Old Salt
Old Salt
ESP_025698_1485  Science Theme: Fluvial Processes
Nightime infrared images (from THEMIS on the Mars Odyssey spacecraft) show a meandering and branched channel-like form in this region. It is bright (warmer) at night, suggesting exposed bedrock rather than fine-grained materials.

This HiRISE image shows some patches of pinkish or purplish materials with a distinctive fracture pattern. These patches are very similar in color, morphology, and geologic setting to larger deposits thought to consist of chloride salts, like table salt (NaCl) except that the chlorine anion (Cl-) may be combined with another cation such as magnesium (Mg+) or potassium (K+) rather than sodium (Na+). Such chlorides form when salty water evaporates.

Written by: Alfred McEwen  (29 February 2012)
Acquisition date
19 January 2012

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
252.6 km (157.0 miles)

Original image scale range
50.6 cm/pixel (with 2 x 2 binning) so objects ~152 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
69°, with the Sun about 21° above the horizon

Solar longitude
59.2°, Northern Spring

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  49.9°
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   (283MB)

IRB color
map-projected   (178MB)

Black and white
map-projected  (144MB)
non-map           (173MB)

IRB color
map projected  (69MB)
non-map           (148MB)

Merged IRB
map projected  (267MB)

Merged RGB
map-projected  (259MB)

RGB color
non map           (149MB)
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.