7/14/2002: Asteroid moon

[Tobiasly]

Originally posted by Undertoad
And yet, the craters on it say that it's been hit by debris and it wasn't knocked out of orbit of its big brother, or so we have to assume.

Or maybe it was knocked <I>into</I> the orbit of the other. Or maybe they used to be part of a bigger asteroid, and a collision busted it into pieces, and these two pieces were at just the right distance for the smaller to begin orbiting.