Why doesn’t the atmosphere (air we breathe) just float off into space?
Some objects in space have atmospheres like Earth and Jupiter. Others like asteroids and the moon don’t have an atmosphere.
Why doesn’t earth atmosphere just drift away into space?
What am I missing about the concept of atmosphere?
In: Planetary Science
This does happen for some of the lighter gases. Even though the Universe is 75% hydrogen, we don’t have any substantial amount in our atmosphere. Why could that be? It turns out that you can do rough relation between the velocity of a particle and its temperature. At Earth temperatures, light elements like hydrogen move faster than Earth’s escape velocity (how fast you have to go to overcome gravity and leave the Earth) for no other reason than their temperature. So we lose them. However, this like nitrogen, O2, whatever, do not exceed the escape velocity with their thermal speed, so they stick around due to gravity.
Latest Answers