Ancient Volcano Defrosting
NASA/JPL/University of Arizona
Ancient Volcano Defrosting
ESP_011605_1170  Science Theme: Volcanic Processes
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Malea Patera is one of a group of ancient volcanoes that ring the Hellas impact basin.

This HiRISE image was intended to investigate the nature of the volcanic materials at this location. However, the image was taken in early spring for this location in the southern hemisphere and so the ground is covered with bright frost except for some dark splotches found in discrete patches. This is where the sunlight has penetrated the frost and initiated defrosting around discrete spots.

Clearly something is different about the patches where this defrosting has started before any other locations. One possibility is that these are (frost covered) dark sand dunes that heat up more easily than the surrounding terrain. However, we will need to take a new image in the summer time to really know what is happening here.

Written by: Laszlo P. Keszthelyi   (4 March 2009)

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Acquisition date
16 January 2009

Local Mars time:

Latitude (centered)

Longitude (East)

Range to target site
249.1 km (155.7 miles)

Original image scale range
24.9 cm/pixel (with 1 x 1 binning) so objects ~75 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle:

Phase angle:

Solar incidence angle
73°, with the Sun about 17° above the horizon

Solar longitude
192.6°, Northern Autumn

North azimuth:

Sub-solar azimuth:
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IRB color
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Merged IRB
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Merged RGB
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RGB color
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map-projected   (665MB)

IRB color
map-projected   (295MB)

Black and white
map-projected  (249MB)
non-map           (439MB)

IRB color
map projected  (84MB)
non-map           (300MB)

Merged IRB
map projected  (173MB)

Merged RGB
map-projected  (162MB)

RGB color
non map           (270MB)
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products

IRB: infrared-red-blue
RGB: red-green-blue
About color products (PDF)

Black & white is 5 km across; enhanced color about 1 km
For scale, use JPEG/JP2 black & white map-projected images

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: 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.