[panaxanax]

"I'm thinking that moon doesn't rotate."

It does appear that way, doesn't it? I would think that the craters near the edge would be elongated rather than perfectly round. Interesting picture, however.

[burzum]

Craters are never elongated unless they impact at less than the speed of sound for the rock that they hit. It would be extremely rare for such a low speed impact. When the impact is faster than the speed of sound for the rock that is hit, the energy transmitted to the rock builds up faster than it can dissipate leading to an explosion. This explosion occurs from the release of energy at one point and is completely symmetric. This is why it doesn't matter at which angle a meteorite strikes a surface, the resulting crater will always be mostly circular.

Next time you look at the moon consider how many impacts were at shallow angles but yet all the craters are round. Also consider how impossibly rare it would be for all the impacts to hit the moon normal to the surface.

[orionblamblam]

> I would think that the craters near the edge would be elongated rather than perfectly round.

Nope. It's not intuitively obvious, but craters are almost *never* anythign but basically circular, no matter what the angle of impact was. You can demo this at home... get a big pan, fill it with flour, and drop small rocks into it. You'll get circular craters. Now *toss* them in at weird angles. You'll still get round craters. On the moon, there are are a few strings of craters formed from *extremely* shallow impacts... basically, the rock skipped over the surface. Each individual crater is round.