Well-Preserved Impact Ejecta and Impact Melt-Rich Deposits in Terra Sabaea
NASA/JPL-Caltech/UArizona
Well-Preserved Impact Ejecta and Impact Melt-Rich Deposits in Terra Sabaea
ESP_047735_1610  Science Theme: Impact Processes
This image of a well-preserved unnamed elliptical crater in Terra Sabaea, is illustrative of the complexity of ejecta deposits forming as a by-product of the impact process that shapes much of the surface of Mars.

Here we see a portion of the western ejecta deposits emanating from a 10-kilometer impact crater that occurs within the wall of a larger, 60-kilometer-wide crater. In the central part is a lobe-shaped portion of the ejecta blanket from the smaller crater. The crater is elliptical not because of an angled (oblique) impact, but because it occurred on the steep slopes of the wall of a larger crater. This caused it to be truncated along the slope and elongated perpendicular to the slope. As a result, any impact melt from the smaller crater would have preferentially deposited down slope and towards the floor of the larger crater (towards the west).

Within this deposit, we can see fine-scale morphological features in the form of a dense network of small ridges and pits. These crater-related pitted materials are consistent with volatile-rich impact melt-bearing deposits seen in some of the best-preserved craters on Mars (e.g., Zumba, Zunil, etc.). These deposits formed immediately after the impact event, and their discernible presence relate to the preservation state of the crater. This image is an attempt to visualize the complex formation and emplacement history of these enigmatic deposits formed by this elliptical crater and to understand its degradation history.



Written by: Arya Bina, Elise Harrington, Eric Pilles and Livio Tornabene (audio: Tre Gibbs)  (12 January 2017)
 
Acquisition date
02 October 2016

Local Mars time
15:15

Latitude (centered)
-18.605°

Longitude (East)
68.925°

Spacecraft altitude
258.8 km (160.9 miles)

Original image scale range
25.9 cm/pixel (with 1 x 1 binning) so objects ~78 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection
Equirectangular

Emission angle
0.2°

Phase angle
45.8°

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

Solar longitude
233.7°, Northern Autumn

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  355.1°
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   (682MB)

IRB color
map-projected   (412MB)

JP2 EXTRAS
Black and white
map-projected  (340MB)
non-map           (387MB)

IRB color
map projected  (139MB)
non-map           (365MB)

Merged IRB
map projected  (167MB)

Merged RGB
map-projected  (161MB)

RGB color
non map           (358MB)
BONUS
4K (TIFF)
8K (TIFF)

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-Caltech/UArizona

POSTSCRIPT
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.