THEMIS Image of the Day, September 1, 2017. This image shows part of the southern flank of Ascraeus Mons. The feature at the bottom of the image is a collapse feature. These features can be caused by several processes. The ceiling of lava tubes can collapse into the open space left after the last flow. Tectonic activity can occur, and blocks of material can drop down between faults. The tectonic features are called graben. All three of the Tharsis volcanoes (Ascraeus, Pavonis and Arsia mons) are aligned along a northeast/southwest trend. The largest region of collapse features on each of the three volcanoes are located along this trend.
NASA’s Mars Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69,000 times. It holds the record for longest working spacecraft at Mars. THEMIS, the IR/VIS camera system, has collected data for the entire mission and provides images covering all seasons and lighting conditions.
Over the years many features of interest have received repeated imaging, building up a suite of images covering the entire feature. From the deepest chasma to the tallest volcano, individual dunes inside craters and dune fields that encircle the north pole, channels carved by water and lava, and a variety of other feature, THEMIS has imaged them all.
For the next several months the Image of the Day will focus on the Tharsis volcanoes, the various chasmata of Valles Marineris, and the major dunes fields. We hope you enjoy these images!
More THEMIS Images of the Day by geological topic.