Edited Mars Reconnaissance Orbiter image of a circular feature (not necessarily a crater) in the residual ice cap of the South Pole of Mars. PR version. Processing variant.

Edited Mars Reconnaissance Orbiter image of seasonal monitoring of sand dunes in Mclaughlin Crater.

Edited Mars Reconnaissance Orbiter image of bedrock in Meridiani Planum.

Edited Mars Reconnaissance Orbiter image of layered terrain and slopes.

Edited Mars Reconnaissance Orbiter image of fingerprint terrain on Mars. Processing variant.

Edited Mars Reconnaissance Orbiter image of a crater whose slopes are being monitored for changes. Color variant.

Edited Mars Reconnaissance Orbiter image of ridges and a mount in Aurorae Chaos. Color variant.

Edited Mars Reconnaissance Orbiter image of gullies in a crater on Mars.

Edited Mars Reconnaissance Orbiter image of dust devil tracks on Mars.

Edited Mars Reconnaissance Orbiter image of hills ("knobs") and valleys in the Acidalia Planitia region of Mars.

Edited Mars Reconnaissance Orbiter image of layering in a crater west of the Arabia Terra region of Mars. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of valleys north of Huygens Crater.

Edited Mars Reconnaissance Orbiter image of a kieserite deposit in Hebes Mensa.

Edited Mars Reconnaissance Orbiter image of layered deposits (perhaps indicating an ancient lake) in Uzboi Vallis. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of an unexpected slumping (seen as a streak on the side of the crater) in Melas Chasma.

Edited Mars Reconnaissance Orbiter image of layering in a crater west of the Arabia Terra region of Mars. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of dust devil tracks on Mars.

Edited Mars Reconnaissance Orbiter image of sand dunes in Abalos Undae.

Edited Mars Reconnaissance Orbiter image looking for frost on the rim of Corozal Crater - it's thought that frost may play a roll in the creation of gullies. Processing variant.

Edited Mars Reconnaissance Orbiter image of rugged-looking terrain in Terra Cimmeria.

Edited Mars Reconnaissance Orbiter image of melting from multiple impact strikes. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of terrain south of the Argyre Region on Mars.

Edited Mars Reconnaissance Orbiter image of a plateau on Mars. Processing variant.

Edited Mars Reconnaissance Orbiter image of sand on the floor of Pasteur Crater. Color variant.

Edited Mars Reconnaissance Orbiter image of moraine-like features on mounds in Hellas Montes.

Edited Mars Reconnaissance Orbiter image of a scene on Mars.

Edited Mars Reconnaissance Orbiter Image of possible light-toned clays on the basin floor of Ladon Valles.

Edited Mars Reconnaissance Orbiter image of an impact crater on Mars north of Valles Marineris.

Edited Mars Reconnaissance Orbiter image of Victoria Crater, where Opportunity spent a year or so.

Edited Mars Reconnaissance Orbiter image of a (large) trough in Coprates Catena.

Edited Mars Reconnaissance Orbiter image of a ridge network in Hellas Planitia on Mars. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of really rugged-looking terrain on Mars.

Edited Mars Reconnaissance Orbiter PR image of sand dunes in the center of Juventae Chasma. Color/processing variant.

Original caption: The ultimate origin of the sediment that forms Martian dunes has long been debated. While sand dunes on Earth are primarily sourced by quartz-bearing components of granitic continental crust, it's often suggested that sand on Mars derives from eroded volcanic flows or sedimentary deposits, but exact sources are often vague.

This image reveals a unique situation where this small dune field occurs along the summit of the large 1-mile-tall mound near the center of Juventae Chasma. The layered mound slopes are far too steep for dunes to climb, and bedform sand is unlikely to come from purely airborne material. Instead, the mound's summit displays several dark-toned, mantled deposits that are adjacent to the dunes and appear to be eroding into fans of sandy material.

Along with local HiRISE images, spectral data from other instruments on MRO have confirmed such units are likely to be the sand source for these mound summit dunes and reveal how landscape evolution on Mars might occur.

The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. [The original image scale is 27.8 centimeters (10.9 inches) per pixel (with 1 x 1 binning); objects on the order of 83 centimeters (32.7 inches) across are resolved.] North is up.

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. 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.

Image Credit:

NASA/JPL-Caltech/Univ. of Arizona

Image Addition Date:

2018-10-01

Edited Mars Reconnaissance Orbiter image of a ridge network in Hellas Planitia on Mars.

Edited Mars Reconnaissance Orbiter image of what looks like a fracture on the surface of Mars.

Edited Mars Reconnaissance Orbiter Image of an "atypical" landform amongst sand dunes in a north polar erg.

Edited Mars Reconnaissance Orbiter context image of erosion in Cerberus Fossae. Processing variant.

Edited Mars Reconnaissance Orbiter image of a crater (or huge pit) with a dune field at the bottom.

Slope streaks, commonly seen in dust-rich equatorial regions of Mars, have been observed in all spacecraft images from the early Mariner missions to the most recent Mars Reconnaissance Orbiter (MRO) mission.

Edited Mars Reconnaissance Orbiter image of the edge of a steep and fractured scarp on Mars where frost avalanches occur. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of frost and patterns on Mars.

Edited Mars Reconnaissance Orbiter image of part of Ius Chasma on Mars.

Edited Mars Reconnaissance Orbiter image of layers or rock peeking out from sand dunes in Danielson Crater on Mars. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of sand dunes named Kolhar. Color variant.

Edited Mars Reconnaissance Orbiter image of a long scarp on Mars. Processing varint.

Edited Mars Reconnaissance Orbiter image of Arom Chaos landforms. (I'm not too sure about "Arom" Chaos - I'm wondering if I made a typo...)

Edited Mars Reconnaissance Orbiter image of layers or rock peeking out from sand dunes in Danielson Crater on Mars. Inverted grayscale variant.

Edited Mars Reconnaissance Orbiter image of a pit in Ulysses Fossae.

Edited Mars Reconnaissance Orbiter image of Mawrth Vallis, and the strange mottled landscape. Processing variant.

Edited Mars Reconnaissance Orbiter image of sand dunes with furrows. Color variant.