South Polar Residual Cap Margin in Enhanced Color
South Polar Residual Cap Margin in Enhanced Color
PSP_005571_0950  Science Theme: Polar Geology
This scene is about 2.7 kilometers (approximately 1.7 miles) long and shows part of the edge of the south polar residual cap in enhanced color. Illumination is from the lower right.

The relatively bright, grayish areas are the residual cap, and the darker, reddish areas are mostly likely covered by dust. The south polar residual cap is made, for the most part, of carbon dioxide ice (commonly called "dry ice") and dust, with a little water ice in some places.

In the subimage, one can see fractures in the residual cap ice near the margin and, farther in, circular depressions that, in some places, appear to have coalesced. These depressions constitute what is called "Swiss cheese terrain." and it's fairly easy to see why. The Swiss cheese terrain is created when the carbon dioxide goes directly from the solid state (ice) to a gaseous state (the more familiar carbon dioxide gas) as temperatures warm during south polar summer. Swiss cheese formation may also be linked in a complicated way to the behavior of major Martian dust storms.

Images like these, taken before and after dust storm events, can aid our understanding of that complicated relationship.

Written by: Kathryn Fishbaugh  (28 November 2007)

This is a stereo pair with PSP_005466_0950.
Acquisition date
04 October 2007

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
246.7 km (153.3 miles)

Original image scale range
25.5 cm/pixel (with 1 x 1 binning) so objects ~76 cm across are resolved

Map projected scale
25 cm/pixel

Map projection

Emission angle

Phase angle

Solar incidence angle
73°, with the Sun about 17° above the horizon

Solar longitude
325.1°, Northern Winter

For non-map projected images
North azimuth:  109°
Sub-solar azimuth:  56.3°
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   (869MB)

IRB color
map-projected   (465MB)

Black and white
map-projected  (476MB)
non-map           (484MB)

IRB color
map projected  (178MB)
non-map           (454MB)

Merged IRB
map projected  (199MB)

Merged RGB
map-projected  (195MB)

RGB color
non map           (391MB)
Map-projected, reduced-resolution
Full resolution JP2 download
Anaglyph details page

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.