THEMIS mosaic in perspective
October 12, 2009
This figure shows a mosaic of THEMIS day and night infrared images of Melas Chasma. The daytime temperature images are shown in black and white, superimposed on the martian topography. A single THEMIS nighttime temperature image is superimposed in color. The daytime temperatures range from approximately -35 degrees C (black) to -5 degrees C (white). Overlapping landslides and individual layers in the walls of Melas Chasma can be seen in this image. The landslides flowed over 100 km across the floor of Melas Chasma, producing deposits with ridges and grooves of alternating warm and cold materials that can still be seen. The temperature differences in the daytime images are due primarily to lighting effects, where sunlit slopes are warm (bright) and shadowed slopes are cool (dark). The nighttime temperature differences are due to differences in the abundance of rocky materials that retain their heat at night and stay relatively warm (red). Fine grained dust and sand (blue) cools off more rapidly at night. These images were acquired using the THEMIS infrared Band 9 centered at 12.6 micrometers.
Topics: Melas Chasma, Coprates quadrangle, Chasma, Planetary geology, 24 Themis, Hebes Chasma, Thermal Emission Imaging System