The most fascinating scene in the movie Mission to Mars (to young and childish me) was when Woody removes his helmet and dies to save Terri. Exposed to the vacuum of space, however I was uncertain how the real scenario of such episode would look like. Many movies like “total recall and outland” portray the same concept … Never could forget Arnold’s bulging eyes.
My attempted inception is to make you think about what happens, if we are exposed to vacuum of space! Well as the matter of fact most common perceptions are that blood and other body fluids will boil or body will explode!!
Well according to the astrophysicist team at NASA, “You do not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness.”… At least not instantly but, bottom-line is of course you will die, if you are not superman (which you, most probable are not! But, if you are… mail me! )
Let us take the case-by-case analysis on exposure to space vacuum, as shown in movies…
“Outland” instant explosion due to depressurization; on earth we are under the normal pressure conditions of one atmospheric pressure.However, if we decrease the pressure volume increases, according to basic law. So a common myth is you will explode! In the real-life scenario you will not explode because of the containing effect of your skin. However, the air would rapidly rush out of your lungs, leaving your lungs damaged. In a few minutes you will pass out, due to lack of oxygen. Over all your body is going to stay pretty-much intact as far as exploding myth is concern!
“Total Recall” Boiling of blood is generally associated with the same principle that, the boiling point of any liquid is decreased as pressure decreases. However, in this case the blood pressure is quite stable, because of closed circulatory system. But the saliva would start boiling within 10 to 15 seconds. A test subject was accidentally exposed to vacuum in 1965 at Johnson Space Center the subject passed out due to lack of oxygen within 14 seconds, he probably did not reach a hard vacuum though. Last thing he claims to remember is his tongue beginning to boil!
Freezing to death as in “Mission to Mars”, this one is not justified too. At least not as instant as it was in the movie. Pressure and temperature has a direct relation, but as far as the rate of heat transfer is concern, especially in lack of medium to transfer it, you are absolutely unlikely to freeze in nick of time. Vacuum of space itself has no temperature. Sun is hot and radiates that heat in the form of light. On earth we receive the light and feel the heat but in space sun’s radiation will not keep you warm. Due to the heat energy gradient, you will radiate away your heat in vacuum. But you would most likely to be dead before you freeze!
On sudden exposure to vacuum, a series of injuries leads to death. In a chronological order first of all, there will be expansion of gases in lungs and gastrointestinal tract. Over to this point if you try to hold your breath you will rupture your lungs, ending up with bubbles of air in your circulatory system. In vacuum the water molecules in your body will start to vaporize, after losing moisture from body, you will vaporize water molecule from every single cell. This would lead the body to swell to twice the usual size, breaking capillaries but not skin (No explosion, I promise…). Nitrogen dissolved in blood will not be dissolved anymore, as the pressure decreases the ability to dissolve gases reduces, it would form gaseous bubbles. Overall within 10-15 seconds you will start to feel uncomfortable. But yet it depends on the level and rate of exposure, how long you will stay conscious. However due to lack of oxygen you may not be able to concentrate on taking any safety measure. As your brain is not able to function properly you will experience loss of vision and impaired judgement. Cooling effects will start this point onwards as your nose and mouth will start to freeze. Unconsciousness will still have a few seconds to wait probably followed by blue skin. Once you go unconscious you can still survive this much a few more minutes… as the brain is not damaged and heart is still pumping blood. Even at this point if you are re-pressurized you will survive will non to minor injuries. But if you are not taken back to stable conditions, this limit is the critical threshold. Your blood pressure will fall to the extent that blood will start to boil and heart will stop. This critical verge of survival is not in seconds but minutes, you can survive space for about two minutes with totally reversible damage.
Hey! Do I need not to mention the extent of Sun Burn… I guess not.