We always see spacemen wearing their spacesuits to presumably protect themselves from the vacuum of Space. In film culture, it is believed that exposure to this vacuum immediately blows you up, thus killing you. In this article, we will discuss what would actually happen to you if you one day forgot your spacesuit on your trip to Space!

Going to Space with no Spacesuit

This may let some of you down, but the human body does not explode if exposed to the vacuum of Space, although… a lot does start to happen. Before we dive right into it we must first understand what the term vacuum of Space means.

What is a Vacuum?

A vacuum is a volume of space with absolutely no matter in it whatsoever. This means no physical objects, not even air. As you can imagine, Space is not a perfect vacuum - it has bits of dust flying around occasionally, but it is pretty darn close to perfection. When we say ‘vacuum of Space’, it just means the empty part of Space.

So, what happens?

We will now go through what would happen to you, in order.

1) You cannot breathe

This one might strike you as obvious, but it’s not just due to the lack of oxygen. Space is a giant vacuum as discussed above; because of this, the pressure is ridiculously low. Since Space is a lot bigger than the human, anything of higher pressure will try to disperse in Space to make its pressure lower like its surroundings. What does this mean? This means any air in your lungs will be forced out into the void of Space. If you try to hold your breath? Game over. Your lungs explode and you die almost instantaneously.

2) Your body expands by twice its size

What about the Nitrogen in your blood, that must go somewhere… right? Since it is in your blood, the problem is it is enclosed by your blood vessels, which are enclosed by your organs, which are enclosed by your skin – so it can’t go anywhere. This causes expansion of this Nitrogen due to the huge pressure differences. This expansion would be so drastic that you become up to twice your size – but you won’t blow up since your skin is extremely stretchy. This process would cause excruciating pain.

3) Water boils so quick it instantly vaporizes

Thermodynamics tells us that if you reduce the pressure, you reduce the boiling point. In Space, due to the incredibly low pressure, it drastically reduces the boiling point of water meaning it would almost instantly vaporise if exposed to this harsh vacuum. Luckily, most of the water is in your body meaning it is safe, but you have water on your eyes, lips and tongue. These would begin to boil very quick. You could try closing your eyes but the steam would force them back open.

At this point you are still alive, but in a lot of pain. What now?

4) The worst sunburn man has ever seen!

On Earth, we live in a nice little bubble with our atmosphere protecting us from the Sun’s harmful radiation; Ultraviolet light. In Space, there is no atmosphere to protect you from all this UV so you don’t just tan… you are left with the worst possible sun burn imaginable! In Space, you also have Gamma rays and X-Rays whizzing about which would most likely damage your DNA. So if you make it out of Space alive, chances are cancer will catch up on you.

This would all happen in about 3 minutes. After that you would pass out due to the lack of Oxygen and die soon after.

5) Your body freezes

Space is cold. In fact, it is -270 degrees Celsius. Considering the already reduced boiling point of water due to the low pressure (as mentioned above) freezes quickly. Within the next 12-24 hours you become a bright red, inflated, rock solid balloon drifting through space. Nice.

You’ll be fine though if you don’t forget your Spacesuit, or if you just didn’t go to Space at all - so don’t fret! You’re safe.

If you have any questions, leave them below and until next time, take care.

~ Mystifact

Relevant articles:
Are we alone in the Universe?
Why can't we fly a plane into Space?
Can we turn Mars into Earth 2.0?
The Wrath of a Neutron Star

Previous articles:
The Science of Tanning: What does the Sun do to your Skin?
Wonders of Quantum Physics: "What is Matter?" - Episode 2
How do Rainbows form?