Bright and Dark Slope Streaks
NASA/JPL/UArizona
Bright and Dark Slope Streaks
ESP_059261_1950  Science Theme: Mass Wasting Processes
Slope streaks are common in the tropics of Mars. Once thought to be caused by flowing water, most scientists now believe that they are avalanches of dust. They are typically darker than their surroundings and often fan outwards downslope. This suggests that the dust sediment is sticky, so that the avalanche broadens as it flows downhill.

Slope streaks are known to fade over time, but the slope streaks at this monitoring site in Arabia Terra go beyond that. Here, old slope streaks appear to be brighter than the surrounding terrain. A comparison between HiRISE images taken in 2008 and in 2019 shows very few changes in the dark and bright streaks.

We can see three new dark streaks in our more recent image. These were the only changes spotted among the hundreds of streaks observed in the monitoring site, suggesting that new streak formation and fading take place on time scales of at least decades.

Written by: Paul Geissler (narration: Tre Gibbs)  (21 September 2021)
 
Acquisition date
19 March 2019

Local Mars time
14:08

Latitude (centered)
14.969°

Longitude (East)
42.324°

Spacecraft altitude
276.2 km (171.7 miles)

Original image scale range
55.6 cm/pixel (with 2 x 2 binning) so objects ~167 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection
Equirectangular

Emission angle
5.6°

Phase angle
30.4°

Solar incidence angle
36°, with the Sun about 54° above the horizon

Solar longitude
357.8°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  342.3°
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   (234MB)

IRB color
map-projected   (116MB)

JP2 EXTRAS
Black and white
map-projected  (98MB)
non-map           (134MB)

IRB color
map projected  (40MB)
non-map           (129MB)

Merged IRB
map projected  (270MB)

Merged RGB
map-projected  (249MB)

RGB color
non map           (120MB)
BONUS
4K (TIFF)
8K (TIFF)
10K (TIFF)

BONUS (MP4)
HiClip mini HD

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/University of Arizona

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.