A Heart in Ascraeus Mons
NASA/JPL/University of Arizona
A Heart in Ascraeus Mons
ESP_035807_1885  Science Theme: Volcanic Processes


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What is this strange-looking feature? HiRISE scientists first noticed it in images from the Context Camera and acquired this picture to investigate more closely.

The feature indeed does look like a heart. It is located south of Ascraeus Mons, which is a large volcano within the Tharsis volcanic plateau, so it is extremely likely that this feature was formed by a volcanic process. The feature rises above the surrounding terrain and we can see concentric ridges on its top. Perhaps this feature is an ancient vent structure (an opening in the ground from which volcanic lava emerges) that has been more resistant to erosion than the surrounding area, so that it resembles “inverted” terrains.

Topographic inversion or inverted terrain often occurs when low areas of a landscape become filled with lava or sediments that harden into materials which are more resistant to erosion than the materials that surround them. Differential erosion then removes the less resistant surrounding material, leaving behind the younger resistant material which may then appear as a ridge where previously there was a valley, or in our case, a butte, where there was once a pit or depression.

Additional imaging of the feature to create a stereo and a digital terrain model may help in further assessing the structure by making accurate measurement of its height and the steepness of its slopes.

Written by: Ramy El-Maarry (audio: Tre Gibbs)   (9 April 2014)

This is a stereo pair with ESP_036862_1885.

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Acquisition date
17 March 2014

Local Mars time:

Latitude (centered)

Longitude (East)

Range to target site
270.3 km (168.9 miles)

Original image scale range
54.1 cm/pixel (with 2 x 2 binning) so objects ~162 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection

Emission angle:

Phase angle:

Solar incidence angle
50°, with the Sun about 40° above the horizon

Solar longitude
103.6°, Northern Summer

North azimuth:

Sub-solar azimuth:
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Black & white is 5 km across; enhanced color about 1 km
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All of the images produced by HiRISE and accessible on this site are within the public domain: there are no restrictions on their usage by anyone in the public, including news or science organizations. We do ask for a credit line where possible:
NASA/JPL/University of Arizona

For information about NASA and agency programs on the Web, visit: http://www.nasa.gov. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. The image data were processed using the U.S. Geological Survey’s ISIS3 software.