Crater Partially Exhumed by Sublimation in Amphitrites Patera
NASA/JPL-Caltech/UArizona
Crater Partially Exhumed by Sublimation in Amphitrites Patera
PSP_005632_1225  Science Theme: Climate Change
The terrain in this image is located in Amphitrites Patera, southwest of Hellas Basin. This area constitutes the interior of an ancient impact crater that was filled by a layer of smooth material, possibly composed of ash and dust, mixed with interstitial ice (ice filling spaces between dust and ash grains).

The curved ridge toward the top of the image is a remnant of the crater rim that was exhumed by erosion of the filling material. The morphology (appearance and shape) of the small, scalloped depressions, which we observe within the smooth material, suggests that the erosion process was sublimation (the process of a material going directly from a solid state to a gaseous state).

Scalloped depressions are a typical feature of the mid-latitudes of Mars between 40 and 60 degrees latitude. They usually have a steep
pole-facing scarp (cliff), displaying series of small pits and fractures and a gentler, smoother, equator-facing slope. This asymmetry is most likely due to differences in solar heating. The large scalloped depressions appear to have formed from the coalescing of multiple, smaller scalloped depressions. Their formation may be an ongoing process, although no definitive evidence has been uncovered so far.


Written by: Alexandra Lefort  (5 December 2007)

This is a stereo pair with PSP_005342_1225.
 
Acquisition date
09 October 2007

Local Mars time
14:21

Latitude (centered)
-57.299°

Longitude (East)
54.314°

Spacecraft altitude
249.1 km (154.8 miles)

Original image scale range
51.4 cm/pixel (with 2 x 2 binning) so objects ~154 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection
Equirectangular

Emission angle
15.2°

Phase angle
62.5°

Solar incidence angle
52°, with the Sun about 38° above the horizon

Solar longitude
327.7°, Northern Winter

For non-map projected images
North azimuth:  96°
Sub-solar azimuth:  50.2°
JPEG
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

JP2
Black and white
map-projected   (410MB)

IRB color
map-projected   (206MB)

JP2 EXTRAS
Black and white
map-projected  (165MB)
non-map           (251MB)

IRB color
map projected  (69MB)
non-map           (212MB)

Merged IRB
map projected  (445MB)

Merged RGB
map-projected  (416MB)

RGB color
non map           (199MB)
ANAGLYPHS
Map-projected, reduced-resolution
Full resolution JP2 download
Anaglyph details page

DIGITAL TERRAIN MODEL (DTM)
DTM details page

ADDITIONAL INFORMATION
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products
HiView

NB
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

USAGE POLICY
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/JPL-Caltech/UArizona

POSTSCRIPT
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.