PDS logoPlanetary Data System
PDS Information
Find a Node - Use these links to navigate to any of the 8 publicly accessible PDS Nodes.

This bar indicates that you are within the PDS enterprise which includes 6 science discipline nodes and 2 support nodes which are overseen by the Project Management Office at NASA's Goddard Space Flight Center (GSFC). Each node is led by an expert in the subject discipline, supported by an advisory group of other practitioners of that discipline, and subject to selection and approval under a regular NASA Research Announcement.
Click here to return to the Photojournal Home Page Click here to view a list of Photojournal Image Galleries Photojournal_inner_header
Latest Images  |  Spacecraft & Technology  |  Animations  |  Space Images App  |  Feedback  |  Photojournal Search  

PIA22454: Twin Craters in Meridiani Planum
This image from NASA's Mars Reconnaissance Orbiter (MRO) shows two small impact craters located in Meridiani Planum on Mars. Small boulders on the floor and walls of the left-side crater.
 Target Name:  Mars
 Is a satellite of:  Sol (our sun)
 Mission:  Mars Reconnaissance Orbiter (MRO) 
 Spacecraft:  Mars Reconnaissance Orbiter (MRO)
 Instrument:  HiRISE 
 Product Size:  2880 x 1800 pixels (w x h) 
 Produced By:  University of Arizona/HiRISE-LPL 
 Other  
Information: 		 Other products from ESP_050849_1700 
 Full-Res TIFF:  PIA22454.tif (5.033 MB)
 Full-Res JPEG:  PIA22454.jpg (885.9 kB)  

Click on the image above to download a moderately sized image in JPEG format (possibly reduced in size from original)

Original Caption Released with Image:

Click here for larger image of PIA22454
Map Projected Browse Image
Click on image for larger version
The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel.
[The original image scale is 27.4 centimeters (10.8 inches) per pixel (with 1 x 1 binning); objects on the order of 82 centimeters (32.3 inches) across are resolved.] North is up.

This image from NASA's Mars Reconnaissance Orbiter (MRO) shows two small impact craters located in Meridiani Planum. This is an example of the geologic principle of superposition: figuring out what happened first by looking at how features interact with each other. We can see that one of the craters must have hit the surface after the other was already there, but which came first?

We can see that the ejecta blankets look rougher on the right side of the image than they do on the left. This could mean that the right side ejecta is newer, and has not been exposed to the wind as much as the left side has.

Zooming in, we see small boulders on the floor and walls of the left-side crater, and they even seem to match the rough material in the ejecta on the right. With these clues, we can hypothesize that the crater on the left was here first. After some time another asteroid hit, formed the crater on the right, which threw material onto the floor of the left, where it remains to this day.

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.

Image Credit:
NASA/JPL-Caltech/Univ. of Arizona

Image Addition Date:
2018-05-14