How Long Can A Human Survive In Space?
There's a reason astronauts use space suits, and that reason is simple: Given half a chance, space will kill you stone dead. It's a freezing void that isn't prepared to lift a single finger to support human life, and getting exposed to it is pretty much an instant death sentence. Or is it? Just how long can a human survive in space, anyway? Let's find out!
A human can survive in space for 90 horrible, horrible seconds
According to Business Insider, you can indeed survive in the cold, unforgiving vacuum of space without a space suit ... for roughly a minute and a half. Said 90 seconds would not a space odyssey make, but they would do all sorts of terrifying things to your body, and the level of horror you'd experience depends heavily on your own actions and whether you have anyone to help you. If you did the instinctive thing and held your breath before being exposed to space, it's instant game over — the vacuum will immediately suck the air out of your body, so your lungs are going to rupture if they have any air left in them.
Even if you knew to empty your lungs, things will get uncomfortable. Whatever oxygen there is in your system will expand, causing you to "balloon up to twice your normal size" almost immediately, with only the elasticity of your skin keeping you from exploding. Oh, and the fascinating things that space does to the human body are not limited to turning your body into an improvised flesh balloon, as all exposed liquids in your body also start vaporizing (read: The surface bits of your tongue and eyes will suddenly start to boil). You'll pass out after 15 seconds or so, and if you have no one to haul you back in the safety of your cool space ship, the lack of oxygen will finish you off after 90 seconds.
What happens to a dead body in space?
After a human being dies in space, they briefly become a Starship Enterprise for their own gut bacteria, which survives longer than its host and starts to eat the body. However, this is unlikely to take too long, as the body will freeze entirely in 12 to 26 hours — or, if the death takes place in a relative vicinity to a star, it might instead "be burnt to a crisp." Regardless of which thing will happen, the end result can be preserved in space for millions and millions of years.