Moon Question (Vacuum, air, escape vel.)

[nukeman]

Ok, this might seem like a silly question, but I just want to get it straight. Just tell me if anything I am saying is wrong, and answer the best you can.

Ok, the moon has no air, because it has no atmosphere correct? And the reason for no atmosphere is because the moon is biologically non-active, and the moon does not have enough mass to keep things from escaping the moon, including gases, which the moon does not give off because its biologically dead ?

The moon is simply apart of the vacuum of space because of the atmosphere correct?

So, the reason someone on the moon would not drift off into space if they jumped in the air is because the moon still of course has gravity, as everything with mass has gravity.


Now its your turn :)

Thanks guys!

 

[fss]

Ok, the moon has no air, because it has no atmosphere correct?

Having an atmosphere doesn't necessarily mean having air...

The moon is simply apart of the vacuum of space because of the atmosphere correct?

This doesn't make much sense to me either. "Apart of the vacuum of space?" Vacuum is, by crude definition, the absence of matter.

So, the reason someone on the moon would not drift off into space if they jumped in the air is because the moon still of course has gravity, as everything with mass has gravity.

Right.

 

[DaveC426913]

fss covered most of it. A few tweaks:

And the reason for no atmosphere is because the moon is biologically non-active, and the moon does not have enough mass to keep things from escaping the moon, including gases, which the moon does not give off because its biologically dead ?

Planets certainly off-gas without being biologically active. Europa is spewing sulphur clouds from its interior.

But Europa is tectonically active; it has a liquid core. The Moon's core has long since cooled and is now dead. That's why it does not off-gas.

So, the reason someone on the moon would not drift off into space if they jumped in the air is because the moon still of course has gravity, as everything with mass has gravity.

Well, of course, they couldn't "jump in the air" on the Moon, could they?

But yes, gravity is what holds things down, not atmo.

 

[qraal]

fss covered most of it. A few tweaks:

Planets certainly off-gas without being biologically active. Europa is spewing sulphur clouds from its interior.

But Europa is tectonically active; it has a liquid core. The Moon's core has long since cooled and is now dead. That's why it does not off-gas.

Io is the volcanic one. It has a thin atmosphere of mostly sulfur dioxide from all the sulfur and the like. During Io's night the atmosphere freezes, then defrosts just after dawn. Europa has a very, very thin atmosphere of oxygen, from ice that has been exposed to Jupiter's radiation belt and broken into oxygen and hydrogen.

Well, of course, they couldn't "jump in the air" on the Moon, could they?

But yes, gravity is what holds things down, not atmo.

The Moon BTW doesn't have an atmosphere because it was blown away, long ago, by the Solar Wind.

 

[pmacias]

Hello! I can confirm that your understanding of the moon's atmosphere and escape velocity is correct.

The moon does not have a significant atmosphere because it does not have enough mass to hold onto gases and create an atmosphere like Earth's. This is due to its smaller size and lack of geological activity that could replenish the gases. The moon's atmosphere is also constantly being bombarded by solar winds, which can strip away any gases that may have accumulated.

The moon's escape velocity is the speed at which an object needs to travel in order to break free from the moon's gravitational pull. As you mentioned, the moon does have a gravitational force, but it is much weaker than Earth's due to its smaller mass. This means that the escape velocity on the moon is much lower compared to Earth, making it easier for objects to leave its surface.

So to answer your question, someone on the moon would not drift off into space if they jumped because the moon's gravitational force is still strong enough to hold them on its surface. However, if they were to jump with enough force to reach the moon's escape velocity, they would indeed float away into space.

I hope this helps clarify any confusion and feel free to ask any other questions you may have! Science is all about learning and understanding, so never hesitate to ask.