Which Crater Came First?
NASA/JPL/University of Arizona
Which Crater Came First?
ESP_020190_1690  Science Theme: Impact Processes
Arabic  French  Italian  Spanish  Russian  Turkish 


720p (MP4)
Listen to the text


800  1024
1152  1280
1440  1600
1920  2048
2560  2880


PDF, 11 x 17 in


This image shows two craters, both approximately the same diameter (not quite 3 kilometers, or about 1.8 miles), but quite different in appearance otherwise.

The slightly smaller crater to the south seems to have a sharper rim and steeper sides than its partner to the north, which also appears to contain more small craters inside it and along its rim. The interior of the northern crater, in particular its south-facing wall, appears to have a similar texture to the ejecta around the southern crater. This is the second image in a stereo pair (the first is ESP_019346_1690), so we have an anaglyph of these craters.

Although it would require a digital terrain model and more analysis to be certain, in the anaglyph it appears that the southern crater has a higher rim and a deeper center than the northern crater. All these signs point to the northern crater being quite a bit older than the southern crater, rather than the two craters forming in the same impact event. For an example of two craters that might have formed at the same time (see ESP_020894_1395).

Compare the similarity of those two craters with the disparate appearance of the ones in this image.

Written by: Nicole Baugh (audio by Tre Gibbs)   (13 June 2012)

This is a stereo pair with ESP_019346_1690.

Click to share this post on Twitter Click to share this post on Facebook Click to share this post on Google+ Click to share this post on Tumblr
Acquisition date
16 November 2010

Local Mars time:

Latitude (centered)

Longitude (East)

Range to target site
272.8 km (170.5 miles)

Original image scale range
54.6 cm/pixel (with 2 x 2 binning) so objects ~164 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection

Emission angle:

Phase angle:

Solar incidence angle
57°, with the Sun about 33° above the horizon

Solar longitude
182.3°, Northern Autumn

North azimuth:

Sub-solar azimuth:
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   (402MB)

IRB color
map-projected   (205MB)

Black and white
map-projected  (209MB)
non-map           (193MB)

IRB color
map projected  (81MB)
non-map           (201MB)

Merged IRB
map projected  (393MB)

Merged RGB
map-projected  (355MB)

RGB color
non map           (185MB)
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/JPL/University of Arizona

For information about NASA and agency programs on the Web, visit: http://www.nasa.gov. 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. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. The image data were processed using the U.S. Geological Survey’s ISIS3 software.