Part 4/9:
In the exosphere, about 1,000 kilometers above Earth, pressure is nearly nonexistent. Here, a piece of iron remains unchanged, but hydrogen gas expands rapidly when released, becoming a cloud. Water behaves uniquely, boiling, evaporating, and freezing simultaneously when exposed to the vacuum of space. This reveals that the liquid state of water is heavily dependent on ambient pressure. Humans would survive mere seconds in such conditions, as blood would boil due to low pressure.
High Altitudes
As we ascend to the upper mesosphere, the pressure remains low. At 100 kilometers altitude, water can’t exist in liquid form; it either freezes or sublimates directly to gas. At such altitudes, life as we know it would have no chance of survival.