HiRISE | Gullies in Dao Vallis (PSP_006659

NASA/JPL-Caltech/UArizona

Gullies in Dao Vallis
PSP_006659_1460 Science Theme: Fluvial Processes

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Gullies on the northwest side of Dao Vallis, a Martian outflow channel, are the focus of this observation. The outflow channels are thought to have been carved by gigantic, ancient floods.

Gullies are largely thought to be the result of water flow, but the origin of the water is much debated. One theory proposes that melting snowpack, or a mantling (blanketing) unit, forms gullies. Such a mantling unit is visible here between some of the gullies, in the full high-resolution image. Some alcove-shaped features appear to have mantling material in them. If the mantling unit is indeed related to gully formation, then gullies are potentially forming here.

Written by: Kelly Kolb (27 February 2008)

Acquisition date
28 December 2007

Local Mars time
14:36

Latitude (centered)
-33.889°

Longitude (East)
92.057°

Spacecraft altitude
255.3 km (158.7 miles)

Original image scale range
25.5 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
0.6°

Phase angle
52.6°

Solar incidence angle
53°, with the Sun about 37° above the horizon

Solar longitude
9.2°, Northern Spring

For non-map projected images
North azimuth: 97°
Sub-solar azimuth: 43.4°

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   (677MB)

IRB color
map-projected   (299MB)

JP2 EXTRAS
Black and white
map-projected (284MB)
non-map           (420MB)

IRB color
map projected (98MB)
non-map           (301MB)

Merged IRB
map projected (146MB)

Merged RGB
map-projected (149MB)

RGB color
non map           (296MB)

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.