Pits near Medusae Sulci
Pits near Medusae Sulci
ESP_080844_1735  Science Theme: Aeolian Processes
This image shows numerous C-shaped depressions within the Medusae Fossae Formation, which is interpreted to consist of volcanic ash. The center of most depressions contains a small hill, which provides a vital clue to how the depressions formed.

These pits may have formed when wind blowing across the ground surface encounters an obstacle (the small hill) that redirects the wind and causes it to start blowing away some of the volcanic ash in front of and to the side of the obstacle. This results in these C-shaped depressions that we now see.

Written by: Chris Okubo  (13 February 2024)

Acquisition date
25 October 2023

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
265.8 km (165.2 miles)

Original image scale range
from 26.9 cm/pixel (with 1 x 1 binning) to 53.7 cm/pixel (with 2 x 2 binning)

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
61°, with the Sun about 29° above the horizon

Solar longitude
138.4°, Northern Summer

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  29.2°
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   (387MB)

IRB color
map-projected   (170MB)

Black and white
map-projected  (166MB)
non-map           (282MB)

IRB color
map projected  (54MB)
non-map           (132MB)

Merged IRB
map projected  (128MB)

Merged RGB
map-projected  (126MB)

RGB color
non map           (130MB)
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.