Knob in the South Polar Layered Deposits of Mars
Knob in the South Polar Layered Deposits of Mars
ESP_032020_0955  Science Theme: Polar Geology
The south polar layered deposits of Mars are a thick stack of layers of ice and dust, deposited over millions of years. The rate of deposition changes over time, and in some times and places the stack is eroded.

Here, a low mesa or ring of hills occurs near the edge of the layered deposits. It is likely that this feature was once an impact crater. The floor of the crater became resistant, and was left behind as the rest of the surface eroded.

Images like this one can show us where the layered deposits are being eroded, and how much ice and dust has been lost. This, in turn, helps us understand the history recorded in the layers.

Written by: Colin Dundas  (10 July 2013)

This is a stereo pair with ESP_023066_0955.
Acquisition date
26 May 2013

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
247.4 km (153.8 miles)

Original image scale range
49.9 cm/pixel (with 2 x 2 binning) so objects ~150 cm across are resolved

Map projected scale
50 cm/pixel

Map projection

Emission angle

Phase angle

Solar incidence angle
74°, with the Sun about 16° above the horizon

Solar longitude
325.1°, Northern Winter

For non-map projected images
North azimuth:  124°
Sub-solar azimuth:  56.6°
Black and white
map projected  non-map

IRB color
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Merged IRB
map projected

Merged RGB
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RGB color
non-map projected

Black and white
map-projected   (105MB)

IRB color
map-projected   (58MB)

Black and white
map-projected  (49MB)
non-map           (71MB)

IRB color
map projected  (20MB)
non-map           (67MB)

Merged IRB
map projected  (107MB)

Merged RGB
map-projected  (101MB)

RGB color
non map           (63MB)
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.