Gullies and Craters and Dunes, Oh My!
Gullies and Craters and Dunes, Oh My!
ESP_050111_1305  Science Theme: Mass Wasting Processes
This unnamed, approximately 30-kilometer diameter crater, formed in the Southern highlands of Mars. Our image shows regions of geologic diversity within, making this an interesting spot for scientists to study how different Martian processes interact with each other.

Gullies, or channels formed by fluids such as water or lava, cut into the rim and sides of this crater. The presence of gullies can reveal clues about the ancient history of Mars, such as the amount of flowing fluid needed to form them and roughly how long ago that happened. This crater may also host features actively changing on the surface of Mars known as “recurring slope lineae” (RSL). Manifesting as dark streaks on steep slopes such as the walls of craters, scientists posit briny flows of small volumes of water as a possible RSL formation method. Studying the behavior of RSL further may provide evidence for the presence of water on Mars today.

Moving toward the crater floor, one can observe patterns indicative of dunes. Dunes arise from the breakdown of exposed rocks by wind and subsequent manipulation of the eroded sand particles into wave-like structures. The presence of dust devil tracks provides additional evidence for significant wind activity at this location. These dunes are very dusty and so likely haven't been active (moved) in some time.

HiRISE also captured a small, relatively fresh crater on the floor near the dunes. One of the most ubiquitous processes in the solar system, impact cratering can drastically change the surface of a planetary body. As such, craters provide sources of comparison between planets, moons, and other bodies across the solar system. Impacts still occur today, helping scientists find relative ages of different areas of a planet and discover materials buried under the surface.

All of these processes have altered the surface of Mars in the past and continue to do so today. Since gully formation, wind erosion, and impact cratering could have interacted with each other for many years, planetary scientists find it difficult to work backwards and make definitive statements about ancient Martian history. However, HiRISE imagery has aided in closing these gaps in our scientific knowledge.

Written by: Nicole Bardabelias (audio: Tre Gibbs)  (2 June 2017)
Acquisition date
05 April 2017

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
252.7 km (157.1 miles)

Original image scale range
25.5 cm/pixel (with 1 x 1 binning) so objects ~76 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
52°, with the Sun about 38° above the horizon

Solar longitude
344.5°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  50.3°
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   (809MB)

IRB color
map-projected   (447MB)

Black and white
map-projected  (352MB)
non-map           (495MB)

IRB color
map projected  (143MB)
non-map           (405MB)

Merged IRB
map projected  (208MB)

Merged RGB
map-projected  (198MB)

RGB color
non map           (400MB)

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.