What would happen to a human body if it was exposed to outer space without a space suit?

Question

A friend and I are arguing about this. I think they would freeze to death because there are few molecules around them to hold warmth. He says that the human body would explode because the pressure inside the body has nothing pushing against it from the outside.

Who is right? Are we both wrong?

Answer 1

Asphyxiation and freeze




U.P.

Answer 2

If you don't try to hold your breath, exposure to space for half a minute or so is unlikely to produce permanent injury. Holding your breath is likely to damage your lungs, something scuba divers have to watch out for when ascending, and you'll have eardrum trouble if your Eustachian tubes are badly plugged up, but theory predicts -- and animal experiments confirm -- that otherwise, exposure to vacuum causes no immediate injury. You do not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness.

Various minor problems (sunburn, possibly "the bends", certainly some [mild, reversible, painless] swelling of skin and underlying tissue) start after ten seconds or so. At some point you lose consciousness from lack of oxygen. Injuries accumulate. After perhaps one or two minutes, you're dying. The limits are not really known.

You do not explode and your blood does not boil because of the containing effect of your skin and circulatory system. You do not instantly freeze because, although the space environment is typically very cold, heat does not transfer away from a body quickly. Loss of conciousness occurs only after the body has depleted the supply of oxygen in the blood. If your skin is exposed to direct sunlight without any protection from its intense ultraviolet radiation, you can get a very bad sunburn.
You would probably pass out in around 15 seconds because your lungs are now exchanging oxygen out of the blood. The reason that a human does not burst is that our skin has some strength. For instance compressed oxygen in a steel tank may be at several hundreds times the pressure of the air outside and the strength of the steel keeps the cylinder from breaking. Although our skin is not steel, it still is strong enough to keep our bodies from bursting in space.

Also, the vapor pressure of water at 37 C is 47 mm Hg. As long as you keep your blood-pressure above that (which you will unless you go deep into shock) your blood will not boil. My guess is that the body seems to regulate blood pressure as a gauge, rather than absolute pressure (e.g. your blood vessels don't collapse when you dive 10 feet into a pool).

The saliva on your tongue might boil, however.

Answer 3

Whether you freeze or burn depends on where you are at the time. Direct exposure to the sun will cause temperature to increase, because the sun will impart heat energy to your body faster than it can radiate out of your body. Without air around you, there's no medium to help conduct heat away. If you are in shadow, your body will radiate heat away, but again, there will be no medium around you to moderate the heat loss. In shadow,you would eventually freeze. The Apollo astronauts had temperature control layers in their suits, with fluid tubes built into the body, sleeves, and legs of the layer to circulate temperature-controlled liquid around their bodies to protect against temperature changes. They also had layers to protect against micrometeor damage and radiation. The worst part is that without atmospheric pressure around you, the dissolved gasses like oxygen and carbon dioxide in your blood will rapidly come out of solution. Like when you shake a soda can and open it... only it is going to happen where the small caplillary blood vessels run through the spongy tissues in your lungs. Your lungs are the easiest point of exit if your blood gets hot enough to burst vessels. However, your body doesn't "need" pressure to stay together, as long as the fluids in it are below the boiling point. Maybe, if your body gets hot enough from sunlight, the ocular fluid in your eyeballs will boil, but probably not before the hard ultraviolet and raw protons burn your skin to a dry solid. Of course, the real question is, how long can you go without air?

Answer 4

Lost pressure would cause the tissues and blood to boil and the body would explode.

Answer 5

You wouldn't live long enough to freeze. Ones blood would boil away and the body would explode.

Answer 6

You would lose consciousness after about 10 seconds, then all the gases inside your body would slowly seep out all the airways. So you would eventually freeze to death.

Answer 7

It is difficult to say if the body would freeze before it explodes or explodes before it freezes. Either way, you're dead.

Answer 8

well,ur friend is right in sense..
then blood flows out of the body.
the reason for this is that the pressure in the space is lower than the body.so automatically, the liquids flows from high pressure to low pressure.

Answer 9

The skin will start to have bubbles, like if you would boil water.
Then you will first die because you won't have oxigen and then freeze.