Muddy Ejecta Flow
Muddy Ejecta Flow
ESP_046843_1940  Science Theme: Impact Processes
This small 2 kilometer-wide crater was sitting around, minding its own business when a meteoroid struck the ground just to the west and created a new, larger crater almost 10 kilometers in diameter (not pictured).

The ejecta spraying out of the new crater landed back on the ground and then continued to flow away from the new crater, and the smaller crater was in the way of that muddy flow. You can see where much of the muddy material flowed around the crater’s uplifted rim and forms a squiggly ridge, but you can also see where the mud flow slid over the rim and ponded down in the bottom of the crater.

One question we don’t know the answer to is: “how wet was the muddy ejecta?” Ongoing observations like this and laboratory-based experiments are trying to find the answer to that question.

This image also illustrates a common theme in geology, namely, the law of superposition. Because the crater has been affected by ejecta from the larger crater to the west, the small crater had to be there first and then the second, larger crater and its ejecta had to form. This allows planetary geologists to decipher the relative ages of different landforms. Because a central goal of geology is to understand past events from present-day clues, geology is sometimes compared to forensic science.

Written by: Kirby Runyon (audio: Tre Gibbs)  (10 January 2017)

This is a stereo pair with ESP_037612_1940.
Acquisition date
24 July 2016

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
275.4 km (171.2 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

Emission angle

Phase angle

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

Solar longitude
191.4°, Northern Autumn

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  349.4°
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   (196MB)

IRB color
map-projected   (108MB)

Black and white
map-projected  (86MB)
non-map           (107MB)

IRB color
map projected  (33MB)
non-map           (103MB)

Merged IRB
map projected  (203MB)

Merged RGB
map-projected  (188MB)

RGB color
non map           (97MB)
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.