Robert Sharp is a crater on the planet Mars in the northeastern part of Mare Tyrrhenum quadrangle at 4.17°S 133.42°E / -4.17; 133.42. The crater is 152.08 km Robert Sharp Crater was named for geologist and planetary scientist Robert P. Sharp by the USGS and IAU on May 16, 2012. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On Mars large craters are named after deceased scientists, writers and others who have contributed to the lore of Mars. Small creaters (less than 60km) are named after small towns and villages.