NASA's Curiosity Mars Rover carries a fistful of dark sand from a linear dune from the Red Planet in order to analyse it. It's the first analysis of the active Martian dunes that's taking place. Four sites have been observed by the rover previously from early February to early April, which are compared to the findings that took place in late 2015 and early 2016 during its exploration of crescent-shaped dunes.
One of the questions that this Martian dune campaign is detecting is, how exactly the winds shaped the dunes which are located so closely. Another question that the researchers are looking for is, whether the sand grains are sorted by the Martian winds which impact the distribution of the mineral compositions, this would have impact on the analysis of the Martian sandstones.
"At these linear dunes, the wind regime is more complicated than at the crescent dunes we studied earlier," said Mathieu Lapotre of Caltech, in Pasadena, California, who helped lead the Curiosity science team's planning for the dune campaign, a NASA statement revealed.
"There seems to be more contribution from the wind coming down the slope of the mountain here compared with the crescent dunes farther north," Lapotre said further.
As per the findings, the linear dunes are located at the south at a distance of around 1.6 kilometers (approx one mile) from the crescent of the dunes.
The dunes being analysed in both the studies belong to the part of a dark-sand swath known as the Bagnold Dunes which is spread over a span of several miles. The northwestern edge of Mount Sharp, which the Curiosity Rover is climbing, is bordered by the dune field.
"There was another key difference between the first and second phases of our dune campaign, besides the shape of the dunes," Lapotre said.
"We were at the crescent dunes during the low-wind season of the Martian year and at the linear dunes during the high-wind season. We got to see a lot more movement of grains and ripples at the linear dunes," he added.
In order to investigate the direction and strength of the wind, the rover team is utilising the change-detection pairs of images taken at different times in order to figure out the movement of the sand grains.
These winds make it hard for the arm of the rover to insert the sand samples accumulated by it into its instruments, as per a report by The Register.
Though the Curiosity's Rover Environmental Monitoring Station (REMS) transmits the information related to the Mars such as the data related to weather, temperature, pressure and humidity daily, the instrument doesn't have its wind-sensing ability anymore. When the rover landed on Mars in 2012, it was found that two of its six rovers were defective. The wind information was provided by the remaining sensors through the prime mission of the rover, as well as the first two-year extended mission.
A sand sample dug out by the rover from the linear dune is presently in the sample-handling of the device present at the rover's arm. A part of it has been examined in the rover's Sample Analysis at Mars (SAM) instrument which is present inside it. The research team aims at sending the extra sample portions of the sand to the rover's Chemistry and Mineralogy (CheMin) instrument as well.
"A balky brake appears to be affecting drill feed mechanism performance," said Curiosity Deputy Project Manager Steven Lee, of NASA's Jet Propulsion Laboratory, Pasadena, California.
"In some cases, vibration has been observed to change feed effectiveness, so we're proceeding cautiously until we better understand the behavior. In the meantime, the engineering team is developing several methods to improve feed reliability," Lee added.
One factor in choosing to drive farther uphill before finishing analysis of the scooped sand is the status of Curiosity's rock-sampling drill, which has not been used on a rock since a problem with the drill feed mechanism appeared five months ago. Engineers are assessing how the use of vibration to deliver samples may affect the drill feed mechanism, which is used to move the drill bit forward and backwards. In addition, high winds at the linear-dunes location were complicating the process of pouring sample material into the entry ports for the laboratory instruments, the NASA statement revealed.