It Shrinks! It Cracks!
It Shrinks! It Cracks!
ESP_049723_1880  Science Theme: Volcanic Processes
Given enough time, impact craters on Mars tend to fill up with different materials. For instance, some craters on Mars had lakes inside them in the past. When these lakes dried out, they left behind traces of their past existence, such as sedimentary deposits (materials that were carried along with the running water into the lake inside the crater and then settled down). Some craters, especially in high latitudes, contain ice deposits that filled the crater when an earlier ice age allowed ice to extend into the crater’s latitude.

Here, we have a crater that lies close to Elysium, a major volcanic system on Mars. The whole region surrounding the crater was at some point covered by lava from the volcano creating vast lava plains, and in the process, flooding impact craters in their way.

When the lava eventually cooled down, it solidified and began to shrink in size. This shrinking led to formation of cracks on the surface of the lava that grew in a circular pattern matching the shape of the crater it was filling.

Scientists can study these fractures and estimate how much it shrank in volume to better understand the properties of the lava (such as its temperature) during the time it filled the crater.

Written by: M. Ramy El-Maarry (audio: Tre Gibbs)  (20 April 2017)
Acquisition date
05 March 2017

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
276.1 km (171.6 miles)

Original image scale range
55.3 cm/pixel (with 2 x 2 binning) so objects ~166 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
37°, with the Sun about 53° above the horizon

Solar longitude
328.2°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  331.6°
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IRB color
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Black and white
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non-map           (155MB)

IRB color
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non-map           (140MB)

Merged IRB
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Black & white is 5 km across; enhanced color about 1 km
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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.