[Zeppo]

Interesting... Most of those impacts seem to be missing the central uplift of the “fried egg” (or else it is obscured by dust and debris) - perhaps due to differing substrate materials at the point of impact...

[stormer]

Interesting observation. Here's an example from Ganymede - the central mounts seem to be evident. I could only speculate as to any of a number of variables. Substrate, energy at impact, and gravity would seem to be the main culprits.

[stormer]

I also wonder if there is any vertical exaggeration in the original image that would make the central mounts appear more profound (not uncommon to demonstrate morphology).

[UCANSEE2]

The real key to why the fried egg effect, is whether the area was covered in water, as it is now.

[Gandalf_The_Gray]

Most of those impacts seem to be missing the central uplift...perhaps due to differing substrate materials at the point of impact...

The Moon has a very small iron core(in proportion to Earth). Mars also has a small core and it seems to be solid rather then molten. I expect that might explain the difference in appearance as an impact on Earth's crust would look more like a stone dropped into water (and frozen immediately) as opposed to a bullet fired into a rock surface.

Regards,
GtG