Dynamic Mars
NASA/JPL/University of Arizona
Dynamic Mars
ESP_042572_2640  Science Theme: Climate Change

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This scarp at the edge of the North Polar layered deposits of Mars is the site of the most frequent frost avalanches seen by HiRISE. At this season, northern spring, frost avalanches are common and HiRISE monitors the scarp to learn more about the timing and frequency of the avalanches, and their relationship to the evolution of frost on the flat ground above and below the scarp.

This picture managed to capture a small avalanche in progress, right in the color strip. See if you can spot it in the browse image, and then click on the cutout to see it at full resolution. The small white cloud in front of the brick red cliff is likely carbon dioxide frost dislodged from the layers above, caught in the act of cascading down the cliff. It is larger than it looks, more than 20 meters across, and (based on previous examples) it will likely kick up clouds of dust when it hits the ground.

The avalanches tend to take place at a season when the North Polar region is warming, suggesting that the avalanches may be triggered by thermal expansion. The avalanches remind us, along with active sand dunes, dust devils, slope streaks and recurring slope lineae, that Mars is an active and dynamic planet.

Written by: Paul Geissler   (30 September 2015)

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Acquisition date
26 August 2015

Local Mars time:
13:30

Latitude (centered)
83.887°

Longitude (East)
235.068°

Range to target site
320.2 km (200.1 miles)

Original image scale range
64.1 cm/pixel (with 2 x 2 binning) so objects ~192 cm across are resolved

Map projected scale
50 cm/pixel

Map projection
Polarstereographic

Emission angle:
7.7°

Phase angle:
66.0°

Solar incidence angle
71°, with the Sun about 19° above the horizon

Solar longitude
32.9°, Northern Spring

North azimuth:
109°

Sub-solar azimuth:
311.8°
JPEG
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IRB color
map projected  non-map

Merged IRB
map projected

Merged RGB
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RGB color
non-map projected

JP2
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map-projected   (299MB)

IRB color
map-projected   (169MB)

JP2 EXTRAS
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map-projected  (138MB)
non-map           (110MB)

IRB color
map projected  (49MB)
non-map           (133MB)

Merged IRB
map projected  (283MB)

Merged RGB
map-projected  (249MB)

RGB color
non map           (110MB)
ADDITIONAL INFORMATION
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products
HiView

NB
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



USAGE POLICY
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



Postscript
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.