I know this is small on the scale of things, but it really breaks the immersion for me. 

There are 2 problems with planetary bombardments. The first is that the planet continues to rotate under the explosions/mushroom clouds. Meaning that the explosions/mushrooms clouds remain stationary, kinda floating while the planet continues to rotate.

The second problem is there appears to be some texture seams that are exposed during bombardment which cut off the explosion/mushroom cloud.