Martian Cratered Highlands

This THEMIS nighttime temperature image shows the ancient, heavily cratered surface of the highlands between Isidis and Elysium Planitia. The image is centered near 9 N, 109 E, and covers an area approximately 32 km wide by 120 km long. The bright 'splashes' extending outward from the three large craters are the remnants of the rocky material thrown out when the impact occurred. The nighttime temperature differences are due primarily to differences in the abundance of rocky materials that retain their heat at night and stay relatively warm. Fine grained dust and sand cools off more rapidly at night. The circular rims of the craters in this region are warm at night, showing that rocks are still present on the steep walls inside the craters. The 'splosh' ejecta patterns are also warmer than their surroundings, and are covered by material that was blasted out when the craters formed. The temperatures in this scene vary from approximately -105 C (darkest) to -75 C (warmest). This image was acquired using the THEMIS infrared Band 9 centered at 12.6 microns.