Bright block in the image center is the next potential drill spot, "Broad Cairn."

After a short six meter drive to "Hallaig," the science team began the investigation of a new potential drill target named "Broad Cairn," a flat spot on a bright block in the clay-bearing unit. To confirm whether this location is high in potassium (K), the rover was commanded to clean off the spot with the dust removal tool (DRT), then take some close-up pictures with the MAHLI camera, followed by an APXS integration at the right time of day to maximize the data quality. Since getting the data back expeditiously was the highest priority, other science observations were pushed to the next planning sol. For now, the science team waits with bated breath for the results.

Curiosity is investigating an area that is very high in potassium, and we're trying to characterize the distribution and the source of that potassium. Yesterday we did a short drive to get one of these potassium-rich rocks into our workspace - "Grampian Mountains." While this target isn't viable for drilling, it is a good example of this potassium-rich area, which is now in our workspace (See image). We'll be starting out with some contact science (APXS and MAHLI) on the target. After the arm activities, there is a long targeted science block with ChemCam and Mastcam of several targets, including Grampian Mountains. "Annbank" and (to a lesser extent) "Brimmond" have similarities to the Woodland Bay block that was examined on sol 2359 (and which might be another possible drill target), so we're examining them to make a comparison. Our fourth target is "Balintore," which is part of our systematic bedrock survey; we're looking for more potassium-rich bedrock.

After finishing up the science observations at this location, Curiosity will be heading toward what we hope is our next drill location, target "Hallaig"; Hallaig rock was already identified by ChemCam as being potassium-rich. The rover planner evaluation looks promising for drilling, though it is still unclear from remote sensing how representative Hallaig is of this general area. The rover planners are able to turn and drive straight to this target; the terrain is benign enough that the parking requirements for drilling are not highly constraining. Our post-drive imaging will include high-quality color imaging of two spots on the rock to help us evaluate them for possible drilling. If things look good, we may be drilling as early as the weekend!

Image taken by the Mars Hand Lens Imager (MAHLI), on Sol 2409 at 09:18:51 UTC. It shows the target Dunoon. This image is about 45 mm by 34 mm.

Curiosity is continuing the investigations at "Rigg." The image in this update shows a close up taken by the MAHLI Hand Lens imager to allow the detailed investigation of the materials that make up the field of ripples. Things the team is looking for are grain size and grain size distribution, and the shape of the grains. In addition to that the colour and lustre of the different grain varieties are of interest to allow us to analyse the variation of phases in the sand. One feature to note, for example, are the pinkish grains on the surface, which appear to be larger than all others.

Tosol's plan is a three-sol plan with many activities imaging the sand ripples and investigating their chemistry. APXS will measure the targets "Nairn" and "Ellon," to investigate the differences of the different soil colours and grain sizes. ChemCam's plans include the soil targets "Seafield Tower," "Saltire" and "Selkirk," whereby Seafield Tower and Saltire are on ripple crests and Selkirk is on a ripple flank. There also is one rock target to investigate a rock colour variation at the target "Camustianavaig."

Mastcam will document all ChemCam targets, but also take two mosaic images, one of the workspace and one looking back at the "Aberlady" and "Kilmarie" drill target area. MAHLI will take a look at the APXS targets from the past and this plan, which are "Donoon," "Gairsay," "Ellon" and "Nairn." Also in the plan are ENV activities and DAN active and passive measurements.

Besides all the science, housekeeping activities are prominent in the plan, too. Curiosity will take images of the drill bit, and do a ChemCam calibration activity.

After spending the weekend playing in the sand of a nearby ripple field, Curiosity is back on the move, searching for our next drill target. Since nothing in our current workspace stuck out as an obvious drill candidate, we planned a ~10 meter drive south towards an area that may be more promising.

But there is still lots to get done here before we leave, including targeting "Galashiels" with APXS and more distant "Hallaig" with the ChemCam LIBS instrument in order to characterize the chemical composition of these rocks. Although unreachable from our current position, "Hallaig" is being considered for drilling pending the ChemCam results. Tosol's plan also included a Mastcam stereo mosaic of the southern side of the Vera Rubin Ridge, which displays an interesting rubbly texture. The rover's current location is the closest we will ever get to this side of the ridge, so it was a high priority for the team to image this outcrop before driving away. A short Navcam dust devil movie will continue our regular monitoring of dust-lifting vortices in Gale crater.

In order to facilitate planning tomorrow, the team also included various post-drive observations, including standard Navcam mosaics, a Mastcam workspace survey and stereo image, and a ChemCam AEGIS observation which should provide even more geologic context for assessing tomorrow's workspace. Hopefully these data combined with the chemical analysis of "Hallaig" will help us determine whether we will be able to drill in this area or if we will have to continue driving in search of our next drill target.

This Navcam image acquired on Sol 2412 shows a portion of the ripple field we explored over the weekend, as well as some of the rubbly material comprising the southern side of the Vera Rubin Ridge. This outcrop will be the target of a higher resolution Mastcam stereo mosaic planned today.

The sol 2408 plan ended with the rover using its front wheel to dig a small trench in a ripple at the ripple field named "Rigg." That means today's plan is focused on studying what that scuff uncovered. There is a lot that we can learn from these patches of active sand that we occasionally encounter as we explore Gale crater!

One of the big questions is where the sand comes from: by measuring the chemical composition of the sand at Rigg we can compare with sand we have seen earlier in the mission to see if the chemistry is different enough that there must be different sources. We also can compare the grain sizes in different parts of the ripple to get a better understanding of how the wind sorts sand grains under martian gravity and atmospheric pressure.

Studying the shape of the ripples in detail also helps us compare modern bedforms (the generic term for dune-like features of all sizes) to the ancient ones we see preserved in the rocks, which lets us infer similarities or differences in the environment. And of course, looking closely at these wind-blown sand features lets us get a better handle on what the winds are like in Gale crater right now.

The sol 2409 plan starts off with a Mastcam multispectral observation of the scuff, followed by ChemCam of the floor ("Ben Cruachan") and wall ("Ben Lomond") of the scuff, as well as the undisturbed crest of the ripple ("Ben Suardal"). We'll then use Navcam to look for dust devils before starting contact science.

Our contact science observations start with MAHLI images of targets on the ripple crest ("Dunoon"), trough ("Gairsay"), and a secondary ripple ("Nairn"). APXS will then quickly measure the chemistry of Dunoon before settling in for an overnight measurement of Gairsay. We plan to keep playing in the sand at Rigg for another couple of sols before moving on toward a blocky outcrop to the northeast.

Now that we're back on the road following our drill campaign at Kilmarie, Curiosity is planning a quick "touch-and-go" activity today to characterize the local bedrock. Yesterday afternoon, Curiosity drove a short 3 meters to the north towards a large ripple field named "Rigg," which is where the "go" portion of today's "touch-and-go" will take her this afternoon. Before then, however, Curiosity will extend her arm and analyze a patch of bedrock with the Alpha Particle X-ray Spectrometer (APXS) and then zap some more bedrock off to the starboard side of the rover using the ChemCam Laser Induced Breakdown Spectrometer (LIBS) instrument. She'll then proceed with a well-planned dance that will dip one of Curiosity's wheels into the nearby sand ripples, scuffing the surface and creating a small trench, and then orient herself in a position that will be better suited to study both the disturbed and undisturbed portions of the ripples. The next few days will be dedicated to studying these ripples before Curiosity plans to investigate more of the clay-bearing materials of the Glen Torridon region to the south and east of Vera Rubin ridge.

We're driving today! …but only about three meters.

After weeks of staying put while we completed drilling activities at "Kilmarie," Curiosity is stretching her wheels. The main activity in the sol 2407 plan will be a set of MAHLI wheel images, followed by a very small bump forward to place DAN over the Kilmarie drill hole. We hope to take an active DAN observation right over the drill hole to understand more about the hydration state of the rock and subsurface. We'll also squeeze in a bit of science around the drive activities today, including a retake of the Mastcam multispectral image of Kilmarie before the drive, and a ChemCam AEGIS target afterwards.

Today we developed a 3 sol plan geared towards wrapping up activities at the "Kilmarie" drill site. We learned early on that the SAM team decided to not proceed with a wet chemistry experiment at this site, which would have required us to drill a third sample. As a result, we finished analyses of the Kilmarie drill hole with MAHLI imaging of the drill hole and tailings and APXS measurements over two regions of the tailings. One APXS spot will be over a redder portion of the drill tailings (see image above), and the other APXS spot will be over the paler portion of the tailings (which also tends to appear as clumps in the above image). Acquiring two APXS measurements over these different areas may tell us whether these two colors represent differences in composition.

On Sol 2405, we will take a MAHLI selfie of the rover, giving us a nice view of the "Aberlady" and Kilmarie drill holes and the landscape of the Glen Torridon region. We will also measure the redder portion of the Kilmarie tailings with ChemCam, which will provide a comparison with the APXS data acquired over that region. Also in the plan is a suite of ChemCam observations on bedrock and pebble targets in order to continue documenting the textural and chemical transition between coherent bedrock and rubbly materials in Glen Torridon. In particular, three targets - "Stotfield," "Tiffany 3," and "Pennan" - are concentrated near an area where bedrock appears to transition to pebbles, and "Shalloch" is a target focused on a farther patch of rubbly material. There are also several environmental observations spread throughout the plan, such as zenith movies, Mastcam taus, and Navcam dust devil surveys to monitor the atmosphere, as well as a MARDI observation to close out the change detection campaign at this drill site.

Navcam left image of APXS analyzing Kilmarie prior to drilling. Note the Aberlady drill hole on the block to the left.

We got the go ahead at the start of planning to proceed with dumping the Kilmarie drill fines from the drill bit assembly. Both the SAM and CheMin instruments have completed or are nearing completion of analyses of the pulverized Kilmarie sample and it is now the turn of APXS and MAHLI to analyze the material. As a member of the APXS team and the strategic planner today for our instrument, I was excited to use APXS and to start analyzing the drill fines. We have been waiting patiently to use APXS and MAHLI, because any arm activity is precluded while sample is in the drill bit assembly. The chemical analysis of the dumped material by APXS and eventually ChemCam will be compared with that of the bedrock surface prior to drilling, as well as to the nearby "Aberlady" drill fines, to look for variations in composition with depth and between the two drill holes. Specifically, the APXS-derived chemistry of the dumped material will be used by the CheMin team to refine their mineralogical analysis. The close-up imaging by MAHLI will tell us about the texture and colour of the fines in detail and assist the APXS team in determining exactly where our instrument was placed. MAHLI will also image the drill hole and tailings (powdered rock material surrounding the drill hole) at a 25 cm standoff to assist placement of APXS and closer-up MAHLI imaging in the next plan. Mastcam multispectral imaging and ChemCam passive spectroscopy of the Kilmarie dumped material will aid in further elucidating mineralogy.

Aside from concentrating on the dumped Kilmarie drill fines, the plan included two ChemCam 5x1 active LIBS analyses to further characterize the transition between compositional end-member bedrock types exposed in the area (targets "Valtos" and "Wishaw"). A ChemCam experiment was also planned in order to test a new way of protecting ChemCam from being damaged by inadvertently pointing at the sun. The new method allows ChemCam to take advantage of local terrain features to block the sun, allowing the instrument to target more distant features than if it had to stay below an imaginary, level horizon.A Mastcam mosaic will add to images already acquired of a nearby ripple field, where we are planning to conduct a more detailed study in the near future.

Environmental observations included standard background REMS activities to monitor the daily martian weather, RAD to monitor the radiation environment and DAN passive to study the abundance and distribution of subsurface H- and OH-bearing materials. A Navcam suprahorizon movie will look for clouds and optical depth of the atmosphere and a Mastcam tau observation pointed towards the sun will measure atmospheric opacity.

Clouds visible in a raw Mastcam image taken at about 4pm local true solar time on sol 2393.

Mars is steadily moving toward the cloudiest time of year at low latitudes, which occurs from about southern mid fall through mid winter. This means that right now, just over 40 Mars sols after fall equinox, we're expecting to see the cloud cover increasing, especially at the times of day when air temperatures are cooler. The image shows thin clouds, probably made of water ice, that are visible in a raw Mastcam image taken at about 4pm local true solar time on sol 2393.

In the previous plan, we added some Navcam cloud movies just after sunrise in Gale Crater. But in the current plan, we added a Navcam north-facing 'twilight' movie to look for clouds right after sunset. A nice side benefit is that we may be able to estimate the altitude of any clouds we observe, if we see them 'fade' during the movie. This is because the clouds will only appear bright if they're still receiving direct sunlight, and the time at which that ceases depends on how high they are above the surface. This is also a particularly good sol for taking north-facing cloud movies, because InSight - Curiosity's 'neighbor' a mere 600 kilometers to the north - will be taking some south-facing images at the same time. So in theory, both missions might see the same patch of clouds, provided they're high enough!

Other environmental activities in this plan include standard REMS, DAN passive, and afternoon cloud movies. We also added a Mastcam column opacity measurement and two dust devil activities: a 360° survey and a movie.

Down on the surface, CheMin will continue to analyze some of the sample taken from the "Kilmarie" target, which sits within more coherent bedrock, while the small remainder of the drill sample will be dumped onto the surface in a 'portion to exhaustion' activity. We also added repeat Mastcam imaging of the Kilmarie drill tailings, which we can compare with previous images to gain some idea of the wind strength and direction at our current location and season.

ChemCam will also be busy in this plan, with a long distance Remote Micro-Imager (RMI) mosaic of target "Pediment 2400a" as well as observations on some of the broken-up bedrock fragments around the rover, specifically "Delnabo 2," "Pitcaple," and "Dumyat 2," with Mastcam taking context images of the same three targets. The Mastcam ripple field mosaic couldn't be completed in today's plan, due to the arm being in the way, so the final images will now be taken in the plan that follows.