The vacuum of space, however, is much more hostile. Without this lovely thick atmospheric blanket, you're exposed to all sorts of things. The most serious dangers of exposure to outer space are a lack of oxygen and ebullism. Ebullism is the formation of bubbles in body fluids due to a reduction in ambient pressure. read more
After around 15 seconds, your body would have used up all of the oxygen in your body and you’d lose consciousness. Some of you may be thinking “But I can hold my breath for minutes!” The situation in space is a little different than here on Earth due to the lack of outside pressure, and if you held your breath in space without a suit you’d be in a big trouble. read more
If your body was sealed in a space suit, it would decompose, but only for as long as the oxygen lasted. Whichever the condition, though, your body would last for a very, very long time without air to facilitate weathering and degradation. Your corpse could drift in the vast expanse of space for millions of years. read more