Odyssey's THEMIS Views Olympus Mons

NASA's 2001 Mars Odyssey orbiter captured this single image of Olympus Mons, the tallest volcano in the solar system, on March 11, 2024. Besides providing an unprecedented view of the volcano, the image helps scientists study different layers of material in the Martian atmosphere, including clouds and dust. The panorama was created by rotating Odyssey so that its camera, the Thermal Emission Imaging System (THEMIS), faced the horizon of Mars as the orbiter soared past. This shot was among several taken in the latest effort by Odyssey using this technique; capturing this sort of horizon imagery at different times of year allows scientists to study how the atmosphere changes over seasons. The bluish-white band at the bottom of the atmosphere hints at how much dust was present when the image was captured during Mars' dust season. A purplish layer follows, likely due to a mixture of Mars' red dust with some bluish water-ice clouds. Finally, a blue-green layer can be seen where water-ice clouds reach up about 31 miles (50 kilometers) into the sky. https://photojournal.jpl.nasa.gov/catalog/PIA26305