What types of terrain are found on Mars? Part of the answer comes from thermal imaging by the robot spacecraft 2001 Mars Odyssey [ http://mars.jpl.nasa.gov/odyssey/overview/index.html ] currently orbiting Mars [ http://www.nineplanets.org/mars.html ]. The above picture [ http://photojournal.jpl.nasa.gov/catalog/PIA03741 ] is a superposition of two infrared images [ http://themis.asu.edu/inst.html ], a black and white image taken during Martian daylight and a false-color image taken at night. For the daytime image [ http://antwrp.gsfc.nasa.gov/apod/ap960207.html ], dark colors mean cool temperatures, dropping from about -5 degrees Celsius [ http://www.unidata.ucar.edu/staff/blynds/tmp.html ] to low as -35 degrees Celsius [ http://www.astro.uu.se/history/Celsius_eng.html ]. Shadowed regions appear particularly dark, while grooved structure [ http://antwrp.gsfc.nasa.gov/apod/ap001218.html ] on the floor of Melas Chasma [ http://ic.arc.nasa.gov/ic/projects/bayes-group/Atlas/Mars/features/m/melas_chasma.html ] indicates successively overlapping landslides [ http://www.csc.noaa.gov/products/tsunamis/htm/cascadia/ld_intro.htm ]. In the nighttime swath, blue areas have cooled relatively quickly, indicating a composition of fine-grained dust and sand [ http://antwrp.gsfc.nasa.gov/apod/ap010226.html ].