Harden Elkington
Imagine you’re an astronaut exploring space and, uh oh, you accidentally fall out of your spaceship’s airlock.
What would happen to your body if it were exposed to a space vacuum without a spacesuit? The first thing to remember is that many Hollywood versions of this scenario are overly dramatic.
They depict people who are not wearing helmets or spacesuits exploding at the moment of exposure or their blood boiling.
But if you know anything about physics you should be able to appreciate that it’s impossible for human tissues to experience any kind of pressure change instantly.
Blood will not “boil” in your body until the overall pressure falls below 15 mmHg (about 0.5% at sea level), and at that point, it will not do so in an explosive fashion.
In fact, the only thing that will really happen to a person in space without a helmet is a very unfortunate mangling of their body tissues due to the force of being hit by your rapidly expanding body fluids.
The lack of air pressure also means that gas dissolved in your blood and other body fluids will come out of the solution and form bubbles.
These bubbles can block blood vessels, leading to serious medical problems such as heart attacks and strokes.
Finally, the lack of air pressure can also cause moisture on your skin to vaporize, which can lead to severe burns.
So while you may not explode or boil instantly when you’re exposed to a space vacuum, the following moments will likely still be very unpleasant.
Without a spacesuit, an astronaut in space wouldn’t survive long.
However, their death would occur within minutes rather than seconds, and it would be a horrible death with boiling bodily fluids and a nearly frozen nose and mouth.
How long can you survive in the vacuum of space without a spacesuit?
When it comes to answering this question, size matters.
Astronauts who are just wearing street clothes and boots without a spacesuit would likely survive only one minute or so if their face was exposed to the vacuum of space.
Having an oxygen mask would extend that time tenfold.
It’s also important to note that there might not be any air inside the spacecraft for the helmet to protect you from even if you were wearing a spacesuit.
If there’s no oxygen in the room, a respirator won’t help you-you must have oxygen flowing through your suit or else you will die very quickly too.
A person can survive about 20 seconds of exposure to space without a spacesuit by breathing pure oxygen through a respirator.
But if they need to be able to hold their breath, astronauts can survive for about 10 minutes without an oxygen tank.
If you were in the vacuum of space and had a spacesuit and helmet on, you’d have more than enough time to get back into your ship and save your life.
If someone has pressurized the interior of their spacecraft, you could survive for hours.
However, if your spacesuit were damaged somehow or there was no air inside your ship, then that time would be much shorter-perhaps only minutes.
Being in the vacuum of space is not like being underwater where it’s possible to breathe and live for many minutes without an oxygen tank.
The vacuum of space is a hostile environment that can quickly kill you.
So the next time you’re watching an astronaut floating around in space on TV, remember that they’re only safe because they’re wearing a spacesuit and helmet!
Would an astronaut explode in space?
In space, there is no air pressure to cause the human body’s tissues to rupture.
You’d expand a bit if any gas dissolved in your blood or cells was given enough time to come out of the solution and form bubbles, but you wouldn’t explode rapidly.
The same thing would happen to a person on Earth if they were suddenly exposed to a vacuum, they would just explode more slowly.
The reason people often think that astronauts will explode in space is because of the way Hollywood portrays it.
In movies and TV shows, the moment an astronaut’s helmet is removed they start violently exploding.
However, this doesn’t happen in real life because there is no air pressure to force the fluids in their body to rapidly expand.
Even if someone was exposed to space without a helmet on, they wouldn’t explode-they would just experience some really bad symptoms that could lead to death.
Without a spacesuit, an astronaut in space wouldn’t survive long.
However, their death would occur within minutes rather than seconds, and it would be a horrible death with boiling bodily fluids and a nearly frozen nose and mouth.
- See also: What would the world be like If the earth had two moons
- See also: What happens if a particle goes faster than light
Can you actually boil alive?
Blood won’t boil and your insides aren’t going to be turned into soup anytime soon (unless you also have a lot of steam in your body from being in a sauna or something).
But if you were left in the vacuum of space for about 5-10 minutes, then it’s possible that some parts of your skin could start to boil.
This boils down to the fact that water is more likely to stay as a liquid or vaporize into a gas depending on whether it’s exposed to air pressure.
The reason why parts of your skin would start to boil if they were left in space for long enough has less to do with your body and more to do with physics.
If you went to space without a suit, your skin would start to freeze because there is no air pressure to keep heat in.
Conclusion
If you were in the vacuum of space without a spacesuit, you would die within 1-10 minutes depending on your size.
You’d likely explosively decompress or your skin would start to boil if you tried holding your breath (and it would be very unpleasant either way).
If you had a spacesuit, helmet and oxygen supply though, you’d be perfectly safe.
So the next time you’re watching Star Wars and wondering about the plausibility of space explosions, remember that things are a bit more complicated in reality!
