Subliming Ice
Subliming Ice
ESP_060698_2220  Science Theme: Glacial/Periglacial Processes
This enhanced-color image shows a 45-meter-diameter crater that formed sometime between October 2010 and May 2012 in so-called “brain” terrain on Mars. HiRISE has been monitoring this crater to look for changes in the bright icy material exposed in the crater wall and some of the ejecta blocks.

This material is interpreted as water ice because its extent changes with time, consistent with slow sublimation caused by solar heating. (Sublimation is the process when a solid converts directly into a gaseous state.) By comparing this image with another one (ESP_046707_2220) taken in July 2016, we see that some of the ejecta blocks have vanished since then. It appears that fresh ice has been exposed on the east wall of the crater since 2016, perhaps due to slumping of dirty material. When we apply different color enhancements to these two images, we see that the color of the scene did not actually change much.

Written by: Ken Herkenhoff (audio: Tre Gibbs)  (16 September 2019)
Acquisition date
09 July 2019

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
296.9 km (184.5 miles)

Original image scale range
from 29.7 cm/pixel (with 1 x 1 binning) to 59.5 cm/pixel (with 2 x 2 binning)

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
41°, with the Sun about 49° above the horizon

Solar longitude
50.1°, Northern Spring

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  344.9°
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   (304MB)

IRB color
map-projected   (199MB)

Black and white
map-projected  (152MB)
non-map           (109MB)

IRB color
map projected  (46MB)
non-map           (160MB)

Merged IRB
map projected  (94MB)

Merged RGB
map-projected  (91MB)

RGB color
non map           (142MB)
10K (TIFF)

HiClip mini HD

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

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.