Unusual Depression Near Elysium Mons
Unusual Depression Near Elysium Mons
PSP_005813_2150  Science Theme: Impact Processes
This unusual depression and the associated concentric rings are situated within an area thought to have been deposited as a mud flow. Due to the lack of a distinctive, raised rim or other impact-related features, this crater is thought to have formed by the loss of material below the surface and subsequent collapse, rather than by an impact from space.

The exact mechanism for the loss of material is not fully understood, although the missing material was likely water in some form. This feature is near a large volcano, so perhaps there were explosive magma-water interactions that violently removed the water and some magma, followed by surface collapse. Or, less violently, there could have been simple melting of subsurface ice and then collapse of the surface into the resulting void. The rays emanating from the depression suggest some amount of violence before the surface collapse that sprayed material far from the depression.

Some aspects of this and other, nearby features are similar to the collapse pits associated with Grímsvötn volcano in Iceland, which erupts beneath an ice-cap. However, there are no rays formed during the eruptions at Grímsvötn.

This anaglyph (or 3-D stereoscopic image, best viewed with red-blue stereo glasses) qualitatively shows the relative topography of and around the depression. Quantitative topographic information will be gleaned from a digital elevation model generated from this stereo pair. Such information will allow estimates of the volume loss and of the slopes of the ridges and tilted blocks that make up the concentric rings around the central depression. This information is essential in solving the mystery of this feature's origins.

The color image shows very little color variation. This suggests that most of the feature has been covered by material all of the same color, probably dust.

Written by: Moses  (28 November 2007)

This is a stereo pair with PSP_005879_2150.
Acquisition date
23 October 2007

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
296.5 km (184.3 miles)

Original image scale range
29.7 cm/pixel (with 1 x 1 binning) so objects ~89 cm across are resolved

Map projected scale
25 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
335.4°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  315.2°
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   (867MB)

IRB color
map-projected   (397MB)

Black and white
map-projected  (386MB)
non-map           (415MB)

IRB color
map projected  (131MB)
non-map           (312MB)

Merged IRB
map projected  (208MB)

Merged RGB
map-projected  (213MB)

RGB color
non map           (297MB)
Map-projected, reduced-resolution
Full resolution JP2 download
Anaglyph details page

DTM 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

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NASA/JPL/University of Arizona

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.