Clustered Impact Features
Clustered Impact Features
PSP_008571_1995  Science Theme: Impact Processes
Nili Fossae is a region that is thought to be approximately 3.5 billion years in age and, based on results from Omega, is the largest exposure of olivine (a common dark colored rock forming mineral found in igneous rocks) on the surface of Mars. The many fractures and grabens (depressed blocks of crust resulting from extension) that make up the region are believed to be the result of the Isidis impact basin.

Of particular interest are the two impact clusters found midway down this image. Each cluster is approximately 100 meters in diameter. The exact origin of such features is not known. It is thought that they are the result of a loosely conglomerated, stony meteoroid that broke apart during descent through the Martian atmosphere.

Written by: Shawn Hart  (2 July 2008)
Acquisition date
25 May 2008

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
281.5 km (175.0 miles)

Original image scale range
28.4 cm/pixel (with 1 x 1 binning) so objects ~85 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
44°, with the Sun about 46° above the horizon

Solar longitude
76.5°, Northern Spring

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  21.3°
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non-map           (494MB)

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B&W label
Color label
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EDR products

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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.