Possible Inverted Topography Landscape with Clay Minerals
Possible Inverted Topography Landscape with Clay Minerals
ESP_022077_2000  Science Theme: Future Exploration/Landing Sites
This site, near Mawrth Vallis is intriguing for several reasons. First of all, there are lots of little knobs and plateaus that may expose layers of sedimentary rock. As on Earth, sedimentary rock on Mars is expected to hold clues to the conditions under which it formed - clues to the past environment and climate.

Second, many of the larger, darker plateaus appear fairly round. Typically Mars' surface is pock-marked with round depressions of impact craters. However, these round areas are raised up relative to the surroundings. This may be an example of inverted topography, in which an impact depression may have become filled with material which was, or became, harder than the surrounding terrain, and thus was more resistant to later erosion. Example materials may be solidified molten rock created during the impact event, or sediments that hardened due to alteration by water ponding within the crater.

Third, clay minerals, called phyllosilicates, have been detected here by other spacecraft instruments. Clays are exciting because they indicate there was most likely water around here long ago. Determining which layers and knobs contain the clays, and how widespread they are, will help scientists determine how much water existed here and for how long.

This site has been deemed so interesting that it is under consideration for a visit by a future landed rover.

Written by: Patrick Russell  (11 May 2011)

This is a stereo pair with ESP_022367_2000.
Acquisition date
12 April 2011

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
281.8 km (175.2 miles)

Original image scale range
28.2 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
59°, with the Sun about 31° above the horizon

Solar longitude
272.7°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  317.9°
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   (870MB)

IRB color
map-projected   (356MB)

Black and white
map-projected  (379MB)
non-map           (465MB)

IRB color
map projected  (134MB)
non-map           (329MB)

Merged IRB
map projected  (232MB)

Merged RGB
map-projected  (224MB)

RGB color
non map           (332MB)
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.