How does a planet maintain its atmosphere?

Question

Thanks for all the help!!

Answer 1

Pleasant conversations, juke box, cool beer, pool table, amiable host - you know the sort of thing.

Answer 2

Besides gravity and a magnetic field, there are also active processes involved in some cases. Earth would not be able to maintain the level of oxygen it does without plants to replenish it. Biological processes also cycle nitrogen and carbon dioxide. Physical processes such as volcanic eruptions are another contributor to atmospheres. Then there are equilibrium cycles with reservoirs of material vaporizing and condensing. This happens with water on Earth, and methane on Titan.

Answer 3

If the mass of the planet is great enough for it s gravity to keep the molecules close. A good example are the moones of saturn. The second largest moon in our solar system, Titan, orbiting around saturn, actually has a dense atmospshere because it s mass is so great and larger than the planet mercury!

Answer 4

Gravity and magnetic field. Gravity keeps the molecules and atoms from escaping thermally and the planetary magnetic field cuts down on the solar wind which will strip the atmosphere by collisions.

Answer 5

well, its mostly due to the fact that we have gravity, and also due to the nature of gases, generally sticking together. But what i think is most important is the fact that it rotates, and it is this that keeps it with us.

cheers