Chapter 12 - Modification of the Martian Surface by Impact Cratering

Abstract

Impact cratering is a pervasive geologic process that continually modifies the martian surface. Meters to tens-of-meters scale craters have been observed to form during the lifetimes of the Mars Global Surveyor and Mars Reconnaissance Orbiter missions providing direct observations of the present-day martian impact rate on a decadal timescale. Landscape modification by larger, higher energy impact events that occur on million year timescales are observed to be far reaching. For example, Corinto crater (D=13.8km) formed within the last ∼3Ma and modified Elysium Planitia over a radial distance exceeding 2000km by forming secondary craters. The secondary craters disrupted the surface material and, where concentrated, modified the surface thermal properties to form rays observable in IR observations. Corinto secondaries are found to influence crater size–frequency distributions at a distance of nearly 50 crater radii with concentrations suggesting Corinto generated billions of secondary craters.