Context image

This VIS image shows part of Hephaestus Fossae. Hephaestus Fossae is a complex channel system in Utopia Planitia near Elysium Mons. It has been proposed that the channel formed by the release of melted subsurface ice during the impact event that created the crater just off the bottom right of the image – only the ejecta is seen in this image. The crater is fairly young, as there is only minimal modification of the crater floor. While it appears that the crater sits of top of the channel, the creation of the crater may have also created the channel. The impact event would have caused subsurface heating, melting any subsurface ice in the region which would have created surface flow to form the channel. Additionally, the nearby Elysium volcanic center created subsurface heating that may have played a part in creating both Hephaestus Fossae and Hebrus Valles to the north.

The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from using multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

Orbit Number: 86796 Latitude: 17.9392 Longitude: 125.437 Instrument: VIS Captured: 2021-07-09 02:13

Please see the THEMIS Data Citation Note for details on crediting THEMIS images.

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.