Impact structure

[1] This is the fate of almost all old impact craters on Earth, unlike the ancient pristine craters preserved on the Moon and other geologically inactive rocky bodies with old surfaces[2] in the Solar System.

Impact structure is synonymous with the less commonly used term astrobleme meaning "star wound".

Any meteorite fragments that may once have been present would be long since eroded away.

Possible impact structures may be initially recognized by their anomalous geological character or geophysical expression.

These may still be confirmed as impact structures by the presence of shocked minerals (particularly shocked quartz), shatter cones, geochemical evidence of extraterrestrial material or other methods.