While some of us might only be dreaming of sticking our toes in the sand right about now, the Curiosity rover is actually doing so. But it’s no vacation for the rover, as she makes her way through some very unusual and striking sand dunes on Mars. The Bagnold Dune Field lies along the northwestern flank of Mt. Sharp — Curiosity’s main target for its mission — and this is the first time ever we’ve had the opportunity to do close-up studies of active sand dunes anywhere besides Earth.
Thanks to Andrew Bodrov for sharing his compilation of this 57-image mosaic ‘selfie,’ and you can play around with an interactive version below to see some great views of the dunes. The images were taken by the rover’s Mars Hand Lens Imager (MAHLI) on Sol 1228 (January 19, 2016).
Sampling the Dunes with SAM
While the rover stopped to take these images to create this 57-image mosaic ‘selfie,’ Curiosity has also been quite busy, both navigating through the dunes and stopping to do some sampling. Excitingly, the rover scooped up some of the sand and sent it to the on-board chemistry lab, the Sample Analysis at Mars (SAM). This is only the second time the scoop has been used to deliver small portions – usually about the size of a half of a baby aspirin –to be analyzed; the rover’s drill has been used several times to get samples.
Curiosity scooped its first dune sample on Jan. 14, but the rover stuck in its wheel briefly, scuffing it with a wheel. “The scuff helped give us confidence we have enough sand where we’re scooping that the path of the scoop won’t hit the ground under the sand,” said Michael McHenry, who is the rover planner for collecting these samples.
I had the chance to visit with John Michael Morookian, the rover planning team lead for Curiosity at JPL about two weeks ago, and he said the plan was to drive into the dune a short distance, get samples with the scoop and deliver them to the experiments on board.
Morookian explained that from orbital images from the HiRISE camera on the Mars Reconnaissance Orbiter, the team knows there is a good path among the dunes for the rover to navigate, and there should be no danger of the rover getting stuck or trapped.
“We’ll be circumnavigating them, there is plenty of path available,” he said. “This is not impassible area. The rover will be at this particular site doing the sampling for approximately the month of January, and the current plan is to take a long path about a kilometer circumnavigating the dunes to get to less active dunes that are part of the same field of dunes.”
Getting the samples from the scoop to SAM involves a set of complex moves of a multi-chambered device on the rover’s arm passing the material through a sieve that screened out particles bigger than 150 microns (0.006 inch); some of the material that passed the sieve was dropped into laboratory inlet ports from a “portioner” on the device.
“We start the vibration and gradually tilt the scoop,” Morookian explained. “The material flows off the end of the scoop, in more of a stream than all at once.”
The material blocked by the sieve is dumped onto the ground.
According to Ryan Anderson from the Curiosity team, the rover Mastcam and MAHLI cameras are both thoroughly documenting the scooping process, and the Mastcam also is doing observations of the dump piles left over from the scooping, and the ChemCam will take passive spectra of the piles. The Mastcam will also be imaging a dune names “Hebron” several times to observe any changes in the dune while the rover is nearby.
And if you’re wondering why the rover’s arm doesn’t show up on the self image mosaics, read our previous article which explains it here.