with no life whatsoever.
But there may be life on other planets by this time. In 1977, NASA launched two satellites - Voyager 1 and 2, on trajectories that will take them outside of our solar system - into interstellar space. Both satellites carried identical golden records. Each record is encased in a protective aluminum jacket together with a cartridge and needle for playing it. Instructions, in symbolic fashion, explain where the spacecraft came from in the solar system as well as instructions on how to play the record. The record contains 115 images from Earth along with greetings in 55 languages, sounds from Earth, and even music from the era when Voyager was launched.
And out of the 27 songs on the golden record, one of the most iconic and inspiring songs is Track 26 "Dark Was the Night" by Blind Willie Johnson. Johnson was diagnosed with a disability and blinded at a young age. His music sold very well, and he was fairly popular in his time, but despite this, he had very little wealth. His life was poorly documented and this is, in fact, the only known image of Blind Willie in himself.
But track 26 - "Dark Was the Night" - carries the weight of the entire human species on a long dark journey into the abyss of space. A man with very little to his name and not much knowledge of the world around him has his art traveling through the cosmos at a speed of over 17km/s. And I believe this elegantly depicts us humans. We are very curious creatures who yearn to explore the universe around us. We have very little knowledge of what is truly out there to be discovered. Much like Johnson, we are blind to what is outside our immediate vicinity.
The golden records on the Voyager crafts are us - humans. To any alien civilizations that may find the golden records, that is exactly what this image of Blind Willie Johnson is to us; a snapshot of who and what we are. Astronomer Carl Sagan was on the research team tasked with collecting a representation of Earth to put on the records and included Johnson's song because Johnson's song concerns the situation he faced many times: Nightfall with no place to sleep. Since humans appeared on Earth, the Shroud of Night has yet to fall without touching a man or woman in the same play.
The struggles of humanity in the form of music will be one of the first and last things alien civilizations may hear from us.