Radial Channels Carved by Dry Ice
Radial Channels Carved by Dry Ice
ESP_014413_0930  Science Theme: Seasonal Processes
Mars’ carbon dioxide atmosphere partially condenses every winter to form polar caps of dry ice. In the spring, the evaporation of the ice is a dynamic process and carves channels into the ground as it escapes back into the atmosphere.

Often these channels are radial in nature, and are colloquially refered to as “spiders,” although the prefered term for these radially-organized channels is “araneiform” which means spider-like.

In this cutout all the seasonal frost is gone, and we can use stereo images or shadow measurements to measure the depth of the channels carved into the ground, typically 1 to 2 meters deep.

Written by: Candy Hansen  (30 September 2009)

This is a stereo pair with ESP_014282_0930.
Acquisition date
23 August 2009

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
246.2 km (153.0 miles)

Original image scale range
53.5 cm/pixel (with 2 x 2 binning) so objects ~161 cm across are resolved

Map projected scale
50 cm/pixel

Map projection

Emission angle

Phase angle

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

Solar longitude
326.2°, Northern Winter

For non-map projected images
North azimuth:  107°
Sub-solar azimuth:  57.9°
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Black and white
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non-map           (157MB)

IRB color
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non-map           (135MB)

Merged IRB
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RGB color
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Black & white is 5 km across; enhanced color about 1 km
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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.