Ancient Rivers
NASA/JPL/UArizona
Ancient Rivers
ESP_070975_2060  Science Theme: Sedimentary/Layering Processes
Billions of years ago, a river flowed across this scene in Mawrth Vallis. Like on Earth, these river beds can get filled up with rocks that are cemented together. After Mars became a colder, drier place and the river disappeared, the rocky river bed remained.

In this HiRISE image, we see a dark ridge snaking across the surface. The dark ridge is the old river bed. It is raised above its surroundings now because these softer surroundings have been eroded away, whereas the rocky river bed resists that. Scientists call these ridges inverted channels and many of them are visible in this area of Mars.

Written by: Shane Byrne (narration: Tre Gibbs)  (13 December 2021)

This is a stereo pair with ESP_071041_2060.
 
Acquisition date
16 September 2021

Local Mars time
15:29

Latitude (centered)
25.905°

Longitude (East)
341.441°

Spacecraft altitude
286.1 km (177.8 miles)

Original image scale range
59.1 cm/pixel (with 2 x 2 binning) so objects ~177 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection
Equirectangular

Emission angle
14.1°

Phase angle
60.6°

Solar incidence angle
47°, with the Sun about 43° above the horizon

Solar longitude
100.1°, Northern Summer

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  17.6°
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   (231MB)

IRB color
map-projected   (138MB)

JP2 EXTRAS
Black and white
map-projected  (112MB)
non-map           (141MB)

IRB color
map projected  (45MB)
non-map           (111MB)

Merged IRB
map projected  (237MB)

Merged RGB
map-projected  (217MB)

RGB color
non map           (102MB)
ANAGLYPHS
Map-projected, reduced-resolution
Full resolution JP2 download
Anaglyph details page

BONUS
4K (TIFF)
8K (TIFF)
10K (TIFF)

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/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.