What If Earth Lost Its Atmosphere?
We’re alive on Earth thanks to a number of crucial features of this planet being just right. Our placement in the solar system’s habitable zone, the star-type of our sun and various fundamental, physical constants have all aligned to make our world like it is. One key component is our atmosphere but what would happen if it were to disappear?
Our atmosphere is responsible for regulating much of our planet’s natural processes. It allows us to breathe, have liquid water, and helps protect us against harmful UV radiation from the sun. Liquid water is one of the main ingredients needed for life, and one of the first things we look for when searching for other potentially habitable planets. Without an atmosphere, though, water in liquid form is unlikely to exist because surface temperatures could then swing between far-off and unmanageable extremes.
In this way, an atmosphere is what makes an environment at least a little bit predictable, and therefore survivable. Atmospheres generally form early on in a planet’s life, with our own developing billions of years ago. Naturally, however, they undergo changes over time, with some shifts more severe than others. The atmosphere of Mars, for example, has been all but stripped away completely by solar winds and radiation from the sun. Today, the remnant of the Martian atmosphere is incredibly weak – registering about 1% the total volume of Earth’s own. It’s thought that Mars once had flowing water in its ancient history, and some scientists suggest that it may even have hosted life at an early point in its existence but the loss of its atmosphere changed all of that.
Mercury is a similar case; because it’s so close to the sun, almost all of its atmosphere has been stripped away as well, leaving the planet at the mercy of the elements. When the surface of Mercury faces the sun it grows extremely hot, but when it faces away it’s thrown into freezing temperatures. There’s no atmospheric “regulator” there, making for wild and unstable conditions. Back on planet Earth, we are actually also losing our atmosphere just very slowly, and over a long period of time. But, in the hypothetical scenario that it was all to disappear at once, well, a lot would go wrong very quickly.
Earth is special. 🌎 It's the only place in the universe that we know contains life. Celebrate its beauty by taking a look at these breathtaking images of our home planet, as captured by crew members aboard the @Space_Station: https://t.co/hhtZE6w8n5 pic.twitter.com/8cLW7UdxnT
— NASA (@NASA) July 28, 2019
The most pressing concern would be that no-one would be able to breathe! Every creature that depended on oxygen for survival would instantly begin suffocating. It wouldn’t signal the end of life in general, though, with various bacteria and exceptionally hardy creatures – like the ruthlessly versatile tardigrade – able to survive even the vacuum of space which is what the surface of Earth will’ve now become! A disappearing atmosphere would be an almost inescapable death knell for human beings, though, unless they happened to be wearing a spacesuit at the time. Even were you to have somehow foreseen the end of the atmosphere and safely clothed yourself in full astronaut attire, however, the planet around you would now be an incredibly perilous place! The sky would suddenly go dark. Without atmospheric particles for light to scatter through, the usual blueness would disappear. All of the clouds would also vanish, as would the wind.