Crater statistical analyses have been used successfully in three major ways, namely : (1) to understand planetary chronologies and to date geologic units and events, (2) to identify surface and subsurface processes, and (3) to provide a framework for interpretation of data from other fields.

Dating of planetary surfaces was one of the first applications of crater statistics. Through detailed study of crater size-frequency, density, and morphology [shape} distributions, reliable relative chronologies are being established for the Moon, Mars, and Mercury. [Crater counts were the first evidence to suggest that Venus has undergone catastrophic resurfacing.] For the Moon, where Apollo and Luna returned samples are available, Moon-wide absolute chronologies have been developed and are being extended across the surface. Many sub-disciplines of planetology require at least a framework of relative ages in order to interpret planetary evolution in terms of chemistry, structure, and processes; crater analyses are the chief means of obtaining this time framework. When combined with asteroid and comet surveys, crater statistics provide the only presently available means of establishing absolute (admittedly coarse) chronologies for Mercury, Venus, and Mars.

Because impact craters form at random locations on planetary surfaces, but geologic events often locally alter this uniformity, crater analyses have been useful for mapping geologic units of common origin and age. Furthermore, different geologic processes (e.g., aeolian [wind] erosion, volcanism, and tectonic disruption) affect crater size-frequency distributions and morphologies in characteristics manners. Through crater analyses a wide range of internal and surface geologic processes have been identified or contrasted on the Moon, Mercury, and Mars.

Crater analyses already have produced valuable and otherwise unattainable information, and the prospects for still further successes are excellent. Current competition and debate are producing rapid advancements and refinements of our understanding of cratering as a geologic process; recognition of the characteristics of primary and secondary cratering; understanding of the origin, evolution, and dynamics of small bodies in the solar system; and understanding of planetary crustal properties, environments, and evolution. As the techniques of crater analysis continue to expand the library of basic information about the terrestrial planets, their use and respect by other disciplines will continue to grow.