HiRISE | ESP_025620_2275_ESP_025277

NASA/JPL-Caltech/UArizona

Utopia Planitia Scallops, Polygons, and Boulders
ESP_025620_2275_ESP_025277_2275

This terrain is covered by pits and scallops (pits open on one side), perhaps due to collapse after sublimation of subsurface ice.

This full-resolution anaglyph sample shows that the surface is cut into many polygons about 10 meters wide, that form as ice expands and contracts with temperature changes. There are also many meter-scale boulders on the surface, which must be rocks rather than blocks of ice, or they would not be stable on the surface.

More than 10 meters thickness of ice must have sublimated from some areas. How did the ice get deposited? One idea is that its from snowfall (in a different climate), but then it is difficult to explain the presence of the boulders. The other possibility is transport through the shallow subsurface in very thin films of water over many years.

View the standard observation with image products here.

Written by Alfred McEwen

IMAGE PRODUCTS
Map projected reduced-resolution (PNG)

Full resolution JPEG2000

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

STEREO PAIR
Left observation
ESP_025620_2275

Right observation
ESP_025277_2275

Contrast stretch
NONLINEAR

Convergence angle
29.9 degrees

Image lines
60539

Line samples
22749

RESOURCES
About anaglyph products (PDF)

POSTSCRIPT
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. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona.