Seasonal Flows in the Central Mountains of Hale Crater
Seasonal Flows in the Central Mountains of Hale Crater
ESP_040170_1440  Science Theme: Mass Wasting Processes
Recurring slope lineae (RSL) are active flows on warm Martian slopes that were thought to have been caused by seeping water. One of the most active sites known on Mars in in the central peaks (uplifted mountains of deep bedrock) of Hale Crater.

This image shows RSL extending downhill from bedrock cliffs, mostly towards the northwest (upper left). This image was acquired in middle summer when RSL are most active in the southern mid latitudes.

The RSL in Hale have an unusually “reddish” color compared to most RSL, perhaps due to oxidized iron compounds, like rust. Since HiRISE color is shifted to infra-red wavelengths, they are actually especially bright the near-infrared just beyond the range of human vision.

The Hale RSL are also unusual because they began activity much earlier than most RSL sites in the middle southern latitudes and were well-developed in the early spring (see ESP_038073_1440). (Note: If seeping water had caused RSL in Hale Crater, it must have been rich in salts to lower its freezing point significantly below the freezing point of pure water. )

Written by: Alfred McEwen (narration: Tre Gibbs)  (8 April 2015)
Acquisition date
20 February 2015

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
256.7 km (159.5 miles)

Original image scale range
25.8 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

Emission angle

Phase angle

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

Solar longitude
294.9°, Northern Winter

For non-map projected images
North azimuth:  96°
Sub-solar azimuth:  15.5°
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   (491MB)

IRB color
map-projected   (290MB)

Black and white
map-projected  (218MB)
non-map           (285MB)

IRB color
map projected  (75MB)
non-map           (253MB)

Merged IRB
map projected  (120MB)

Merged RGB
map-projected  (112MB)

RGB color
non map           (239MB)
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.