Fan at Valley Mouth
Fan at Valley Mouth
PSP_010434_1575  Science Theme: Geologic Contacts/Stratigraphy
This image shows the intersection of a valley with the floor of a large impact crater. The valley appears to have transported sediment that was deposited on the crater floor when the flow slowed. As the eastern side of the lobate deposit appears to have been sheared off, it is possible that continuing flow from the valley eroded into its own deposits.

The deposit is noticeably different from the crater floor in HiRISE color, indicating that the valley transported different sediments. Since the large crater is shallow, likely due to infilling, this suggests that multiple sources of sediment and perhaps multiple deposition processes have affected the geology at this site.

The deposited material in the lobe at the valley mouth displays some interesting textural features. Small boulders are commonly present on its surface. This may demonstrate relatively energetic deposition as in a flash flood, although it is possible that the boulders are superimposed debris from later impact craters.

The southern end of the deposit is also fracturing into blocks or slabs. These could be relics of old mud cracks, or of thermal contraction cracks formed in permafrost.

Written by: Colin Dundas  (7 January 2009)

This is a stereo pair with ESP_045431_1575.
Acquisition date
17 October 2008

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
258.9 km (160.9 miles)

Original image scale range
25.9 cm/pixel (with 1 x 1 binning) so objects ~78 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

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

Solar longitude
143.2°, Northern Summer

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  34.1°
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   (535MB)

IRB color
map-projected   (239MB)

Black and white
map-projected  (207MB)
non-map           (341MB)

IRB color
map projected  (63MB)
non-map           (247MB)

Merged IRB
map projected  (125MB)

Merged RGB
map-projected  (127MB)

RGB color
non map           (240MB)
Map-projected, reduced-resolution
Full resolution JP2 download
Anaglyph details page

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/JPL/University of Arizona

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.