Crater on the North Polar Layered Deposits
Crater on the North Polar Layered Deposits
PSP_009663_2635  Science Theme: Polar Geology
The north polar layered deposits, and the bright ice cap that covers them, are very young (by geologic standards) features. To try and figure out the age of an area, or how quickly it's being resurfaced, planetary scientists count up the number of craters at different sizes. An older surface has more time to accumulate more craters whereas a younger surface, or one that has a lot of geologic activity that destroys craters, doesn't have many impact craters.

These polar deposits have a very low crater count so it is possible that the ice cap (bright white in this image) might only by about 10,000 years old and the surface of the layered deposits (orange-brown in this image) may be only a few million years old. This sounds like a long time but is very short compared to other surfaces on Mars.

HiRISE is enabling a more detailed study of these polar craters and the target of this observation is visible in the center of the image. This crater proved to be a surprise in a few ways. Its shape is non-circular which is quite unusual for an impact crater. One possibility is that flow of the ice beneath the surrounding terrain has deformed the crater; however, ice-flow rates are thought to be very low on Mars today.

The crater also contains a patch of bright ice despite being surrounded by terrain that has mostly lost its ice cover. This seems typical for these polar craters and it may be that ice within these craters is protected from ablation by shading from the crater walls.

Written by: Shane Byrne  (15 October 2008)
Acquisition date
18 August 2008

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
319.0 km (198.2 miles)

Original image scale range
31.9 cm/pixel (with 1 x 1 binning) so objects ~96 cm across are resolved

Map projected scale
25 cm/pixel

Map projection

Emission angle

Phase angle

Solar incidence angle
62°, with the Sun about 28° above the horizon

Solar longitude
114.4°, Northern Summer

For non-map projected images
North azimuth:  114°
Sub-solar azimuth:  323.1°
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   (621MB)

IRB color
map-projected   (279MB)

Black and white
map-projected  (312MB)
non-map           (242MB)

IRB color
map projected  (97MB)
non-map           (215MB)

Merged IRB
map projected  (191MB)

Merged RGB
map-projected  (176MB)

RGB color
non map           (184MB)
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.