I don't think something in space can end up looking like that (the "chomped" moon), even if it was unnaturally "busted up". I'd suggest making the damage more "rounded". As for the planet, you should show pollution as thick clouds, not graying the whole thing. You could make it a dull brown to show that there is no more vegetation (in place of the green that there used to be). You can show cities as clumps of light on the planet. Don't know how this would work on the moon piece though, considering it is so small.