Distal Rampart of Crater in Chryse Planitia
NASA/JPL/University of Arizona
Distal Rampart of Crater in Chryse Planitia
ESP_014417_1975  Science Theme: Impact Processes
Greek  Italian  Spanish 

WALLPAPER

800  1024
1152  1280
1440  1600
1920  2048
2560
Impact craters on Mars are kind of neat: many of them look very different than impact craters seen on the Moon or Mercury.

Fresh lunar and Mercurian craters have ejecta blankets that look a bit rough near the crater rims; around larger craters, long rays or chains of secondary craters radiate away from the crater rims. Some Martian craters are similar to these craters, but Mars also has a high proportion of craters with forms not found on the Moon or Mercury: rampart craters.

Rampart craters, also called fluidized-ejecta craters, have ejecta blankets that appear lobate, or rounded, and end in low ridges or ramparts, such as the ridge in this HiRISE image. Here you see the rampart at the edge of the ejecta blanket that comes from an approximately 16 kilometer (10 mile)-diameter crater, about 16 km (10 mi) to the east.

For years there has been a debate about whether these lobes and ramparts were formed by ejecta interacting with the thin Martian atmosphere, or whether they formed because volatiles (such as water or ice) in the subsurface were incorporated into the ejecta material excavated by the impact. The common consensus is now in favor of the volatile hypothesis. Because of this, rampart craters can be used to indicate the past presence of water or ice in the Martian crust.

Written by: Andrea Philippoff   (12 November 2009)

This is a stereo pair with ESP_014140_1975.

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
23 August 2009

Local Mars time:
14:19

Latitude (centered)
17.176°

Longitude (East)
311.644°

Range to target site
301.5 km (188.4 miles)

Original image scale range
60.3 cm/pixel (with 2 x 2 binning) so objects ~181 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection
Equirectangular

Emission angle:
21.9°

Phase angle:
30.0°

Solar incidence angle
46°, with the Sun about 44° above the horizon

Solar longitude
326.4°, Northern Winter

North azimuth:
96°

Sub-solar azimuth:
323.9°
JPEG
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

JP2
Black and white
map-projected   (462MB)

IRB color
map-projected   (176MB)

JP2 EXTRAS
Black and white
map-projected  (160MB)
non-map           (188MB)

IRB color
map projected  (61MB)
non-map           (184MB)

Merged IRB
map projected  (502MB)

Merged RGB
map-projected  (471MB)

RGB color
non map           (176MB)
ANAGLYPHS
Map-projected, reduced-resolution
Full resolution JP2 download
Anaglyph details page

ADDITIONAL INFORMATION
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products
HiView

NB
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

USAGE POLICY
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



Postscript
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.