jeudi 28 septembre 2017

Textures in Deuteronilus Mensae & Go with the (Bright) Flow












NASA - Mars Reconnaissance Orbiter (MRO) logo.

Sept. 28, 2017

Textures in Deuteronilus Mensae

This enhanced color image from NASA's Mars Reconnaissance Orbiter shows the surface of a lobate debris apron in the Deuteronilus Mensae region of Mars, on the boundary between the Northern plains and Southern lowlands. These lobe-shaped formations commonly emanate from mesas in this region and have pitted, lineated textures that suggest the flow of water ice.

Results from the SHARAD (SHAllow RADar) instrument on MRO indicate that lobate debris aprons in Deuteronilus Mensae, similar to those visible here, are composed of material dominated by ice and are interpreted to be potential debris-covered glaciers or rock glaciers.

These debris apron surfaces are also covered by an ice-rich deposit that weâ??ve observed draping over entire regions in the mid-latitudes of Mars. It is this mantling deposit that filled in the crater, with its subsequent removal around the outer margins, probably due to differential sublimation of the ice. The same textures in the center of the crater are like those of the surrounding terrain.

Go with the (Bright) Flow

NASA's Mars Reconnaissance Orbiter observes many slopes in the middle latitudes of Mars showing icy flows or glaciers. The region shown here, in the south-facing slope of a crater, is unusual because the flows have bright highlights.

The color and brightness variations are likely due to surface coatings of bright dust and dark sand. There is no evidence that these flows are currently active, but they may have been active only millions of years ago. These flows may well contain ice today in their interiors, as confirmed in places by the subsurface radar experiment on MRO.

This is a stereo pair with https://www.uahirise.org/ESP_014058_1450

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.

NASA's Mars Reconnaissance Orbiter (MRO): http://www.nasa.gov/mission_pages/MRO/main/index.html

Images, Text, Credits: NASA/Tony Greicius/JPL-Caltech/Univ. of Arizona.

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