Unconformity in North Polar Layered Deposits
Unconformity in North Polar Layered Deposits
PSP_009390_2595  Science Theme: Polar Geology
This image features the North Polar layered deposits. The flat tongue-shaped feature at the bottom of the image is the surface of the cap.

The bright textured region near the top of the image is polygonal ground, which is commonly found in the Martian high-latitudes. Polygonal ground formation is thought to relate to temperature cycles in ice-rich soil.

Just south of the polygonal ground, a bright layer within the cap can be seen eroding in the form of landslides, particularly near the center of the image.

The most noticeable part of the polar cap is visible in an unconformity, the horizontal break in the cap layers. An unconformity is caused by non-uniform erosion or deposition. In this case, non-uniform erosion or deposition might have occurred due to variable climate over geologic time.

Written by: Kelly Kolb  (1 October 2008)
Acquisition date
28 July 2008

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
318.5 km (197.9 miles)

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

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25 cm/pixel

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Solar incidence angle
57°, with the Sun about 33° above the horizon

Solar longitude
104.7°, Northern Summer

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North azimuth:  106°
Sub-solar azimuth:  324.8°
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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.