Happy Face Swiss Cheese
Happy Face Swiss Cheese
ESP_020746_0945  Science Theme: Climate Change
HiRISE monitors the residual carbon dioxide cap on (or near) the South Pole of Mars to see how it changes over time.

Some of this terrain contains many pits, earning it the nickname “Swiss cheese terrain.” One of our monitoring spots is over what looks like a deranged happy face. If you look closely, you’ll see many changes since the first HiRISE image, PSP_004000_0945, was acquired in 2007. The pits have grown larger! When this pit growth was first discovered, it was suggested to be an indication of climate change on Mars.

However, we now suspect that the carbon dioxide that sublimates (going directly from a solid to a gas) from the pit walls recondenses on the nearby surfaces, so there is no net change in the carbon dioxide. With HiRISE stereo data we can measure these changes to test the theories.

Written by: Alfred McEwen  (26 January 2011)
Acquisition date
30 December 2010

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
247.6 km (153.9 miles)

Original image scale range
24.8 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
79°, with the Sun about 11° above the horizon

Solar longitude
207.7°, Northern Autumn

For non-map projected images
North azimuth:  174°
Sub-solar azimuth:  33.5°
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   (484MB)

IRB color
map-projected   (225MB)

Black and white
map-projected  (235MB)
non-map           (262MB)

IRB color
map projected  (72MB)
non-map           (239MB)

Merged IRB
map projected  (100MB)

Merged RGB
map-projected  (94MB)

RGB color
non map           (204MB)
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.