Dry Ice Gone Wild
Dry Ice Gone Wild
ESP_020914_0930  Science Theme: Seasonal Processes
Have you ever played with dry ice (with leather gloves on of course!)? Perhaps you've made Halloween punch? Set a spooky scene? The fun comes from the fact that dry ice goes directly from solid to vapor, unlike water ice which melts into liquid when it gets warm.

On Mars the seasonal polar caps are composed of dry ice (carbon dioxide). In the springtime as the sun shines on the ice, it turns from solid to gas and causes erosion of the surface. I enjoy the incredible diversity of forms that the erosion takes, and am studying the factors that give us “spiders”, “caterpillars”, or “starbursts”, all colloquial words for what we rigorously name “araneiform” terrain.

This particular example shows eroded channels filled with bright ice, in contrast to the muted red of the underlying ground. In the summer the ice will disappear into the atmosphere, and we will see just the channels of ghostly spiders carved in the surface. This is truly Martian terrain—this type of erosion does not take place anywhere naturally on Earth because our climate is too warm.

Written by: Candy Hansen  (21 March 2011)
Acquisition date
12 January 2011

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
245.1 km (152.3 miles)

Original image scale range
from 24.5 cm/pixel (with 1 x 1 binning) to 49.0 cm/pixel (with 2 x 2 binning)

Map projected scale
25 cm/pixel

Map projection

Emission angle

Phase angle

Solar incidence angle
77°, with the Sun about 13° above the horizon

Solar longitude
215.7°, Northern Autumn

For non-map projected images
North azimuth:  220°
Sub-solar azimuth:  34.4°
Black and white
map projected  non-map

IRB color
map projected  non-map

Merged IRB
map projected

Merged RGB
map projected

RGB color
non-map projected

Black and white
map-projected   (370MB)

IRB color
map-projected   (210MB)

Black and white
map-projected  (187MB)
non-map           (161MB)

IRB color
map projected  (86MB)
non-map           (235MB)

Merged IRB
map projected  (105MB)

Merged RGB
map-projected  (96MB)

RGB color
non map           (207MB)
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’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.