NASA's Mars rover Curiosity acquired this image using its Mars Hand Lens Imager (MAHLI) on Sol 809 Credit: NASA/JPL-Caltech/MSSS
As Curiosity continues to mend, I've been looking forward to our next drill sample of gray rock. Some interesting features we've seen on Vera Rubin Ridge are small "swallowtail crystals" often associated with the boundary between gray and red rocks on the ridge top. In thinking about these features, I wanted to take the opportunity to reflect on past results from when Curiosity was just beginning to explore Mt. Sharp at the Pahrump Hills region. Readers of this blog may remember that back on sol 809, after we brushed away the dust on target "Mojave," the team was surprised and excited to discover hundreds of millimeter-sized, rice-shaped crystals on its face. These crystals are geologic clues to what happened in the past. What were these unique features made of? How and when did they form?
Swallowtail Crystals Close to Drill Attempt at Inverness
This image was taken by ChemCam: Remote Micro-Imager (CHEMCAM_RMI) onboard NASA's Mars rover Curiosity on Sol 2163 (2018-09-06 12:10:38 UTC). Image Credit: NASA/JPL-Caltech/LANL
Curiosity scientist Linda Kah and colleagues address these questions in a new paper available in the journal Terra Nova titled "Syndepositional precipitation of calcium sulfate in Gale Crater, Mars." For this study, Kah and colleagues carefully studied the sizes, shapes, and orientations of the unusual crystals at Mojave and several nearby targets. They integrated these findings with the geologic setting, chemistry, and mineralogy of the Pahrump Hills area to infer the presence of shallow, salty, and sometimes ephemeral waters during this period in Gale's history.
Kah and co-authors explain that the crystal shapes are distinctive of gypsum salts that precipitate in lake, playa, and near-shore ocean environments. Interestingly, Curiosity did not detect any large differences in the composition of rocks containing crystals versus nearby, non-crystal-containing rocks. This result suggests the calcium sulfate that originally formed the crystals had either been dissolved at a later time and/or that the crystals had incorporated a lot of the original rocks around within them when they formed.
The shapes, sizes, and orientation of crystals give clues to how they grow. Kah and authors showed the crystals at Pahrump were randomly oriented and occurred between and within cemented layers. Combined with the crystals' elongated shapes, this suggests that they grew at the interface between loose, water-logged sediment and either shallow water or air. Interestingly, small amounts of organic (carbon-bearing) material can cause crystals to have shapes similar to those observed at Mojave, which is consistent with Curiosity findings of organic material in the Mojave drill sample.
The swallowtail crystals on Vera Rubin Ridge are also known shapes of gypsum crystals. Why are these crystals so different in form from what we saw back at Mojave? What does this all tell us about ancient environments at Gale Crater?
These blog updates are provided by self-selected Mars Science Laboratory mission team members who love to share what Curiosity is doing with the public.
Dates of planned rover activities described in these reports are subject to change due to a variety of factors related to the Martian environment, communication relays and rover status.
Contributors
Sterling Algermissen
Mission Operations Engineer; NASA/JPL; Pasadena, CA
Atmospheric Scientist; Texas A&M University; College Station, TX
Kristen Bennett
Planetary Geologist; USGS; Flagstaff, AZ
Fred Calef
Planetary Geologist; NASA/JPL; Pasadena, CA
Brittney Cooper
Atmospheric Scientist; York University; Toronto, Ontario, Canada
Sean Czarnecki
Planetary Geologist; Arizona State University; Tempe, AZ
Lauren Edgar
Planetary Geologist; USGS; Flagstaff, AZ
Christopher Edwards
Planetary Geologist; Northern Arizona University; Flagstaff, AZ
Abigail Fraeman
Planetary Geologist; NASA/JPL; Pasadena, CA
Scott Guzewich
Atmospheric Scientist; NASA/GSFC; Greenbelt, MD
Samantha Gwizd
Planetary Geologist; University of Tennessee; Knoxville, TN
Ken Herkenhoff
Planetary Geologist; USGS; Flagstaff, AZ
Rachel Kronyak
Planetary Geologist; University of Tennessee; Knoxville, TN
Sarah Lamm
Planetary Geologist; LANL; Los Alamos, NM
Michelle Minitti
Planetary Geologist; Framework; Silver Spring, MD
Claire Newman
Atmospheric Scientist, Aeolis Research; Pasadena, CA
Catherine O’Connell
Planetary Geologist; University of New Brunswick; Fredericton, New Brunswick, Canada
Melissa Rice
Planetary Geologist; Western Washington University; Bellingham, WA
Mark Salvatore
Planetary Geologist; University of Michigan; Dearborn, MI
Susanne Schwenzer
Planetary Geologist; The Open University; Milton Keynes, U.K.
Ashley Stroupe
Mission Operations Engineer; NASA/JPL; Pasadena, CA
Dawn Sumner
Planetary Geologist; University of California Davis; Davis, CA
Vivian Sun
Planetary Geologist; NASA/JPL; Pasadena, CA
Lucy Thompson
Planetary Geologist; University of New Brunswick; Fredericton, New Brunswick, Canada
Ashwin Vasavada
MSL Project Scientist; NASA/JPL; Pasadena, CA
Roger Wiens
Geochemist; LANL; Los Alamos, NM
Tools on the Curiosity Rover
The Curiosity rover has tools to study clues about past and present environmental conditions on Mars, including whether conditions have ever been favorable for microbial life. The rover carries:
The 3-sol weekend plan starts with targeted remote science (ChemCam and Mastcam observations), then completion of the thorough wheel imaging campaign .
The Sol 488 plan includes ChemCam and Mastcam observations of the Cumberland drill sample that was dumped in front of the rover, completing the campaign on the dump pile.
I'm on my way home from the ChemCam team meeting, so again not involved in MSL tactical operations, but saw that the Sol 487 plan includes dumping the last of the Cumberland drill sample and MAHLI imaging of the dump pile.
I'm uplink lead for the Opportunity Microscopic Imager and engineering cameras (Hazcams and Navcams) today, so have not been able to follow MSL planning as closely as usual.
The drive planned for last weekend went well, so another drive is planned for Sol 472, along with targeted remote science and MAHLI imaging of the rover wheels.
MSL launched from Florida two years ago today--I was pretty nervous that day, but the mission has obviously gone extremely well! Planning is restricted this week (results of the drive planned for Sol 465 will not arrive until tonight), so we are planning
MSL science planning has resumed! Today we are planning 3 sols, with the focus on dropping more of the drill sample into 4 of SAM's cups, for future analysis.
I was scheduled as MAHLI/MARDI uplink lead today, but there was nothing to do because all science planning is on hold while the power issue is being investigated.
Planning started at 6:30 this morning to allow enough time to plan 3 sols before we have to send the command sequences to the rover by 19:00 this evening.
MSL planning is still restricted, so we won't get confirmation of the drive planned for Sol 431 in time for planning Sol 432, which is therefore an untargeted-remote-sensing sol.
The autonomous navigation software could not find a safe path toward the rover's goal on Sol 404, so ended up in a configuration that prevented uplink of the Sol 405 command sequences directly to the high-gain antenna from Earth.
The short drive to the next contact science location at Waypoint 1 was successful, so we planned a lot of MAHLI images and a couple ChemCam observations of the veins in front of the rover .
The MSL team is celebrating the first Earth year of operations on the surface of Mars, at JPL, on NASA TV , and at participating institutions around the world.
We were happy to see that the long drive planned for last weekend went well , but don't expect to drive so far every sol until more software capabilities are checked out and cleared for use.
MSL passed one kilometer total drive odometry during the Sol 335 drive! Hopefully the two kilometer mark will be passed much more quickly, as we are halfway through the nominal mission of one Mars year (669 sols).
We decided to spend a bit more time investigating the "Shaler" outcrop using the arm instruments and ChemCam before starting the long drive to Aeolis Mons or "Mt.
"Contact science," including APXS and MAHLI close-up observations of a couple of rocks at the "Shaler" outcrop, are being planned for Sols 322 and 323.
I'm not on shift in any tactical operations roles, but have been helping finish up important observations in the "Cumberland" area before we drive away next week.
I'm not scheduled in any tactical operations roles this week, but havebeen calling into planning meetings for both MSL (Curiosity) and MER(Opportunity).
At long last, the MSL team has resumed planning science observations!I was MAHLI/MARDI uplink lead on Monday, and although we didn't planany activities with those cameras, it was good to be involved intactical operations again.
I'm scheduled as MAHLI/MARDI uplink lead again today, but there's nothing for me to do because the engineers at JPL are still working torecover from recent software anomalies.
I'm scheduled to serve as SOWG Chair today and tomorrow, but we won't be able to plan any new science observations because the recovery from the Sol 200 anomaly is not yet complete.
After taking a break from tactical operations for an MSL science team meeting (and a bit of vacation) last week, I'm back on as SOWG chair for Sol 195 planning.
Planning is still "restricted," so we had an opportunity to acquire more ChemCam and imaging data on Sol 181 while waiting for confirmation that the Sol 180 "mini-drill" test completed successfully.
Because the "drill-on-rock checkout" activity did not complete successfully on Sol 174, the MSL team had to work extra hard to determine how best to recover from the anomaly.
As SOWG Chair again, I worked hard today to fit as many observations into the Sol 175 plan as possible while leaving enough energy in the batteries for Sol 176 activities.
We have arrived at John Klein , the location selected for the first use of the drill! There are multiple potential drill targets in front of the rover, which must be flat as well as scientifically interesting .
I was MAHLI/MARDI uplink lead again for Sol 153 planning, but there were no MAHLI or MARDI observations in the plan, so I focused instead on advance planning for Sol 154.
A short "bump" toward slightly younger rocks in front of the rover was planned for Sol 151, and no MAHLI observations were included so I had an easy day as PUL.
RSS Feed
