This THEMIS image shows part of the southern margin of the summit caldera. This image contains a variety of features representing the major events related to the formation of the volcano. At the top of the image a small linear vent has produced lava flows increasing the elevation of the surface around it. The flat floor of the caldera surrounds the vent and the cliff faces at the center of the image were created during the collapse event that formed the caldera. Depressions at the bottom illustrate collapse into empty voids like lava tubes.
<p><a href="https://en.wikipedia.org/wiki/Arsia_Mons" class="extiw" title="w:Arsia Mons">Arsia Mons</a> is the southernmost of the <a href="https://en.wikipedia.org/wiki/Tharsis" class="extiw" title="w:Tharsis">Tharsis</a> volcanoes. It is 270 miles (450 km) in diameter, almost 12 miles (20 km) high, and the summit caldera is 72 miles (120 km) wide. For comparison, the largest volcano on Earth is <a href="https://en.wikipedia.org/wiki/Mauna_Loa" class="extiw" title="w:Mauna Loa">Mauna Loa</a>. From its base on the sea floor, Mauna Loa measures only 6.3 miles high and 75 miles in diameter. A large volcanic crater known as a caldera is located at the summit of all of the Tharsis volcanoes. These calderas are produced by massive volcanic explosions and collapse. The Arsia Mons summit caldera is larger than many volcanoes on Earth.
</p><p>The Odyssey spacecraft has spent over 15 years in orbit around Mars, circling the planet more than 69000 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!
</p><p>Orbit Number: 63900 Latitude: -10.0873 Longitude: 239.197 Instrument: VIS Captured: 2016-05-10 07:58
</p><p>Please see the <a rel="nofollow" class="external text" href="http://themis.asu.edu/terms">THEMIS Data Citation Note</a> for details on crediting THEMIS images.
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NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Science Mission Directorate, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
NASA/JPL-Caltech/ASU
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