Gullies on Pole-Facing Slope and Arcuate Ridges on Crater Floor
NASA/JPL-Caltech/UArizona
Gullies on Pole-Facing Slope and Arcuate Ridges on Crater Floor
ESP_011995_1410  Science Theme: Fluvial Processes
This Southern Hemisphere crater has gullies on its north and northeast walls. Gullies are proposed to be carved by liquid water originating from the subsurface or melting ice/snow on the surface.

Arcuate ridges, wave-shaped high-standing features, are located downslope of the gullies here. This happens frequently on Mars, although it is unknown whether the formation of gullies and arcuate ridges are related to each other.

Dark dunes are visible on the crater floor. Lighter, smaller dunes rim the south side of the crater floor. The entire scene has a pitted texture, suggesting that ground ice was once present in this region. When ground ice sublimates (goes from a solid directly to a gas), it leaves behind empty spaces in the soil that turn into pits as the remaining overlying soil collapses to fill them.

Written by: Kelly Kolb  (25 March 2009)

This is a stereo pair with ESP_012496_1410.
 
Acquisition date
16 February 2009

Local Mars time
15:56

Latitude (centered)
-38.823°

Longitude (East)
201.427°

Spacecraft altitude
254.4 km (158.1 miles)

Original image scale range
25.6 cm/pixel (with 1 x 1 binning) so objects ~77 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection
Equirectangular

Emission angle
5.7°

Phase angle
52.9°

Solar incidence angle
58°, with the Sun about 32° above the horizon

Solar longitude
210.8°, Northern Autumn

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  14.9°
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   (703MB)

IRB color
map-projected   (314MB)

JP2 EXTRAS
Black and white
map-projected  (331MB)
non-map           (404MB)

IRB color
map projected  (120MB)
non-map           (320MB)

Merged IRB
map projected  (175MB)

Merged RGB
map-projected  (167MB)

RGB color
non map           (318MB)
ANAGLYPHS
Map-projected, reduced-resolution
Full resolution JP2 download
Anaglyph 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.