Curiosity rover selfie on Mars
This selfie of NASA’s Curiosity Mars rover shows the vehicle at a drilled sample site called “Okoruso,” on the Naukluft Plateau of lower Mount Sharp. The scene combines several images taken with the rover’s Mars Hand Lens Imager on May 11.

NASA says one of the Curiosity rover’s future tasks could be to check out sites on Mars that may harbor trickles of salty water.

It’s been nearly four years since Curiosity was dropped into Gale Crater by a rocket-powered crane. Since that touchdown, the six-wheeled, 1-ton robot has found ample evidence that water once flowed through the territory it has explored.

Curiosity is now making its way up the side of Mount Sharp (a.k.a. Aeolis Mons), a 3-mile-high mountain in the middle of Gale Crater – and it’s making further discoveries along the way.

For example, scientists say they’ve identified an unusual mineral in a ground-up sample of rock that Curiosity analyzed. The mineral, known as tridymite, is typically associated with an explosive process known as silicic volcanism. That process has been seen at work on Earth in volcanoes such as Mount St. Helens, but it’s not thought to occur on Mars.

“The discovery of tridymite was completely unexpected,” NASA planetary scientist Richard Morris, the lead author of a study published in the Proceedings of the National Academy of Sciences, said in a news release. Morris and his colleagues are now trying to figure out whether a different kind of low-temperature process could create tridymite.

Meanwhile, other scientists are tracking seasonal changes in dark streaks on Martian slopes that are known as recurring slope lineae, or RSLs.

RSLs may be trickles of salty water that spread out during Mars’ spring thaw, and then shrink away. Or they could be a phenomenon that’s unrelated to water, such as dry avalanches.

NASA says two RSL candidates may be within Curiosity’s reach. The rover could use one of its ChemCam scientific instruments, known as the Remote Micro-Imager, to make spectral observations of those RSLs over time. Such observations could determine whether the streaks are actually caused by water, or whether something else is going on.

Right now, the dark streaks are considered “special regions” – places where extra precautions have to be taken to prevent contamination. That could limit how close Curiosity will be allowed to get.

“Kilometers away – it’s unlikely that it would be an issue,” Catharine Conley, NASA’s planetary protection officer, said in a news release issued today. “In terms of coming much closer, we need to understand well in advance the potential for Earth organisms to come off the rover, and that will tell us how far away the rover should stay.”

NASA says managers are currently considering a mission extension for Curiosity, and the scouting expedition would be part of that extended mission if it’s approved. A decision is expected within the next several months.

Like what you're reading? Subscribe to GeekWire's free newsletters to catch every headline

Job Listings on GeekWork

Find more jobs on GeekWork. Employers, post a job here.