On the west (left) side of this image from NASA's Mars Reconnaissance Orbiter, fairly textbook-looking barchan sand dunes sit atop the bedrock. Barchan dunes pointing in the opposite direction are just a few kilometers away to the east. In between these opposing barchan dunes are star dunes. Barchan dunes form when the sand-moving wind is fairly unidirectional. Star dunes, in contrast, form when the sand-moving wind comes from multiple directions -- not all at once, but from varying directions at different times of day or year. Where is the sand coming from? As with most places on Mars...well, that's an area of on-going research. But the star dunes are telling us that this area seems to be accumulating sand. https://photojournal.jpl.nasa.gov/catalog/PIA21934

Dunes and more Dunes

Dunes

Dune

Dunes

Textures Where Curiosity Rover Studied a Martian Dune

This view from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover shows two scales of ripples, plus other textures, in an area where the mission examined a linear-shaped dune in the Bagnold dune field on lower Mount Sharp. The scene is an excerpt from a 360-degree panorama acquired on March 24 and March 25, 2017, (PST) during the 1,647th Martian day, or sol, of Curiosity's work on Mars, at a location called "Ogunquit Beach." Crests of the longer ripples visible in the dark sand of the dune are several feet (a few meters) apart. This medium-scale feature in active sand dunes on Mars was one of Curiosity's findings at the crescent-shaped dunes that the rover examined in late 2015 and early 2016. Ripples that scale are not seen on Earth's sand dunes. Overlaid on those ripples are much smaller ripples, with crests about ten times closer together. Textures of the local bedrock in the foreground -- part of the Murray formation that originated as lakebed sediments -- and of gravel-covered ground (at right) are also visible. The image has been white-balanced so that the colors of the colors of the rock and sand materials resemble how they would appear under daytime lighting conditions on Earth. https://photojournal.jpl.nasa.gov/catalog/PIA11242

Dune Restoration - October 2018

Restoration efforts are underway to the dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. One the dune is built up, native coastal vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Dune Restoration - October 2018

Restoration efforts are underway to the dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. One the dune is built up, native coastal vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Dune Restoration - October 2018

Restoration efforts are underway to the dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. One the dune is built up, native coastal vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Dune Restoration - October 2018

Restoration efforts are underway to the dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. One the dune is built up, native coastal vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Dune Restoration - October 2018

Restoration efforts are underway to the dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. One the dune is built up, native coastal vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Dune Restoration - October 2018

Native vegetation is being planted in a portion of the restored dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. Once the dune is built up, native vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Dune Restoration - October 2018

Restoration efforts are underway to the dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. One the dune is built up, native coastal vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Dune Restoration - October 2018

Restoration efforts are underway to the dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. Once the dune is built up, native coastal vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Dune Restoration - October 2018

Restoration efforts are underway to the dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. Once the dune is built up, native coastal vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Dune Restoration - October 2018

Restoration efforts are underway to the dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. Once the dune is built up, native coastal vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Rabe Dunes in IR

This image of Rabe Crater and the region around it was collected using the IR (infrared) camera. The brighter the material, the warmer the surface is. Most dunes on Mars are dark in visible wavelengths and bright in infrared. The majority of large craters in the southern hemisphere contain dunes on the crater floor. Orbit Number: 67144 Latitude: -46.329 Longitude: 34.079 Instrument: IR Captured: 2017-02-01 12:57 http://photojournal.jpl.nasa.gov/catalog/PIA21519

Dune Restoration - October 2018

Native vegetation is being planted in a portion of the restored dunes at the north beaches at NASA’s Kennedy Space Center in Florida on Oct. 8, 2018. About 450,000 cubic yards of beach-quality sand, tested for compatibility, is being transported to the space center’s beaches. One the dune is built up, native coastal vegetation will be replanted, helping to stabilize the dune and offer a habitat for Kennedy’s coast wildlife. Dunes are affected by beach erosion and storm surge from tropical events, such as hurricanes. Restoration began in spring 2018 and is targeted to be completed by April 2019.

Dark Dunes Over-riding Bright Dunes

Martian Morse Code

These dark dunes are influenced by local topography. The shape and orientation of dunes can usually tell us about wind direction, but in this image, the dune-forms are very complex, so it's difficult to know the wind direction. However, a circular depression (probably an old and infilled impact crater) has limited the amount of sand available for dune formation and influenced local winds. As a result, the dunes here form distinct dots and dashes. The "dashes" are linear dunes formed by bi-directional winds, which are not traveling parallel to the dune. Instead, the combined effect of winds from two directions at right angles to the dunes, funnels material into a linear shape. The smaller "dots" (called "barchanoid dunes") occur where there is some interruption to the process forming those linear dunes. This process is not well understood at present and is one motivation for HiRISE to image this area. http://photojournal.jpl.nasa.gov/catalog/PIA20735