Constraining geologic properties and processes through the use of impact craters.

Impact cratering is the one geologic process which is common to all solar system objects. Impact craters form by the resulting explosion between a solar system body and hypervelocity objects. Comparison with craters formed by chemical and nuclear explosions reveals that crater diameter is related to other morphometric characteristics of the crater, such as depth and rim height. These relationships allow scientists to use impact craters to probe the subsurface structure within the upper few kilometer of a planetary surface and to estimate the amounts and types of degradational processes which have affected the planet since crater formation. Crater size–frequency distribution analysis provides the primary mechanism for determining ages of planetary terrains and constraining the timing of resurfacing episodes. Thus, impact craters provide many important insights into the evolution of planetary surfaces. [ABSTRACT FROM AUTHOR]