Swiss Cheese on a Red Planet
Swiss Cheese on a Red Planet
ESP_056310_0940  Science Theme: Climate Change
The Martian south polar cap is a layer of carbon dioxide ice, full of pits that make it look like Swiss cheese. The pits form when the Sun heats the ice and makes it sublimate (transform from a solid to a gas). Because it’s at the pole, the Sun never gets very high in the sky, so steep slopes get more heat and sublimate faster, causing pits to form and grow. This is balanced by new carbon dioxide frost that forms on flatter areas.

Compare this image with one we took in 2007. How many differences can you find?

Written by: Colin Dundas  (10 December 2018)
Acquisition date
01 August 2018

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
246.5 km (153.2 miles)

Original image scale range
24.7 cm/pixel (with 1 x 1 binning) so objects ~74 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
222.0°, Northern Autumn

For non-map projected images
North azimuth:  127°
Sub-solar azimuth:  38.1°
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   (931MB)

IRB color
map-projected   (526MB)

Black and white
map-projected  (579MB)
non-map           (642MB)

IRB color
map projected  (258MB)
non-map           (561MB)

Merged IRB
map projected  (221MB)

Merged RGB
map-projected  (198MB)

RGB color
non map           (493MB)
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.