How Old are Martian Gullies?
NASA/JPL-Caltech/UArizona
How Old are Martian Gullies?
PSP_002293_1450  Science Theme: Fluvial Processes
Gullies eroded into the steep inner slope of an impact crater at this location appear perfectly pristine. Although at first glance it may appear that there are craters superimposed on the gully fans, inspection of HiRISE stereo coverage shows that the craters lie only on the pre-gully terrain.

Distinctive colors in the gully channels and alcoves offer another indication of youth and recent activity. The pre-gully landscape is covered by secondary craters from nearby Gasa Crater, estimated to be about 1 million years old. Although some have suggested that the Martian gullies are also about a million years old and formed in a different environment, we now know that they are continuing to form today.

Written by: Alfred McEwen  (24 April 2017)
 
Acquisition date
22 January 2007

Local Mars time
15:49

Latitude (centered)
-34.767°

Longitude (East)
130.996°

Spacecraft altitude
252.9 km (157.2 miles)

Original image scale range
50.8 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
Equirectangular

Emission angle
4.9°

Phase angle
62.3°

Solar incidence angle
66°, with the Sun about 24° above the horizon

Solar longitude
170.7°, Northern Summer

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  29.9°
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   (115MB)

IRB color
map-projected   (68MB)

JP2 EXTRAS
Black and white
map-projected  (47MB)
non-map           (71MB)

IRB color
map projected  (16MB)
non-map           (70MB)

Merged IRB
map projected  (108MB)

Merged RGB
map-projected  (106MB)

RGB color
non map           (64MB)
BONUS
4K (TIFF)
8K (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-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.