Field Notes from Mars:
Status Reports for MER Opportunity Rover at Endeavour Crater, Meridiani Planum
L. Crumpler, MER Science Team & New Mexico Museum of Natural History & Science
The Mars Exploration Rover Opportunity is still exploring Mars.
Sol 3111- October 23, 2012
We on the MER Opportunity science team are currently doing an “outcrop walk” with Opportunity on the slopes of Cape York, a small residual part of the rim on the 20+ km diameter Endeavour crater, Mars. This part of Cape York where we are currently exploring is where we have evidence for ancient clays and we would like to examine them. On Earth, when mapping the geology of an area, a geologist often walks around getting a general feel for what outcrops are present and what particular outcrops will be the best for sampling or for testing a particular hypothesis. So with Opportunity we are doing a loop and then deciding where to spend our time analyzing an outcrop. As we drive along with Opportunity, I map out the geologic contacts and try to match them up with a “base map” that consists of an MRO/HiRISE image of Cape York, a .
I suggested a loop that took us through all of the important areas of outcrop that are detectable from MRO/HiRISE images, going up hill along the ridge vrest and then back down nd eventually returning to the starting point. Along this traverse we are acquiring 360 panoramas with the Navcams as well as detailed color Pancam images of possible targets of interest. Some interesting and strange rocks and alterations have been detected, and we may check them out later. But first we need to complete the loop. We are about half-way through the lop. Who knows what we will see on the next drive. It’s all unexplored terrain. Nobody has ever been here before!
Below are some images to show where we are and what we are doing.
Opportunity is currently exploring a small ridge, Cape York, that is a remnant of a large impact crater dating from early Mars geologic history. The crater (Endeavour crater) is about the size of New Mexico's Valles caldera
We have been exploring along the margins of Cape York since sol 2681. This map shows the traverse north and around the north top of Cape York, and the drive south along the east side. About half-way down the side we directed Opportunity into the interior in search of outcrops of clay minerals.
As we traverse the surface and visit outcrops, I keep a running record of the observations in the form of a geologic map. This is the first geologic mapping on the surface of another planet based on actual on-the-site field observations! This is not a photogeologic map. It is a field-based map.
Each stop is enclosed by a vertically projected version of the 360 Navcam panoramas (grayish blocthes). These provide details at cm-scale to better understand the regional outcrops mapped in the MRO/HiRISE image used a s a base map.
Below is a small south-looking segment of the 360 degree Navcam panorama acquired at the end of the drive on Oct 23 (sol 3110).
Opportunity Rover: Finished Outcrop Walk, Starting Detailed Examination of Outcrops, Looking for Clays
In my last report above, Opportunity had completed about half (station 7) of the planned 14 stations on a looping drive and survey of outcrops here at an important site here on Matijevic Hill.. With the drive to station 14 on sol 3133, we completed that big loop drive around the outcrops (Matejevic Hill is the name we have given to a part of the larger hill “Cape York”, which is an eroded and isolated remnant of the 20+-km diameter Endeavour crater, a piece of the ancient Martian crustal rocks.)
Here at station 14 we have decided to do a detailed investigation of an outcrop that is well exposed and lies within an area where there is orbital remote-sensing evidence for clay minerals. These particular rocks are interesting in that they contain a lot of thin veins and alteration zones along joints (cracks) in the outcrops. Also, as you can see in the images below, up close with the Microscopic Imager the face of the outcrop appears coated with a varnish-like layer, and this in turn is part of a slab-like alteration rind that gives the outcrop the characteristic scaly appearance. Below that is the relatively light-toned outcrop rock. The rock itself is very fine-grained, dust-sized material with few clasts, unlike the chunkier stuff on the crest of the hill. It may be part of the impactites here on the rim of Endeavour or it could be the pre-impact country rock. Whatever it is, it is old, altered, and common on the lower flanks of the hill. More important it may be altered to clay.
Next we will likely drive to the outcrop just a few meters west and try to make sense of the contact between the two rock types that can be seen there. After that Opportunity will drive north along the loop to station 2 through 4 where we hope to determine the stratigraphic context of these rocks with respect to he chunkier impactites we saw mostly uphill.
Overview of the traverse on Cape York showing the location of the current detailed traverse loop.
The traverse loop thus far. This image is an MRO-HiRISE image onto which I have mapped the geologic units that Opportunity has encountered and we have identified along its traverse. The geology is determined and mapped much like you would do in the field here in the field in New Mexico. This map, a part of the one above, represents one of the first field geologic maps done on the surface of Mars. Contour intervals are 1 m.
The image collection here gives you an idea of the types of data we acquired at each stop. This shows part of the 360 degree Navcam panorama and a couple of the high-resolution, focused Pancam color frames. Note that the outcrops here contain a lot of clasts or chunks. These have been seen elsewhere on Cape York and look like impact breccias.
Below are a few views from the current station as of this sol, Station 14, and some of the work we are doing on this outcrop.
This Navcam view looking north and along the east side of the hill shows the bright outcrop near station where we started the loop several weeks ago. On the right horizon is the far rim of Endeavour crater which is about 22 km away.
This Navcam view looks south and shows our tracks leading from Station 13. In the distant is a mountain we have named “Cape Tribulation” that is several miles away. It is a steeper and bigger version part of the west rim south of Endeavour Crater south of Cape York . This is the currently preferred goal for the end of the cming Martian summer. But we need to finish our work here on Cape York first.
This Navcam view looks west and up hill shows the outcrop in front of us.
This is from the front Hazcam and shows the RAT poised above the outcrop after a successful grind.
Before the grind, we did a RAT “brush” which reveals the “varnish fairly well. The images on the left are from the Microscopic Imager and the color image on the right is from the Pancam.
The same sequence of images showing the outcrop target after the RAT grind.
Mars Exploration Rover Press Conference at the Fall AGU Meeting, Decemebr 5:
(Wait for static to end and the press conference will start.)
An attempt to bump left and get a small bright vein into the IDD work volume failed to get the target in the work plane. The Rover Planners figure that it could take several attempts to acquire such a tiny target. So the Science Team decided on Wednesday to bag it and move on to bigger fish. The decision was made to drive to the outcrop to the immediate west "Copper Cliff". On FRiday we will then plan how to proceed. If lucky we will have one f the lithologies within the work volume. If not, we will determine what we want to examine and bump to it for planning on Monday.
Sol 3153 - December 7, 2012
So we bumped towards the big outcrop ("Copper Cliff"). In the next plan we will center the rover work volume on a target that we have selected.
We finished up with examination of the big outcrop ("Copper Cliff") and moved to the next target over the weekend.
With that drive Opportunity completed the loop around Matijevic Hill and is now back where it started on the big loop to examine the outcrops. It is now resuming detailed observations of the outcrop Whitewater Lake. The object of the return to Whitewater Lake are small bright veins throughout the outcrop there. The hope is that we will be able to get an assessment of the composition of the veins. Once we are done here we plan to try to find a good outcrop where we can determine the composition of the the so-called “newberries” or “not-blueberries” that were identified back around sol 3060. We did see some dispersed newberries in the last outcrop where there was a distinct contact between Whitewater Lake and overlying impact breccias. The newberries could be related to the impact process and might e similar to the lapilli or volcanic “hailstones” common in certain volcanic eruptions.
Below is a part of the Navcam panorama at the end of the drive this week. The bright squarish outcrop is the target outcrop, Whitewater Lake. The rim of endeavour crater continues to the south.
Here is a look at the status of the of the traverse around the hill as recorded in my geologic mapping based on rover observations.
Another New Mexico name gets used for a Mars outcrop target.
The drive to the current target went well. But Opportunity will need to do some “adjustment” bumps in order to put the target in the work volume of the IDD. Because the IDD has a bad shoulder joint, Opportunity can only operate the arm in a single plane, more or less. So the part of any outcrop target that we would like to examine has to be pretty much in that plane and reachable. So careful positioning is necessary with particularly small targets like the one we are attempting to analyze.
This target, which could be an important one here as we search for characteristics in these outcrops that are consistent with clay mineralogy. Since we are trying to examine one of the many small veins that occur within the outcrops here, we will use a name from a gold mine or mining area here on Earth. I suggested that we use the Ortiz gold mining district for naming this target.
The Ortiz Mountains were the site of the first gold rush in the western U.S., pre—dating the CA rush by seven years, at least; the source of most of the gold that was used to pay the traders from the Santa Fe trail; and in many ways more significant to western history than the CA gold rush and other probably more widely known areas of mineral exploration.
Here is the target as seen in stand-off images from this latest drive. We will drive (“bump”) again this sol in order to reach Ortiz. The next downlink on Friday will tell the tale.
We completed the bump and may have the target in the work volume....we think.
But we can't be sure until we do a big MI mosaic of this location. So we are doing that this weekend.
It will be a nice mosaic and we will use it tactically on Monday to determie if we have a good location for RAT brushing and APXS.
Here is my latest map of the rover position with respect to overhead projections of the Navcams.
Pancam looking down on the target "Ortiz" that we are analyzing on this outcrop. Note all the small veins
Below is a view of the Ortiz Mountains, New Mexico, located between Albuquerque and Santa Fe, which is the source of our naming theme here on this outcrop.
The Ortiz Muntains are a mid-Cenozoic monzonite intrusion complex that was heavily mineralized.
The Ortiz Mountains were the site of some of the earliest gold mining operations in the U.S., including the first large gold rush in the western U.S.
This weekend we will move to another outcrop to the north and ry to get a handle on the strange newberries. And maybe take a look at the alteration zones that have caused the boxwork type structures common to these outcrops.
While we wait to get there, take a look at the chart below. If all goes well, Opportunity will break the interplanetary rover distance record by next August.
We have been seeing lots of small light-colored veins crossing through the outcrops here on Matijevic Hill, and we have tried to get a handle on the composition of these veins by doing multiple offsets with the APXS. It appears that the small veins are calcium sulfate, as best we can determine. In other words, they are probably gypsum like the large veins that we saw around the margins of Cape York. Here are exmples of some of theseback in the Ortiz outcrop. They are tiny, measuring at a millimeter or two in width. But they are everywhere.
Oddly enough, Curiosity has just encountered a similar sort of veins in the outcrops where it is sitting at gale Crater.
We moved north to an outcrop we called “Flack Lake” recently and did a quick look at the rocks with the MI and APXS. The target name was “Fullerton”. Here is a MI mosaic of Fullerton, an area on the outcrop a little under 3 inches across that we brushed with the RAT. The image from the MI has been co-registered with a color Pancam image in order to bring out the color.
It looks like the "newberries" are part of the Whitewater Lake outcrop, not just loose spherules sitting on top of the outcrop surface. So the contact between Whitewater lake and the impact breccias farther upslope (we think) that we have been calling "Shoemaker Formation", may be transitional. The iron content of the rock here based on the APXS results is not sufficient for these to be hematite concretions (“blueberries”). These are something different.
With that question examined, the next question on our list is the location of the contact between the rocks low on the hillside, which tend to look like Whitewater Lake, and the more impactite-like rocks we saw up on the ridge crest. So we have driven upslope around sol 3212 to see if we can find the contact between the rocks containing newberries and the rocks that are more like impact breccias in appearance.
Here is my geologic map of our current location. We think the brown unit labeled “S” is on top of the pink unit labeled “W”. But we need to confirm that. So in the next drive we will go up slope to the outcrops on the crest of the hill.Remember that we have previously driven a loop around the outcrops to see what is here. And now we are going back at looking at the especially interesting and informative outcrops, just like the way we would do it in the field here in New Mexico.
Here is a zoomed-in look at the local terrain showing where Opportunity is and where it will drive in the next sol. These are Navcam frames that have been re-projected to an overhead view. The red tracks are the current drives, and the yellow tracks are from the prpevious drive trhough this area last month.
If we are lucky, we will be driving downslope and preparing to finish up our outcrop investigations here on Matijevic Hill within the next seven days or so.
We sent Opportunity a few meters uphill looking for the contact and are trying to get a quick composoition and microscopic image on the outcrop. It looks like the Shoemaker Formation (impact breccia). If the rock has round spherules, it would be unlike the breccias we saw elsewhere along the ridge crest.
Here is latest map that I prpepared after the sol 3219 drive. The base image for this map is a mosaic of the local Navcam panoramas reprojected in vertical presepctive.
Sol 3219-3226 - Opportunity completed the observations of the outcrop noted in the last report above and has now moved back down slope. We acquired a good Pancam color image of the outcrop before Opportunity moved. It appears to be a breccia, as we expected. But we wanted to see if we could find the contact between this breccia and the relatively smooth and featureless outcrops that we are seeing down slope. The breccia is no surprise since, in this setting which is on the rim of an impact crater (the size of the Valles Caldera), this outcrop probably consists of broken rocks from the crater ejecta. The target name is “Maley.”
Sol 3227 to tosol* (3236) - After Opportunity finished analyzing this outcrop we began the process of leaving Cape York/Matijevic Hill by heading east, down slope. We wanted to visit a peculiar area where the outcrops appear to be a “boxwork” of vein-like areas enclosing what appear to be relatively unaffected core stones. This sort of outcrop is common in tropical weathered rocks on Earth. But on Mars, well it may indicate that there was a lot of water somewhere along the line! But we want to get a good handle of these features, including any obvious alteration, before we depart. These types of slugging observations are how science build up a story about what happened in the geological past. We are putting together a picture of a Mars that you may not recognize.
After we finish up on this target over the next sol, we will start driving south. But we will do one final stop at the strange outcrop of “newberries”. We have one more trick to try on these to see if we can figure out the composition. That activity will occupy the next few sols.
Target name at the current locatio of Opportuity is “Lihir.” You can see that the boxwork structure is somewhat lighter colored.
Road trip! Then, hopefully in the coming week, we will start the major 2 km-plus journey south. We need to be at Solander Point, the next big mountain on the rim of Endeavour crater, by August 1 inorder to set up for winter.
Here what the nominal traverse plan looks like. This will change but not by much. Opportunity will be exposed to the mercy of storms and unforeseen events as it makes this dangerous crossing. And there are almost no “bail-out” points along the way. Stay tuned.
Flash memory or computer problems oddly occurred on both Curiosity and Opportunity around feb 27. One possibiliy is that a large solar flare resulted in radiation at Mars sufficient to temporarily corrupt the memory on both rovers. Mars is currently a few weeks away from solar conjunction, so big flare could have happened on the other side of the Sun.
Opportunity has ecovered from the event and is GO for planning a re-do of observations. We hope to have the data by Tuesday morning in time to plan a drive south.
Opportunity is doing one last "hurrah" here at Cape York on a particularly interesting outcrop with a composition and structure unlike anything encountered before. We were about to start driving southward after the last stop, but the results came down from this strange outcrop. And unlike our tendency to avoid driving back to a previous spot, we decided we had to get more information on this rock unit. Then we have got to start driving south towards the next mountain.
So this will mean staying here through the communication blackout that happens during solar conjunction which is coming up on April 7 and lasts until April 26. This is the period when Mars moves behind the Sun for a few weeks and communication is cut off. Actually communication is only cut off after Mars passes behind the Sun, but the deep space communications people say the communication gets dicey as the edge of the Sun gets close, and we like to avoid commands getting scrambled.
Below are some images from the current location. The outcrop has a "boxwork" structure that on Earth would be the result of deep weathering of bedrock, such as occurs in tropical environments. The boxwork has a composition unlike the host rock. So the stop here is to get some more information about how it formed. Any way you slice it though, it means Mars was really wet when this happened.
Sol 3262 Navcam mosaic looking in the direction that Opportunity will be driving immediately after solar conjunction. You can see the mountain range to the south where we need to be by August 1. The dot at azimuth of 180 near the image center shows the direction that we will drive. Note all the tracks all over the place. We have been busy on this hill looking at things and trying to do a good job at it while we are doing it.
This is a view from the rover's front Hazcam of the outcrop. The view is north across the west flank of Cape York. So the mountains in the distance on the right are the northern rim of the 22 km-diameter Endeavour crater.
This is what the outcrop looks like from the Pancam. You can see the raised rectangular area and how it tends to encircle quasi-orthogonal cores of unaffected rock.
And this is a frame from the Microscopic Imager of the target. The image is about 3 cm across.
• Opportunity breaks off-Earth driving distance record set by Apollo 17
Opportunity has finally completed the detailed survey of the outcrops on the Cape York segment of the rim of the 22-km diameter Endeavour crater. It has been sitting at a large vein-like feature cutting across the outcrops here since early May. Half of that time occurred during solar conjunction when all rover actities were reduced since Mars was on the other side of the Sun and communication was not possible. This turns out to be a strange rock type. Stay tuned for results.
On Wednesday (May 15) of this week we began driving away and have made good progress. In fact we have driven three sols now and gone close to a 230 meters. On Tursday, May 16, Opportunity exceeded the distance record (35.74 km) set by the Apollo 17 astronautrs Cernan and Schmidt. Opportunity is now only 1.24 km from the all time record set by Lunakhod 2 in 1973 (37 km). That will happen in the next couple of months as we drive steadily to the south.
Here is my map of the current status of Opportunity's traverse. Count three red dotrs back and you can see where we were sitting for the observations at the last outcop "Esperance". The red line shows the beginning of the nxt drive that we hope to do first thing next week.
This is a view in the front hazcam looking back at the end of the last drive on the early hours of May 17.
And here is a Navcam frame looking south in the drive direction. In a couple of more drives we will be off this "beach" and back into the plains. The next "landfall" will be that small bump in the distance on the horizon. Stay tuned.
This is a view of the outcrop target "Esperance" in which I have mapped out the principal features. Note the large whitish zone between blocks of rock making up the outcrop. We used the RAT to grind into this and analyzed it with the APXS. The small gray square is about 3 cm on a side and is the Microcropic Imager Mosaic we did after the grind. All sorts of interesting results that will be reported in the next few weeks.