Disappearing Boulder Tracks
Disappearing Boulder Tracks
ESP_026055_1985  Science Theme: Mass Wasting Processes
This image was taken in February 2012, in order to compare against image ESP_017985_1985, which was acquired in May 2010. These two images are separated by approximately one Mars year.

The original image showed a prominent series of dark markings that are the tracks left by boulders as they rolled and bounced down the slope. As they do this, they set off miniature dust avalanches. The bright, fine dust slides away, leaving a darker, larger grained dust underneath.

This follow-up image shows that the smaller dark tracks are gone, and the larger ones have faded considerably. This is most likely due to the fine bright dust that is transported in the atmosphere falling down and re-covering the dark markings.

Written by: Ross A. Beyer  (18 April 2012)
Acquisition date
16 February 2012

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
281.7 km (175.1 miles)

Original image scale range
28.5 cm/pixel (with 1 x 1 binning) so objects ~86 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

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

Solar longitude
71.4°, Northern Spring

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  20.8°
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   (959MB)

IRB color
map-projected   (529MB)

Black and white
map-projected  (513MB)
non-map           (465MB)

IRB color
map projected  (203MB)
non-map           (438MB)

Merged IRB
map projected  (228MB)

Merged RGB
map-projected  (234MB)

RGB color
non map           (395MB)
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’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.