Mystery Martian Morphology of the Month
Mystery Martian Morphology of the Month
ESP_031268_2115  Science Theme: Tectonic Processes
This image covers many shallow irregular pits with raised rims, concentrated along ridges and other topographic features. How did these odd features form?

One idea is that they could be from sublimation of shallow lenses of nearly pure ice, but why do the pits have raised rims? They can’t be impact craters with such fortuitous alignment and irregular margins. They aren’t wind-blown deposits because there are many boulders, too big to be moved by the wind. There are younger wind-blown drifts on top of the pits, and there's no clear connection to volcanism.

Some speculate that there were ancient oceans over this region—could that somehow explain these features? Ancient glaciation is another possibility, perhaps depositing ice-rich debris next to topographic obstacles. Future images of this region may provide clues, but for now this is a mystery.

Written by: Alfred McEwen  (1 May 2013)
Acquisition date
28 March 2013

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
293.4 km (182.4 miles)

Original image scale range
58.8 cm/pixel (with 2 x 2 binning) so objects ~176 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
64°, with the Sun about 26° above the horizon

Solar longitude
290.8°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  312.0°
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   (248MB)

IRB color
map-projected   (137MB)

Black and white
map-projected  (108MB)
non-map           (130MB)

IRB color
map projected  (43MB)
non-map           (122MB)

Merged IRB
map projected  (266MB)

Merged RGB
map-projected  (245MB)

RGB color
non map           (115MB)
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

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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.