all 4 comments

[–]chadwickofwv 4 insightful - 1 fun4 insightful - 0 fun5 insightful - 1 fun -  (3 children)

It is due to the electromagnetic field of the earth. The outer part of the atmosphere is made up of highly charged plasma. The magnetic field pushes down on that plasma keeping most of it on the planet. The solar wind replenishes what is lost, keeping it from slowly just dissipating into space.

[–][deleted] 3 insightful - 1 fun3 insightful - 0 fun4 insightful - 1 fun -  (2 children)

Mars is a fantastic example of what happens when the electro magnetic field becomes absent. After the core became inactive, the magnetic field was no longer present and the solar winds stripped the atmosphere off the planet.

[–]FuckYourMom 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 1 fun -  (1 child)

Well that’s nightmare fuel.

[–][deleted] 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 1 fun -  (0 children)

Best not to think about it too much.