[Curiosities] Tantalizing Science and Dangerous Hazards: NASA’s Curiosity Mars Rover Reaches Long-Awaited Salty Region

[Mr.Hacker]

 

After trekking this summer through a narrow, sand-lined pass, NASA’s Curiosity Mars rover recently arrived in the “sulfate-bearing unit.” This long-sought region of Mount Sharp is enriched with abundant salty minerals.

Scientists hypothesize that the minerals were left behind billions of years ago when the water dried up in streams and ponds. Assuming this hypothesis is correct, these minerals offer tantalizing clues as to how – and why – the Red Planet’s climate changed from being more Earth-like to the frozen desert it is today.

Curiosity’s View of ‘Paraitepuy Pass’: NASA’s Curiosity Mars rover used its Mast Camera, or Mastcam, to capture this panorama while driving toward the center of this scene, an area that forms the narrow “Paraitepuy Pass” on Aug. 14, the 3,563rd Martian day, or sol, of the mission. Credits: NASA/JPL-Caltech/MSSS

Years before Curiosity landed in 2012, the minerals were spotted by NASA’s Mars Reconnaissance Orbiter, so scientists have been waiting a long time to see this terrain up close. Soon after arriving, the rover discovered a diverse array of rock types and signs of past water, among them popcorn-textured nodules and salty minerals such as magnesium sulfate (Epsom salt is one kind), calcium sulfate (including gypsum), and sodium chloride (ordinary table salt).They selected a rock nicknamed “Canaima” for the mission’s 36th drill sample, and choosing was no easy task. Along with scientific considerations, the team had to factor in the rover hardware. Curiosity uses a percussive, or jackhammering, rotary drill at the end of its 7-foot (2-meter) arm to pulverize rock samples for analysis. Worn brakes on the arm recently led the team to conclude that some harder rocks may require too much hammering to drill safely.

“As we do before every drill, we brushed away the dust and then poked the top surface of Canaima with the drill. The lack of scratch marks or indentations was an indication that it may prove difficult to drill,” said Curiosity’s new project manager, Kathya Zamora-Garcia of NASA’s Jet Propulsion Laboratory in Southern California. “We paused to consider whether that posed any risk to our arm. With the new drilling algorithm, created to minimize the use of percussion, we felt comfortable collecting a sample of Canaima. As it turned out, no percussion was needed.”

The mission’s scientists look forward to analyzing portions of the sample with the Chemical and Mineralogy instrument (CheMin) and the Sample Analysis at Mars instrument (SAM).

Difficult Driving
The journey to the sulfate-rich region took Curiosity through treacherous terrain, including, this past August, the sandy “Paraitepuy Pass,” which snakes between high hills. It took the rover more than a month to safely navigate in order to finally reach its destination.

While sharp rocks can damage Curiosity’s wheels (which have plenty of life left in them), sand can be just as hazardous, potentially causing the rover to get stuck if the wheels lose traction. Rover drivers need to carefully navigate these areas.