Dry Ice Etches the Terrain on Mars
Dry Ice Etches the Terrain on Mars
PSP_003364_0945  Science Theme: Seasonal Processes
Every year seasonal carbon dioxide ice, known to us as “dry ice,” covers the poles of Mars. In the South Polar region this ice is translucent, allowing sunlight to pass through and warm the surface below. The ice then sublimes (evaporates) from the bottom of the ice layer, and carves channels in the surface.

The channels take on many forms. In the cutout the gas from the dry ice has etched wide shallow channels. This region is relatively flat, which may be the reason these channels have a different morphology than the “spiders” seen in more hummocky terrain.

This caption was featured in a December 2007 AGU presentation “Spring at the South Pole of Mars.”

Written by: Candy Hansen  (12 December 2007)

Acquisition date
15 April 2007

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
246.7 km (153.3 miles)

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

Map projected scale
25 cm/pixel

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Emission angle

Phase angle

Solar incidence angle
75°, with the Sun about 15° above the horizon

Solar longitude
219.6°, Northern Autumn

For non-map projected images
North azimuth:  139°
Sub-solar azimuth:  35.5°
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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.