Post History

<blockquote>So couldn't earth be odd shaped other than a sphere?</blockquote>

No.  Something the size of the earth has significant gravity.  There isn't material strong enough over large distances to result in anything more than a slightly wrinkled surface for an earth-sized object.  Put another way, the vertexes of the cube would be very high mountains that wouldn't stay that way very long, let alone a mechanism to create such mountains in the first place.

If the earth were scaled to the size of a ping-pong ball, it would be much smoother than a ping-pong ball.

Note that even the significantly smaller moon is still <i>much</i> more rounded than a cube.  The comet you are referring to has an odd shape that hasn't collapsed to a ball because it is so small.  The adhesion of its material is much stronger relative to the comet's tiny gravity, than piles of rocks are relative to earth's 1 g gravity.