Could two planets share an atmosphere?

Question

Imagine two planets about the size of the Earth, their centres about 20 000 km apart, orbiting a common centre of mass. So their surfaces would be about 7000 km apart. Could they have a common atmosphere or would it quickly leak away into space? Would this configuration be stable?

Answer 1

At 7,000 km, the tidal forces would be so great that the two planets would probably tear each other apart with gravity. But if they were really strong to resist that force, they would still be too far apart to really exchange atmospheric gasses with each other. Earth's atmosphere only extends up 100 km or so.

Answer 2

It is possible, but a very unstable system. If they share their atmosphere, friction will occur in the air, that will cause the 2 planets to get closer and closer to finally reach each other. Such a system wouldn't last a year

peace

Answer 3

interesting they would morph into 1 planet after soon time i guess

Answer 4

id think that they'd crash into each other and somehow throw of the natural balance of things.