Martian lava channels. Coloured satellite image of channels carved by hot flowing lava on the slopes of Ascraeus Mons, a volcano near Mars' equator. Colours indicate nighttime temperatures, ranging from red (warmest) to blue (coolest). Areas covered in fine dust have cooled quickest and are blue. In the lava channels areas of exposed rock are warmest (red), while areas that have a mixture of rock and dust are cooler (yellow). Image obtained by the Thermal Emission Imaging System (THEMIS) aboard NASA?ａ?s Mars Odyssey orbiter.