NASA’s Mars Curiosity Rover has captured pictures of a linear sand dune on the Red Planet made of dark black soil. While collecting samples of the same dark sand on board the rover, these stunning pictures were captured by the rover. The rover has been observing four different sites located near these black Sand Dunes since early February to early April to compare the crescent-shaped sand dunes that were discovered in late 2015 and early 2016.

Mars’ active linear sand dunes

This Martian dune campaign is being undertaken to understand how these dunes - comparatively close to each other and located on the same side of the mountain - are shaped into different patterns by the wind.

Apart from these the NASA scientists are also trying to understand whether the wind sorts the sand grains, which may affect the distribution of mineral composition that may have an implication on the study of Martian sandstones.

Mathieu Lapotre from California University of Technology asserted that the “wind regime” was more complex at the Linear sand dunes vis-à-vis the crescent-shaped ones, which were examined by scientists previously.

He further added that there is more than one contribution of the wind that flows down from the slope of the mountain vis-à-vis wind flow up north, which is responsible for lending crescent shapes to the sand dunes. The linear active sand dunes that have been recently discovered is located about a mile south from the crescent dunes found in late 2015 and early 2016.

The dunes

Both the locations of the study – the linear- and crescent-shaped dunes - have a swath of black-colored sand dunes named Bagnold Dunes. These sand dunes are several miles long and line the north-western flank of Mountain Sharp. Curiosity rover is currently climbing this mountain when it pictured these linear black dunes.

Wind a major factor for the shape and other characteristics of the dunes?

Apart from the shape of the two dunes that has been discovered in the two phases of the initiative, another major difference that was spotted between the two dunes were the number of ripples and movement of grains on the dunes. It was observed that the linear ones located uphill had more ripples and movement of grains compared to the crescent ones found in the northern part of Mars.

The linear-shaped dunes – according to Lapotre – were discovered during the high-wind season of the Martian calendar. By comparison, the crescent ones were found during the low-wind season.

The rover team is now taking change-detection pairs of images at different points of time to check on grain movement and also assess the wind direction and strength. This methodology is being applied as the wind-sensing capability of Curiosity Rover’s Environmental Monitoring Station is no longer accessible.