Sol 1726 update by Michael Battalio: First Look at Vera Rubin Ridge (13 Jun 2017)

After great anticipation over the last few weeks, the drive in the current plan will bring us into position for stop 1 of our close look at the northern face of the hematite-bearing Vera Rubin Ridge. Mastcam will take a wide mosaic to begin documenting the sedimentary structure of the ridge. GEO will take several observations of nearby targets before the drive. ChemCam will target "Mount Abraham" (bedrock on the top left in the above Navcam image) and "Mount Redington" (bedrock at top center), both of which are typical members of the Murray bedrock. Mastcam will image each of those targets as well, along with the target "Marsh Head," an area of exposed stratigraphy. GEO activities finish with Navcam documentation of our new position and MARDI imaging.

I was the ENV STL for this plan, and only one ENV cadence observation will be obtained. A 4-frame Navcam dust devil survey will be taken around noon to continue to document vortex activity as we climb Mt. Sharp. REMS will capture the usual top of the hour 5 minute observations, along with 9 hours of extended observations. DAN will take a 20 minute post-drive observation and just under 5 hours of passive observations.

Sol 1727 Update by Rachel Kronyak: Little bit of everything (14 Jun 2017)

After a successful drive, our parking spot included a nice patch of Murray bedrock to allow us to perform contact science (MAHLI and APXS) in today's plan. Our target for contact science is "Jones Marsh," a dark patch of the Murray that you can see just above the rightmost corner of Curiosity's mast shadow in the Navcam image. The GEO group also planned a suite of observations of Vera Rubin Ridge (VRR), which we're making great progress towards. Mastcam will perform a multispectral observation on "Freeman Ridge," a small butte just in front of VRR that shows interesting color variations. ChemCam will then take a mosaic of VRR using its Remote Micro-Imager (RMI) to complement the Mastcam mosaic we took in yesterday's plan. We will take an additional Mastcam mosaic of "Spaulding Mountain," an area of exposed Murray formation blocks along our drive path.

We will then complete a drive, do some post-drive imaging of our new location, and finish up today's plan with some environmental observations. These include tau, line-of-sight extinction, and sky survey measurements with Mastcam to assess how much dust is in the atmosphere. We will also perform our standard REMS and DAN activities.

Today I served as a PUL-1 for Mastcam. With VRR on the horizon and the fantastic Murray formation underneath our wheels, there is never a shortage of things to image!

Sol 1728 Update by Rachel Kronyak: Remote science and drive on (15 Jun 2017)

After a busy day of contact science yesterday, today's plan was dedicated towards remote science and driving. As Mastcam PUL-1 today, I was fairly busy helping put together a suite of Mastcam images for Curiosity to take. These included mosaics of "Preble Cove" and "Fernald Point", some nice blocks of the Murray formation just in front of the rover (Fernald Point is the block just in front of the rover wheel in the Navcam image above). We'll then take a few images of "Freeman Ridge" to follow up on yesterday's multispectral observation.

We also planned a series of environmental observations, including our standard REMS and DAN, as well as a ChemCam passive sky, Mastcam tau, and line-of-sight extinction. We'll then continue driving towards Vera Rubin Ridge and take some post-drive images to set ourselves up for an exciting weekend of more remote and contact science!

Sol 1729 - 1731 update by Abigail Fraeman: Roving Right Along (17 Jun 2017)

The drive on Sol 1728 was successful, and our weekend plan will be chock-full of activities. On the first sol, we will do some contact science on the rather colorful workspace that is currently in front of the rover. We will be collecting MAHLI and APXS observations of two targets, "Frazer Creek" and "Lurvey Spring." We will also collect some ChemCam observations of "Mark Island" and Frazer Creek plus the corresponding Mastcam documentation images of these targets. Finally, we will take a full multispectral filter Mastcam observation of Mark Island, as well as additional Mastcam images of targets "Big Spencer Mountain" and "Monument Cove."

Curiosity will wake up around 3 in the morning between the first and second sols of the plan to make a special observation of Mars' moon Phobos. We are going to watch Phobos as it emerges from Mars' shadow into sunlight. This will help us measure the amount and size of dust particles in Mars' upper atmosphere. After the sun rises on the second sol of the weekend plan, we'll do full MAHLI wheel imaging (or FMWI in rover-acronym speak). We take images of our wheels using MAHLI throughout a full wheel rotation every few hundred meters to track the rate of wheel damage.

On the third sol of the plan, we will drive and have a post-drive ChemCam AEGIS observation and dust devil search. The drive will place us ~35 meters closer to the second Vera Rubin Ridge approach-imaging stop. The data Curiosity collected during the first imaging stop earlier in the week have been coming down over the last few days, and they look absolutely spectacular. For example, a portion of the ChemCam RMI mosaic we took of the lower most layers of the ridge show a lot of fine-scale layers. I mapped Vera Rubin Ridge using orbital data as part of my PhD thesis five years ago, so it's been so exciting for me to see these images after staring at the area from above for so long. The fine scale details that we'll be able to collect using Curiosity's instruments will help us understand how Vera Rubin Ridge formed, and any implications for past habitable environments at Gale Crater.

Sols 1732-1733 update by Mark Salvatore: Marching Ahead towards Vera Rubin Ridge (19 Jun 2017)

As this is my first time contributing to the MSL blog, I'd like to quickly introduce myself to you all. I'm Mark, an MSL Participating Scientist and a faculty member at Northern Arizona University, trained in geochemistry, spectroscopy, and remote sensing. I'm excited to help walk you all through the daily endeavors of this wonderful rover and mission!

Curiosity continues to make progress along its planned ascent route up Mt. Sharp, and is quickly approaching the hematite-bearing Vera Rubin Ridge. As a refresher, Vera Rubin Ridge is a high-standing unit that runs parallel to and along the eastern side of the Bagnold Dunes. From orbit, Vera Rubin Ridge has been shown to exhibit signatures of hematite, an oxidized iron phase whose presence can help us to better understand the environmental conditions present when this mineral assemblage formed.

Over the weekend, Curiosity drove approximately 32 meters and parked in front of a large rocky slab (about the size of a large dining room table) with smaller rocky patches nearby, perfect for our continued documentation of the local bedrock. This slab will be extensively imaged using Mastcam. In addition to imaging, three rocky targets will be chemically analyzed by the rover. "Pierce Head" represents an unremarkable piece of the Murray formation, and will be investigated using ChemCam and APXS (and MAHLI context imaging) to fully characterize the bedrock chemistry at this location. Alternatively, "Mosely Point" and "Leland Point" appear darker in tone and exhibit slightly rougher and smoother textures, respectively, and will be investigated using only ChemCam.

Following these analyses, Curiosity will set off on another drive over rough terrain to the east, where the rover will document its surroundings using its automated ChemCam targeting capabilities and its suite of cameras. In particular, the rover will turn its cameras to Vera Rubin Ridge for another suite of high resolution color images, which will help to characterize any observed layers, fractures, or geologic contacts. These observations will help the science team to determine how Vera Rubin Ridge formed and its relationship to the other geologic units found within Gale Crater.

Another super interesting observation that will be made during this planning period is an opportunistic nighttime astronomical observation of Mars' smallest moon Deimos, which will be imaged using Mastcam. Even though Deimos is only ~8 miles in diameter, Mastcam's incredible resolution and pointing capabilities make these observations seem routine. Imaging Mars' moons allows scientists to better understand the evolution of their orbits over time.

We are currently in a phase of "restricted planning," where the offset in time between the Earth and Mars prohibits our ability to downlink data with sufficient time to plan on a daily basis. So, the science and engineering teams planned two days' worth of rover activities today. We will reconvene on Wednesday to produce a similar two-day plan, and will do so through next week. Despite this offset, the crafty and efficient science and engineering teams are able to successfully create rover plans that ensure Curiosity is busy as it continues its journey up Mt. Sharp.

Sols 1734-1735 update by Mark Salvatore: Gazing Longingly towards Vera Rubin Ridge (21 Jun 2017)

Curiosity continues to drive to the east-northeast around two small patches of dunes that are positioned just north of Vera Rubin Ridge. Once beyond this easternmost dune patch, the plan is for her to turn to the southeast and towards the location identified as the safest place for Curiosity to ascend the ridge. Currently, this ridge ascent point is approximately 370 meters away, which is less than the exterior length of Wembley Stadium in London. If only the path ahead were as smooth as a soccer pitch!

After a ~15 meter drive, Curiosity is situated in front of several small patches of rock about the size of large textbooks. This front Hazard Avoidance Camera (Hazcam) image shows today's view, with Mt. Sharp in the background and a portion of Vera Rubin Ridge in the upper-right corner. One of these rocks, a target known as "Pecks Point" exhibits some interesting variations in brightness, and so its chemistry will be analyzed using the APXS and ChemCam instruments, and it will be imaged using both MAHLI and Mastcam. The remainder of the science for this plan is focused on gazing longingly towards Vera Rubin Ridge. From this vantage point, we will be acquiring imagery of the northern exposure of the ridge (named "Northern Neck") using several techniques. First, we will use the multispectral capabilities of Mastcam (see below for more details) to investigate any possible compositional variations observed within this lower ridge material. Next, we will take a series of overlapping high-resolution images using ChemCam's remote microimager. Although these images won't cover the entirety of the exposure, they will allow scientists to interrogate the fine-scale sedimentary structures present within the ridge. Lastly, we will again turn to Mastcam to image the entirety of "Northern Neck" in true-color, similar to how your eyes would perceive the ridge if you were standing on the surface.

After this science imaging, Curiosity will again take off driving towards the east-northeast. The following day, Curiosity will image the rover deck using Mastcam, hunt for dust devils using the navigation cameras, and acquire additional chemistry data of local targets using ChemCam's automated target selection software known as AEGIS. The science and engineering teams will again reconvene on Friday to formulate the weekend's science plan.

I want to provide a little more context regarding the multispectral imaging capabilities of Mastcam. The cones in a human eye are sensitive to blue, green, and red wavelengths of light which, combined, allow us to see the full range of visible colors. Using a series of filters, Mastcam is able to finely control the wavelengths of light that enter the camera. This means that we can accurately calibrate the data to quantify how surfaces reflect specific wavelengths of light. In addition, Mastcam can record wavelengths beyond the sensitivity of the human eye in the near-infrared, and this additional information can be used to further investigate the composition of the martian surface. Just like how table salt is white and garnets are red, other geologic materials exhibit unique signatures in the infrared as well. As a result, Mastcam is an extremely useful geologic tool onboard Curiosity, as it allows us to investigate differences in the composition of distant surfaces.

One of the key compositional properties of Vera Rubin Ridge is the presence of the iron oxide phase hematite, as determined from orbital observations. Iron oxides are the primary constituents of rust on Earth, which can exhibit spectacular variations in color, and so identifying and characterizing minor color variations throughout the ridge will be important as the mission continues towards the ridge. What is the lateral and vertical distribution of these unique iron oxide phases? Do they vary significantly over the rover's traverse? These questions (and many more) will continue to be the focus of the MSL science team for months to come!

Sol 1736-1739 update by Michael Battalio and Mark Salvatore: A Roving Astronomer (23 Jun 2017)

Curiosity has presented us with another beautiful workspace following a 16.6 meter drive. The majority of this week's activities were focused on imaging Vera Rubin Ridge to observe its stratigraphic and structural relationship to the underlying Murray formation. This weekend's plan is a bit of a deviation from that, as we will be making numerous measurements of the local Murray formation. These "local" observations will be extremely valuable over the coming weeks, as Curiosity potentially transitions between two different geologic units (the Murray formation and Vera Rubin Ridge). The nature of this transition will hold important clues into the origin of the ridge and the evolution of Gale Crater as a whole.

Curiosity will first use ChemCam to probe the composition of three rocky targets, followed by acquiring high-resolution Mastcam images to document the targets. The first target, known as "Winter Harbor," is situated in front of the rover. This target is a benign, flat, and finely layered piece of the Murray formation. Next, ChemCam will target "Beaver Dam Pond," which appears to be a block of the Murray formation that may have been tilted on its side. Curiosity will then point her mast just off her back right wheel, where ChemCam will investigate "Kitteredge Brook," which is a more plate-like and fractured block that appears to have a vein running through it. Lastly, Mastcam will image one additional block of typical layered rock of the Murray formation known as "Crippens Brook." The exposed layering of this target will help determine whether this section of the Murray formation is similar or different than previously analyzed locations.

After these remote observations, Curiosity will untuck her arm and engage in contact science with the "Winter Harbor" target. First, the Dust Removal Tool will be used to brush away any surface dust. Curiosity will then deploy APXS to the target, which uses the decay of the radioactive element curium to generate alpha particles and X-rays that interact with the surface material. The energy recorded coming from the surface material as a result of these interactions holds important clues into the chemistry of the surface materials. Curiosity will leave the APXS instrument in contact with "Winter Harbor" overnight to integrate its signal and to derive a precise measurement of the material's composition.

The next sol, Curiosity will investigate the chemistry of one more target ("Blunts Point," a wavy and fractured block) using ChemCam, take two contextual Mastcam images of this target, and take an additional three Mastcam images of a separate block slightly closer to the rover known as "Blunts Pond," which appears similar in texture to "Blunts Point." Mastcam will then acquire a full multispectral image of "Winter Harbor" before departing this location to the east.

Curiosity will also take multiple environmental observations in this plan. On Sol 1738, a morning imaging suite will be taken, which will include two Navcam cloud movies - a zenith movie looking directly above the rover and a supra-horizon movie looking towards the rim of Gale Crater. Mastcam will capture tau and LOS measurements to assess the amount of dust in the atmosphere. Later on Sol 1738, Mastcam will repeat the tau and LOS pair twice to determine diurnal variability in the atmospheric opacity. The plan will also include MAHLI imaging of the REMS UV sensor to determine the amount of dust on the UV photodiodes, which is done approximately every 60 sols (for more on this periodic activity, see Sol 1674). REMS and DAN measurements will be taken according to the usual cadence.

Curiosity will be an astronomer again in this plan as Mastcam will take images of both of Mars's moons, Phobos and Deimos. Deimos imaging will assist in more accurately defining the moon's orbit, so is not constrained in timing during the night. The imaging of Phobos will capture its ingress into the shadow of Mars - a Martian lunar eclipse. This specific astronomical event occurs repeatedly at this time of year, but the timing of the imaging must be exact. Imaging before the eclipse begins and during the ingress allows for an estimation of the size and amount of dust in the upper atmosphere of Mars. This is possible because as eclipse begins, the light that is reflected off of Phobos must skim through the top of Mars's atmosphere first. This light can then be compared to imaging before eclipse begins. Repeating the Phobos observation at different times of year allows for probing of the atmosphere over different locations and at different altitudes due to the relative geometry changing.

Extra link to image of previous Phobos eclipse ingress on Sol 964 >>

Sol 1739 - 1740 update by Abigail Fraeman: More Touch and Go on the Way to Vera Rubin Ridge (26 Jun 2017)

This past weekend, Curiosity continued to journey east along the contact between the lower portion of Vera Rubin Ridge and the Murray formation with a drive that was a little over 20 m long. Today we worked on planning two sols, Sol 1739 and Sol 1740. On the first sol, we will take MAHLI and APXS observations of a target named "Rice Point" in our continuing quest to characterize the variability of typical Murray bedrock as we ascend Mt. Sharp. We will also take some remote sensing observations to document changes in texture and chemistry of the rocks in front of us, as well as some nearby sand. We have ChemCam LIBS observations of targets named "Hamilton Pond," "Whalesback," and Rice Point. We will take associated Mastcam images to provide color documentation of the ChemCam targets, as well as Mastcam observations of "Fosters Brook" and "Skillings River." After our morning science block will we continue on our way east towards the location where we can ascend Vera Rubin Ridge. Post drive, we will take a ChemCam AEGIS observation and a special stowed MAHLI observation looking back towards Aeolis Palus to document the landscape of we've traversed across. On the second sol of the plan, we will take some Navcam observations to characterize properties of the atmosphere and to search for dust devils.

All of the data from our second imaging stop back on Sol 1734 finished coming down over the weekend, and they continue to show spectacular views of vertical bedrock exposures. We are analyzing these images to understand the nature of the geologic contact between Vera Rubin Ridge and the Murray formation, as well as the environments that deposited the layers that make up the lower ridge. We have been utilizing several of Curiosity's cameras to help with this imaging campaign. We took untargeted, post-drive Mastcam left eye images the sol before the main imaging sol to get a good context and to help us refine pointing for the Mastcam right eye images, which have higher spatial resolution but smaller fields of view. We also took pictures of select sections of the area with the ChemCam Remote Micro-Imager (RMI) that have even higher spatial resolution than the Mastcam right images, but which are black and white only. The science team will use all of these data to perform our analyses.

Ridge images from Mastcam left eye >>

Ridge images from Mastcam right eye >>

From ChemCam RMI >>

Sols 1741-1743 update by Mark Salvatore: "Cat Sized Island" (28 Jun 2017)

Last evening (June 27) between 8pm and 9pm PDT, Curiosity drove approximately 34 meters to the east to position herself just north of a large field of ripples on her way closer to ascending the iron oxide-bearing Vera Rubin Ridge. As Curiosity progresses towards the east, scientists back on Earth continue to look for opportunities to both gaze ahead towards interesting locations on the ridge itself, in addition to looking at the local rocks and sediment surrounding the rover. As we approach the lower units of Vera Rubin Ridge, our measurements of the "typical" rock that surrounds the rover will be vital to helping scientists understand how and why the ridge is different than the other units that have been investigated thus far in Gale Crater. Are we going to observe a very sharp transition in the composition and textures of rocks as we cross the threshold between the underlying mudstones of the Murray formation and the lowermost units of Vera Rubin Ridge? Or, alternatively, are we going to see a very subtle transition that might have gone unnoticed if not for the methodical measurements made upon approaching the ridge? Only time will tell, but we are making sure that we have the information necessary to definitively understand the nature of this transition.

Our science plan for the next two days begins with firing the ChemCam laser at a bedrock target right in front of Curiosity known as "Cat Sized Island". The rock is almost a meter in length (more of a bobcat size than a standard house cat) and shows some interesting nodular textures that the science team wants to investigate further. Following this measurement, two different regions of Vera Rubin Ridge itself will be imaged using the ChemCam high-resolution Remote Micro-Imager (RMI). These measurements and observations will be followed up with color images collected by Mastcam for general documentation of the ridge, "Cat Sized Island," and the ChemCam target that was automatically analyzed after yesterday's drive.

Following these measurements, Curiosity will again take to the road and head further east northeast, positioning herself towards the northernmost tip of the nearby sand ripple patch. In the next few days, the plan is to turn Curiosity towards the east southeast around these ripples and towards the ideal location to begin the climb up Vera Rubin Ridge, which is still another ~275 meters distant.

The rover team is still operating under restricted planning conditions this week, which occurs when the offset in time between Earth and Mars prohibits the team from acquiring, downlinking, and analyzing the data collected by the rover with sufficient time to generate and uplink a science plan to the rover on a daily basis. In addition, with the Fourth of July holiday early next week, today's plan includes activities for three days on the Martian surface. Following Curiosity's drive, she will acquire her standard Navcam imagery surrounding the rover to allow Friday's science planning team to have a good view of the area accessible to the rover and the instruments. ChemCam will also acquire a LIBS analysis of an automatically selected target, and will also acquire passive spectra of several calibration targets onboard the deck of the rover. Lastly, MAHLI will image a tray on the rover deck that has been collecting windblown sand to help scientists better understand the properties of these particles and how the local winds are able to move materials. Curiosity will then turn in for the evening, but will wake up around 4:30am local time to image Deimos using the Mastcam instrument. The next morning, Curiosity will resume her science activities with a series of ChemCam passive observations of calibration targets on the deck of the rover, as well as Mastcam imaging of the rover deck to check on the hardware and monitor debris cover.

On the afternoon of the second day, Curiosity will acquire additional images that have become a familiar and consistent component of the rover's scientific investigation. The fixed and immovable Mars Descent Imager, or MARDI, will acquire a suite of images looking just below the rover's belly. MARDI acquired high-resolution video at four frames per second during Curiosity's descent to the Martian surface, and while its primary objective was completed the moment Curiosity landed safely on Mars, MARDI has since been used to perform surface science. MARDI routinely collects images of the ground immediately beneath the rover to characterize the physical properties of both rocks and sediment as the rover travels through Gale Crater. Because of its consistent viewing geometry and spatial resolution of approximately one millimeter per pixel, MARDI image acquisition has become a routine and integral component to our scientific investigation of the landscapes immediately surrounding Curiosity rover as she continues her journey up Mt. Sharp.

The third and final day of this observation plan will be dominated by environmental monitoring using both the Navcam and Mastcam instruments. First, Navcam will acquire several images to hunt for dust devils in Gale Crater. Then, Mastcam will acquire images of the rim of Gale Crater to investigate the amount of dust in the Martian atmosphere. Lastly, Navcam will point nearly straight up and acquire several images over several minutes to observe any possible clouds in the sky and their movement due to atmospheric winds. These observations will be used by scientists to improve our understanding of atmospheric processes on Mars and the specific atmospheric conditions present in Gale Crater.

Sol 1744 update by Christopher Edwards: Up the Vera Rubin Ridge and Around the Sand Trap (30 Jun 2017)

I was the Surface Properties Scientist, or SPS, on staff again today. After completing a successful drive, Curiosity arrived at a nice workspace to carry out the weekend plan. Today's planning activities were for a three sol plan, where the weekend activities were scheduled, including several arm activities and a drive for the last sol of the plan.

The two arm activities included the targets "Mingo" and "Jobbies", each of which were located on Murray bedrock exposures. The Mingo target was chosen for a DRT because of its relatively smooth nature, making it suitable to brush the ever-present Martian dust away. The Jobbies target seemed to have a darker, gray toned appearance that intrigued the science team on shift today. Supporting remote sensing science was planned of the scene and will be used to both give context to the contact science and help continue finding a path up the Vera Rubin Ridge.

As SPS, today I worked with rover planners to help identify a clear path up the Vera Rubin Ridge, avoiding large, steeply dipping rocks to the left of the rover and dodging a big sand trap to the right of the rover. These features can be seen in the Navcam image shown, where the rover will drive just to right of the layered rock on the upper left side of the image. It turns out the best path forward was to put the rover wheels on either side and drive right over the top of a rock that was about 33 cm in height! This lone rock can be seen on the middle left hand side of the included Navcam image. This rock is no problem for Curiosity since it has plenty of clearance and will drive smoothly over this obstacle.

Sol 1747 update by Scott Guzewich: Martian Fruit Salad (5 Jul 2017)

As is typical for Curiosity lately, today we planned a "touch-and-go" suite of activities for the rover. Today I served as the Science Operations Working Group Chair. A high level of charge in Curiosity's batteries after the long holiday weekend allowed us to prepare a bounty of science observations. The first activity was contact science, a mix of APXS and MAHLI, on a target named "Appledore" which is believed to be Murray bedrock much like we've examined before. This was followed by a Navcam survey for dust devils on the slopes of Mt. Sharp and then ChemCam targets on "Sugar_Plum" and "Whortleberry", the latter of which appears to be a dark-toned pebble mixed into the light-toned Murray bedrock. We additionally scheduled a ChemCam passive observation, i.e., one without using the laser to vaporize small bits of rock, on a promontory of Vera Rubin Ridge (the taller point near the center of the image). We also targeted some interesting layered structures with Mastcam at the "Gooseberry" target.

Following this full plate of science activities, Curiosity will drive about 10 meters toward a sand ripple that we plan to study over the coming weekend. This may be the last sand dune field Curiosity can closely examine for a long while, so we plan to make the most of it!

Sol 1748 update by Ken Herkenhoff: Bumping to a sand ripple (6 Jul 2017)

Another touch-and-go was strategically planned for today, and there is bedrock in the arm workspace, so the tactical science team selected a block named "Tupper Ledge" for contact science. After APXS measures the elemental chemistry of Tupper Ledge and MAHLI takes a full suite of images of the same target, the arm will be stowed to allow ChemCam and Right Mastcam observations of a soil target called "No Mans Land" and a bedrock target dubbed "Sugar Loaves." Navcam will search for clouds above the horizon and the Right Mastcam will snap a couple pictures of "Harris," a trough in the dark sand.

Today's drive goal is to place the crest of a sand ripple in the arm workspace, to allow contact science on the ripple this weekend. A wheel scuff of the ripple was added by the Rover Planners, which should allow the interior of the ripple to be observed. After the drive and standard post-drive imaging, Navcam will search for clouds overhead and DAN will make another active measurement of hydrogen in the near-subsurface. Once again, the tactical team did a great job, so it was an easy day for me as SOWG Chair.

Sol 1748-1752 update by Michael Battalio: Kicking up Some Sand (7 Jul 2017)

Curiosity has intentionally scuffed a nearby sand ripple, which has gifted the team with an exceptional view of the interior of these small sand deposits. The majority of the weekend's activities will consist of lots of targeted science on the scuff, as there is no nearby bedrock for Curiosity to observe. This is in contrast to the past week where quick documentation of local changes in stratigraphy of the bedrock as we drive closer to Vera Rubin Ridge was the priority.

Several targets were selected for observations around the scuff including the undisturbed ripple crest that is grayer with coarse grains, "Enchanted Island," the undisturbed ripple side that is redder and finer-grained, "Thomas Little Toes," and the wall of the scuff that cuts through the ripple, "Ile Damour." These targets will be imaged by MAHLI, with particular focus on imaging the wall of the scuff to detect any layering within the interior of the ripple that has been uncovered. APXS will perform extended integrations on Thomas Little Toes and Enchanted Island. Unfortunately, an APXS integration will not be performed on Ile Damour, and MAHLI will remain 5 cm away from this target to ensure safety of the instruments by not bringing the arm too close to the ripple at the risk of the side of the ripple collapsing. Mastcam will also image these areas for comparison of grain size, color, and composition to previously observed ripples. Finally, ChemCam will target Enchanted Island for comparison to two other ripple crest targets and Ile Damour to detect differences in grain size and composition in comparison to the targets on the ripple surface.

Two other areas along and near the crest of the un-scuffed ripple will be targeted by Mastcam and ChemCam. "Verona" is slightly away from the crest of the ripple, and "Merrymeeting Bay" is at the base of the ripple crest. These two additional targets were selected to compare differences in grain size and composition and detect changes in color across the surface of the ripple. An interesting wrinkle in planning was ordering the observations so that ChemCam activities on the wall of the scuff (the Ile Damour target) occurred after any imaging from MAHLI, in case actively shooting the fragile wall side disturbed or shifted the sand along the scuff wall.

Before the science activities with the arm, Curiosity will take a rather unusual selfie of sorts by pointing MAHLI directly into the eye of Mastcam to look at the Mastcam sunshade. This measurement is being taken to ensure that grains of sand are not interfering with Mastcam tau measurements.

Finally, Curiosity will drive away from the sand ripple to make some progress towards the next stop in the Vera Rubin Ridge imaging campaign before conjunction. Mastcam and Navcam will take standard post-drive imaging.

As ESTLK, I ensured that ENV also took a bevy of observations over the weekend. Navcam will take four observations for ENV. First, two different dust devil surveys will be taken to attempt to observe any nearby convective vortices. One of these surveys will take three consecutive images at each of three aims 120 degrees apart to capture a 360 degree field of view. A second 4-frame dust devil survey will take a pair of images at four pointings, each about 40 degrees apart. Second, a line-of-sight measurement directed towards the crater rim will be captured that is similar to the Mastcam LOS to allow for comparison between instruments. Third, a supra-horizon cloud movie will be taken, which is particularly important as we move into the time of year of the aphelion cloud belt, where high-level clouds become much more frequent. Mastcam will capture tau and LOS measurements to assess the amount of dust in the atmosphere. REMS will fit in 20 extended, hour-long blocks, including two HRIM (High Resolution Interval Mode for humid measurements) measurements, and DAN will take the usual passive and post-drive active measurements.

Sol 1752 update by Rachel Kronyak: Sand in our rear-view (10 Jul 2017)

Following a jam-packed weekend of contact and remote science on some beautiful sand deposits, the GEO group opted for mostly remote observations in today's plan. ChemCam will target "Grogg Ledge," a small patch of Murray bedrock in front of the rover. ChemCam will also use its Remote Micro-Imager (RMI) to take a long-distance mosaic of an interesting portion of Vera Rubin Ridge.

After our ChemCam activities, we'll take a suite of Mastcam mosaics to finalize our coverage of the sand deposits that we looked at over the weekend. We'll then drive, take some post-drive images, and perform a post-drive AEGIS observation. Later in the afternoon, we will conduct a SAM Electrical Baseline Test (EBT), which is designed to periodically monitor SAM's electrical functions. We also have a series of ENV activities for today, including standard REMS and DAN during the day, and an early morning suite for tomorrow that includes a Mastcam tau, line-of-sight extinction, and Navcam zenith and suprahorizon movies.

Today my job was the GEO group's Keeper of the Plan (KOP), which is a really exciting and rewarding operational role. As the KOP, I'm responsible for building the activities that GEO would like Curiosity to execute for the day. This involves assessing the terrain around the rover, searching for targets, and selecting observations that will help us achieve our scientific objectives. These tasks require input from all instrument teams and can sometimes get pretty busy!

Sol 1753 update by Mark Salvatore: Wishful Thinking (11 Jul 2017)

The activities planned for Sol 1753 revolve around a quick "touch-and-go" chemistry measurement using the Alpha Particle X-Ray Spectrometer (APXS) instrument on Curiosity's arm. After a ~10 meter drive while most Americans were asleep, Curiosity parked herself in front of another suite of beautifully fractured bedrock belonging to the Murray formation. The rover will begin her morning activities at approximately 9:30pm PDT, and about an hour later will conduct the short APXS measurement and high-resolution MAHLI imaging on a smooth block of the Murray formation known as "Foxbird." Later, the ChemCam instrument will collect chemistry information of Foxbird by ablating five small spots in the target using laser induced breakdown spectroscopy (LIBS) and recording the spectral properties of the generated plasma to determine the chemistry of the target. An additional Murray bedrock target known as "Damariscotta" will be targeted in three locations using ChemCam. The Damariscotta target exhibits beautiful thin layers along its edge, which is the target of this ChemCam investigation. Before driving further east along the nominal Mount Sharp Ascent Route (MSAR), Mastcam will be used to document both Foxbird and Damariscotta in color.

Following a planned drive lasting approximately one hour scheduled to begin at approximately 1:00am PDT, Curiosity will snap some Navcam images of her immediate surroundings before beaming them back to Earth via the Mars Reconnaissance Orbiter spacecraft. After phoning home, Curiosity will then complete her Navcam imaging, will acquire Mastcam images of nearby rock clasts and MARDI images of the terrain immediately beneath the rover, and will conduct a relatively short hunt for dust devils using Navcam.

The second ChemCam target in this plan is named for Damariscotta, Maine, a small coastal town plagued by violent conflicts and skirmishes during the 1600s and 1700s. Damariscotta is home to Whaleback Shell Midden, a huge heap of oyster shells that were discarded by the native populations well before the arrival of Europeans to the region. Digging through this midden reveals layer after layer of loosely consolidated shells that are now incorporated into the local geologic record. Might we one day find a shell midden along the margin of the ancient lake that once filled Gale Crater? Wishful thinking, methinks, but you can count on Curiosity to keep her eyes peeled.

Sol 1754 update by Abigail Fraeman: Science flowing through our veins (12 Jul 2017)

Today on Mars we planned a typical "drive sol" that involved a bit of pre-drive science followed by a drive and some post-drive untargeted observations. There were a variety of light and dark colored veins near the rover that were visible in the Navcam images, so the science team decided to spend our pre-drive science time investigating the chemistry and morphology of these features. The coordinated ChemCam and Mastcam observations we planned on light and dark veins in targets named "Hockomock Bay" and "Hells Half Acre" should get the job done. We'll also take a Mastcam-only observation of dark layers in a target named "High Sheriff."

The next major chunk of time in Sol 1754 will be spent driving towards Vera Rubin Ridge. Today I was staffed as a surface properties scientist, which means I helped advise the rover drivers on any geologic features in the terrain that could present mobility challenges. We'll be driving through a bunch of fractured bedrock and sandy areas as we head closer to our third official Vera Rubin Ridge approach imaging location. Because we've seen such spectacular sedimentary structures in our previous images of the ridge, we decided to try to get as close as possible to the vertical exposures of the lower portion of the Vera Rubin Ridge for this imaging stop - I can't wait until we get there.

After the sol's drive finishes, we'll take an automatically targeted ChemCam AEGIS observation along with standard post drive Navcam images and a clast survey. We'll also snap a quick picture with the stowed MAHLI that should give us a great view to the north back towards where we started from on Aeolis Palus almost five years ago. All in all, Sol 1754 should be a very productive day on Mars.

Image of the day:

https://mars.nasa.gov/msl/multimedia/raw/?rawid=NRB_553120980EDR_F0642442NCAM00312M_&s=1753

A previous MAHLI end of drive stowed image:

https://mars.nasa.gov/msl/multimedia/raw/?rawid=1739MH0003250050700186E02_DXXX&s=1739

Sol 1755 update by Roger Wiens: Getting Ready to Disappear Behind the Sun (13 Jul 2017)

Planetary scientists take their vacations when the planets align. In our case it is because communications with Mars are blacked out when the red planet goes behind the sun. It is called a solar conjunction. Afterwards, Mars will re-appear in our terrestrial skies early in the morning, just before sunrise. As the Earth chases the Red Planet, Mars will rise earlier until at opposition, when the Earth passes Mars a little over a year from now, the Red Planet will be directly overhead at midnight, e.g., directly behind Earth, relative to the sun.

For the Curiosity rover team, we will cease operations this weekend. There is one more day, tomorrow, for some instruments, while others like arm instruments and ChemCam cut out early, as we want to verify it is sun safe (its focus stage parked at a safe position) before we leave the rover on its own. The team will check on the rover on August 4 and re-start full operations on August 7. In the meantime, Curiosity might just get lonely.

Yestersol's drive was 38 meters, bringing the mission total to just over 17 km. The rover is now facing a steep 20 meter high section of the ridge. The image link shows the front Hazcam view looking straight up the ridge. We won't climb it here; there's a gentler slope to the east.

Today it was decided not to drive any further before conjunction. The rover is on a ~8 degree slope right now and the team didn't want to risk a lot of slip just before conjunction. The team planned the last ChemCams pre-conjunction, with targets "Jimmies Ledge" and "Jennys Nubble." Mastcam will take a 2-image mosaic of the top portion of the ridge and provide documentation of yestersol's ChemCam AEGIS observation. Navcam will be used to make a dust devil movie and a suprahorizon movie looking south.

Sol 1756 update by Michelle Minitti: Closing time (14 Jul 2017)

Today marked the last chance for us to reliably command Curiosity before she, and Mars, disappear behind the Sun for about three weeks. This made today's planning feel as if the Sun were setting on our normally active rover activities, akin to this Martian sunset image from 2015. MAHLI, APXS and ChemCam were already stored safely for the upcoming conjunction nap, leaving Mastcam and MARDI to collect a few last bits of science data for the GEO group. Mastcam acquired mosaics of the "Vera Rubin Ridge" above and in front of the rover, and of the workspace in front of the rover. Both mosaics not only inform us about the rocks around us, they will be used to plan activities right after we return from conjunction. Mastcam and MARDI will acquire images on sols 1757 and 1758 to look for wind-induced changes in the sands around the rover. These change detection images complement similar change detection images acquired at previous sand stops, revealing the dynamic nature of Mars. After imaging on Sol 1758, Mastcam will home her focus mechanisms and settle in for a well-deserved break.

The ENV group had a jam packed plan, acquiring three long Navcam movies seeking dust devils, and Mastcam and Navcam images monitoring the sky for clouds and dust load. The relative lack of other activities in the plan allowed these activities to be spaced out over early morning, mid-day and late afternoon times, giving the science team insight into how time of day influences atmospheric phenomena. DAN will acquire six long (at least one hour) passive observations, and RAD and REMS will continue their steady monitoring of the Gale Crater environment. DAN, RAD and REMS are the only three science instruments that will remain active over conjunction.

In addition to squeezing in science observations, Curiosity will conduct a suite of tests with the drill, another step in the efforts of the engineers to bring the drill back to full functionality. These tests will give the engineers just as much data to chew on over conjunction as the science team!

See you on the flip side, trusty rover!

Sol 1777 update by Ken Herkenhoff: Easing back into mission planning (4 Aug 2017)

As the solar conjunction stand-down comes to an end, we are easing back into operations planning, focusing on Sol 1780, which will be planned in detail on Monday. There was no SOWG meeting today, so it was a very easy day for me as SOWG Chair: We discussed plans for next week and made a few changes. The focus of the Sol 1780 plan will be more diagnostic testing of the drill and our last opportunity to examine the current arm workspace using the remote sensing instruments. Tuesday will be a "soliday," with no tactical planning. The Wednesday (Sol 1781) plan was changed to move the drive earlier, allowing return of more of the data needed for Thursday (Sol 1782) planning. This required deleting the remote science block from the Sol 1781 plan, but a touch-and-go is still planned. We received the data we need to plan contact science and discussed potential targets. So we got a good head start on Sol 1780 planning, and look forward to returning to tactical operations next week!

Sol 1780 update by Michael Battalio: Five (Earth) Years on Mars (7 Aug 2017)

Welcome back to the first full day of operations after conjunction and the fifth anniversary of landing! Curiosity remained healthy over the month long break, so without missing a beat, Curiosity is ready to resume the Vera Rubin Ridge imaging campaign and the trek up Mt. Sharp.

First in this plan, several drill feed tests will be performed and will take up the bulk of the plan's time. The GEO group resumes regular science activities by investigating a couple of targets with Mastcam to look for changes over conjunction, including "Bodge Sands" and "Machias Bay." ChemCam will target "Huckins Ledge" and "Mackerel Ledge," with Mastcam providing additional imaging of those targets. Tuesday is a "soliday" to adjust the timing of the slightly longer Mars day back to a regular Earth schedule, so there will be no tactical planning.

Waiting for conjunction to finish requires patience from everyone, but it is especially frustrating for ENV. Unlike the GEO group who can confidently know that all the science in front of them before conjunction will still be there once regular communication resumes, the weather on Mars keeps happening regardless of whether we actively direct Curiosity to observe or not. So as ESTLK, I included several cadence observations in this first plan back to ensure that the gap of environmental observations was as short as possible. Navcam will image for clouds (like the clouds in the above image from Sol 1758), scan for dust devils across the crater basin, and measure the LOS extinction of dust towards the crater rim. REMS will continue its usual five-minute, top-of-the-hour blocks along with seven hour-long extended blocks, including two HRIM (High Resolution Interval Mode) measurements. DAN will take a long passive measurement.

Sol 1781 update by Rachel Kronyak: Dusting off the wheels and hitting the road! (9 Aug 2017)

Following our month of conjunction and first full day of operations on Monday, we're finally ready to dust off the wheels and get back to driving towards Vera Rubin Ridge. Today was a pretty smooth day of planning, as we're still getting back into the swing of things.

We'll kick off today's plan with a touch and go (MAHLI imaging plus a short APXS analysis) on the target "Mackerel Ledge," which we got our first taste of with ChemCam on Monday. For reference, Mackerel Ledge is located on the small patch of Murray bedrock at the center of the Navcam image above.

We'll then complete our drive, take some standard post-drive images, and perform a SAM Electrical Baseline Test (EBT). Our ENV activities for today include standard REMS and DAN blocks as well as Mastcam tau and LOS extinction measurements.