From February to April this year, NASA's Curiosity Mars rover probed into four sites near a linear dune on the Red Planet to compare the samples of dark sand taken here to those that was found in 2015 and 2016 when it investigated the crescent-shaped dunes.
Dark Sand From Mars's Linear Sand Dune
The newly taken samples from the linear sand dune, which is located uphill of Mount Sharp and about a mile south from the crescent dunes, will go through an onboard analysis that will complete a two-phase campaign.
The crescent and linear dunes are both parts of a dark-sand swath known as Bagnold Dunes, which lines the northwestern flank of Mount Sharp, where the Curiosity rover is currently climbing.
Objective Of The Dune Campaign In Mars
The dune campaign on the Red Planet aims to know how winds on the Red Planet shape dunes that are on the same side of a mountain and are relatively close together into varying patterns. It also aims to know if the winds sort the grains of sand in a manner that influences how mineral compositions are distributed, which would have an effect on studies of sandstone on Mars.
Linear Dunes And Crescent Dunes On Red Planet
Besides the shape of the dunes, researchers also noted other differences between the two phases of the campaign. The wind regime in the linear dunes, for instance, was found to be more complicated compared with the crescent dunes.
"There seems to be more contribution from the wind coming down the slope of the mountain here compared with the crescent dunes farther north," said Mathieu Lapotre of Caltech, who added that they have observed more grain and ripple movements at the linear dunes than at the crescent dunes.
Observations at the crescent dunes were made during the low-wind season and those at the linear dunes were made during the high-wind season.
The rover team now studies wind strength and direction using change-detection pairs of images that were captured at different times revealing the movement of the sand grains.
A sample of sand taken from the linear dune is in the probe's sample-handling device found at the end of its arm. A portion has already been analyzed by the rover's Sample Analysis at Mars or SAM instrument.
Researchers said that the type of wind-sculpted ripples on the Red Planet has not been seen on Earth and the link of the sand ripples to the thin Martian atmosphere seen today offers clues about the history of the planet's atmosphere.
"Earth and Mars both have big sand dunes and small sand ripples, but on Mars, there's something in between that we don't have on Earth," Lapotre said.
NASA's Aging Mars Probe
NASA's Curiosity rover has been exploring the Red Planet for about five years. Earlier this year, the U.S. space agency revealed that the probe has broken its wheel but said that the vehicle is still capable of reaching all destinations that were planned for its mission.
"For the past four years, rover drive planners have used enhanced methods of mapping potentially hazardous terrains to reduce the pace of damage from sharp, embedded rocks along the rover's route," NASA said in a statement.