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 image of a cone with varying textures 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 melting from multiple impact strikes.

Edited Mars Reconnaissance Orbiter image of a pit on Mars. Cropped, processing variant that lets you see the bottom.

Edited Mars Reconnaissance Orbiter image of chaotic terrain in Eos Chasma. Color variant.

Edited Mars Reconnaissance Orbiter image of sand dunes in a crater north of Antoniadi Crater.

Edited Mars Reconnaissance Orbiter image of fans of material in Roddy Crater.

Edited Mars Reconnaissance Orbiter image of deltas on Mars, looking for clinoforms (some type of geologic feature).

Edited Mars Reconnaissance Orbiter image of southern Isidis Planitia.

Edited Mars Reconnaissance Orbiter image of a pit near the Elysium Mons volcano. Processing variant.

Edited Mars Reconnaissance Orbiter image of frost and patterns on Mars. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of the Gigas Sulci region of Mars.

Edited Mars Reconnaissance Orbiter image of ridges in the Hellas Planitia region of Mars. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of geodiversity in Mawrth Vallis on Mars. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of colorful landforms in Mawrth Vallis on Mars.

Edited Mars Reconnaissance Orbiter image of convoluted folds in deposits on the floor of Ius Chasma.

Edited Mars Reconnaissance Orbiter image of gullies and exposed colors.

Edited Mars Reconnaissance Orbiter image of teardrop defrosting on sand dunes on Mars. Red channel.

Edited Mars Reconnaissance Orbiter image of an abrupt cliff next to a canyon in Aureum Chaos.

Edited Mars Reconnaissance Orbiter image of sand dunes in Hyperborei Cavi. (I love Martian names.) Color/processing variant.

Edited Mars Reconnaissance Orbiter image of secondary impact craters and their shapes on Mars.

Edited Mars Reconnaissance Orbiter PR image of a scoured section of the floor of Eos Chasma. Color/processing variant.

Edited Mars Reconnaissance Orbiter image of sand dunes named Tleilax.

Edited Mars Reconnaissance Orbiter image of chaotic terrain in Eos Chasma.

Edited Mars Reconnaissance Orbiter image of flow ridges in brain terrain (what a wonderful name for a type of terrain!) in Claritas Fossae. Color variant.

Edited Mars Reconnaissance Orbiter image of sandstone in west Candor Chasma on Mars.

Edited Mars Reconnaissance Orbiter image of colorful bedrock in a crater on Mars' northern plains. Color/processing variant.