Crater Help.

Is there someone on ATS who can help me by explaining how these craters are formed?


This is on the moon.



ida.wr.usgs.gov...
This one is on Mars.

I was always under the impression that a meteorite would be destroyed from the impact. I don't understand how there is a mass inside the craters like these.

Does anyone know how these were formed?

It's called a Complex Crater, they aren't all that uncommon.

www.geologyrocks.co.uk...



Differences in formation of a simple crater and a complex crater. The central peak of the complex crater is formed as a result of uplift of material stratigraphically beneath the crater, which rebounds in response to compression caused by the impact. From Melosh (1989

A quick look at the Forum Reference Library could have helped you out. Try this one: Crater Forms

Great thanks guys.
Sorry, I don't think I've ever looked at your Forum Reference Library. I'm going to go check it out right now.

It's facinating how fluid solid material gets under these extreme contitions. It reminds me of high speed films "slow-motion" of drops of liquid landing. They always produce that trademark rebound droplet in the center.

OMG.....the second photo, the one of the Mars crater, looks like a golf ball stuck in it!!?? Seriously that is the oddest crater I've seen in a while! Does it look like there is a 'grid' on that lump to anyone else?

Thats a dune field, in the bottom of that Mars crater.
Opportunity rover gave us a close-up look at a similar dune field
at the bottom of Endurance crater last year.
Here is a false color image of a portion of that dune field..



You can see some criss-crossing ( golf ball dimples?) in this image.