Orbital Dynamics - Shared Atmospheres?

[Sherlock21st]

This may sound like a really stupid question, but....

I want to know, theoretically, if two planets could orbit each other.

But that's not all

They are orbiting so ludicrously close that while one body is not inside the other's atmosphere, their atmospheres connect.

I want to know if such a thing is possible without the two ending up merging.

I want you to not consider any forces whatsoever that are not mentioned here.

For lack of a better picture:

Black represents the planets themselves

Gray represents their atmospheres

Sorry it looks like testicles.

Edited September 25, 2012 by Sherlock21st

[boac89]

I would guess (MUST HIGHLIGHT THIS IS A GUESS) that it's not possible. The gravitational forces wouldn't allow it. When the planets were first forming one planet would take precedence and the matter would flow to it. This would leave one large planet, and one smaller moon. Even if the moon was large enough to have a deep atmosphere, and it was sufficiently close for the larger body's atmosphere to join with it, the tidal forces would be so large as to cause damage to the moon and end up pulling it apart.

Just a guess.

[Person012345]

My guess is that the speeds and tidal forces involved in such a close orbit would be absurd and wouldn't allow it. As above, this is a guess.

[maltesh]

When it happens with stars, the situation is called a Contact binary. There are a number of asteroids believed to be contact binaries as well (though being asteroids, they aren't massive enough to have atmospheres, and are in presumed physical contact).

Robert L. Forward's Rocheworld series features a double-planet system. Haven't read it myself, though.