How to distinguish an explosion crater from an impact crater?

Question

(How) Is it possible to tell the difference between a man made explosive crater and an impact crater?

Answer 1

If the explosion was caused by a non-atomic weapon, the temperature of the explosion was not high enough to melt the rock, therefore you would still see a lot of sedimentary rocks or igneous on the surface. In the event of a large impact from a comet or asteroid, the temps may have been high enough to melt the the rock and turn it into a metamorphic rock.

This is what I would look for. In the event of small impacts, your best bet is to scan the rock types with advanced equipment and it will determine if the rock is terrestrial or not.