Tag Archives: Gale Crater

Mars rover update: February 14, 2017


Ireson Hill, Sol 1604

Dune fields

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Taking a close look at rock

Since my last update in January, Curiosity done more or less what I predicted. It headed southwest through the dune area and then made a side trip to the small mesa there, dubbed Ireson Hill by the Curiosity science team and shown on the right. They then made an additional side trip past the hill to get a close look a the large sandy dune field beyond, also shown on the right. After getting some nice closeups as well as scooping up some sand for observation, they have now gone back to Ireson Hill to get another close look at the dark rocks that have rolled off the top of the hill and are now in reach at its base. The image on the left shows the arm positioned above one of those rocks.

The drill remains out of commission, with no word when they will try using it again. In addition, there had been a problem with the ChemCam laser that does spectroscopic analysis, but as of this week it is back in action, and is being used to analysis the small rock above.

Below is an overview of their route so far as well as my annotations on where I think they will be heading in the future.
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Mars rover update: January 18, 2017


Curiosity's location, Sol 1582

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

In the past month, since my last rover update on December 22, 2016, Curiosity has begun moving again, carefully picking its way through the dune-filled flats in the foothills at the base of Mount Sharp. The route taken, shown on the image on the right, corresponds to the easternmost of the possible routes I noted in my November 14, 2016 update. This route is also the most direct route, which I think is smart considering that the rover’s life on Mars certainly uncertain and the higher they can climb the more geological information they will get.

I have also annotated the likely route into the near future, including a possible side trip to the base of the mesa up ahead. It appears to me that they are now a little more than halfway through the flats, with Mt. Sharp directly ahead, as shown by the panorama below, taken near the end of December. The goal is a canyon just out of view to the right of this panorama.

Looking at Mount Sharp

The flats the rover is presently traversing, and visible in the foreground of the panorama above, is strewn with dark sand that often piled into large sand dunes. Where the ground is exposed, it is made up of a scattering of pavement-like rocks. As noted in a press release yesterday, many of these flat rocks have polygonal cracks and boxwork similar to that seen in dried mud here on Earth, suggesting that this area was once wet and then dried. This geology helps confirm the theory of planetary scientists that Gale Crater was once filled with water that slowly evaporated away. As the rover climbs, it leaves the lakebed and begins to move through the lake’s various shores, each one older than the last.


For the overall context of Opportunity’s travels at Endeavour Crater, see Opportunity’s future travels on Mars.
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Curiosity spots cracks formed from drying mud

mud cracks on Mars?

As Curiosity moves across the dust-shrewn dune-filled flats at the base of Mt. Sharp it has recently taken images of surface rocks that have cracks resembling those found from drying mud.

Scientists used NASA’s Curiosity Mars rover in recent weeks to examine slabs of rock cross-hatched with shallow ridges that likely originated as cracks in drying mud. “Mud cracks are the most likely scenario here,” said Curiosity science team member Nathan Stein. He is a graduate student at Caltech in Pasadena, California, who led the investigation of a site called “Old Soaker,” on lower Mount Sharp, Mars.

If this interpretation holds up, these would be the first mud cracks — technically called desiccation cracks — confirmed by the Curiosity mission. They would be evidence that the ancient era when these sediments were deposited included some drying after wetter conditions. Curiosity has found evidence of ancient lakes in older, lower-lying rock layers and also in younger mudstone that is above Old Soaker.

The rover is no longer on the floor the crater, but in the foothills at the base of Mt. Sharp. Thus, what we are likely looking at is evidence of the slow disappearance of the giant lake that scientists think once filled Gale Crater. These mud cracks suggest that the rover is now moving up out of the lake and through its margins.

I plan to do a rover update for both Curiosity and Opportunity tomorrow, so stay tuned.

Curiosity looks at Mount Sharp

Looking at Mount Sharp

Cool image time! During the ten day holiday period, during which the Curiosity science and engineering teams generally got a break, they programmed the rover to take a variety of observations over the entire period. Some of those observations included repeated snapshots of the view ahead, using the rover’s navigation camera. The image above, reduced slightly from the full resolution image to show here, is one example of that view.

You can see the dark sandy dune region in the foreground, and the increasing steepness of the slope in the background. What I find most interesting are what look like canyon washes flowing downhill on the right, in what appear to be diagonally parallel cuts. That they do not flow directly downhill suggest to me that they were not created by water flow but by wind erosion, though it is possible that the geology of different bedding plains could have forced the flows in a diagonal direction down the slope. If wind erosion is the cause, however, it suggests a process that took a very long time to occur, as the atmosphere of Mars is so thin.

The route the rover will take is through a much larger canyon slightly off camera to the right. While the slope up the mountain on the left of the image appears to be an easier route, the geology there is not as interesting. Note also that we are not looking at the peak of Mount Sharp, which is much farther south and far higher.

Mars rover update: November 14, 2016


Curiosity looking south, Sol 1516

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Since my last update on November 3rd, Curiosity has reached the region of sand dunes and has started to pick its way through it. The panorama above was created using images from the rover’s left navigation camera, taken on Sol 1516. It looks south, with Mount Sharp rising on the left.

That same day Curiosity also used its mast camera to zoom in on the canyon gap in the center of the panorama. The first image below is the wider mast camera shot, with the an outline showing the even closer zoom-in below that.
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Mars rover update: November 3, 2016


Post updated: See last paragraph in Curiosity section.

Curiosity location 1507

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

After spending almost a month on the flats south of Murray Buttes, during which the rover drilled another hole, in the past week Curiosity has finally resumed its journey south toward the slopes of Mount Sharp and the sand dune area that it must cross to get there.

Unfortunately, NASA has decided to change how it shows the rover’s progress, and these changes seem to me to be a clever and careful effort to make it more difficult for the public to make educated guesses about where the rover might be heading in the very near future. The image to the right is the cropped inset showing the rover’s recent travels that is part of a new a larger image that puts this inset in the context of the rover’s entire journey. This has replaced the wider orbital mosaic that they used to provide (see for example my September 27, 2016 rover update) that gave a very good view of the entire terrain surrounding the rover from which a reasonable estimate of its future path could be guessed.
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Mars rover update: October 6, 2016


Post updated. See last paragraph of Curiosity section.

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

Curiosity looking west, Sol 1475

Having moved south from Murray Buttes, the Curiosity science team has decided [see Sol 1473] that they will veer the rover to the southwest a bit, partly to check out some interesting features but also I think as part of a long term plan to find the best route through an area of sand dunes that blocks their path to the more interesting landscape at the base of Mount Sharp. The panorama above, created by me from images taken by the rover’s mast camera on Sol 1475, was taken to scope out this route, and is indicated below the fold in the overview released earlier this week by the rover science team and annotated by me to indicate the direction of this panorama as well as the rover’s present location. (Be sure to click on the panorama above to see it at full resolution.)
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Mars rover update: September 20, 2016

Opportunity comes first this time because it actually is more interesting.


For the overall context of Opportunity’s travels at Endeavour Crater, see this post, Opportunity’s future travels on Mars.

Having several choices on where to head, the Opportunity science team this week chose took what looks like the most daring route, heading almost due east towards the floor of Endeavour Crater. In fact, a review of their route and the images that the rover continues to take suggests that the panorama I created last week looked almost due east, not to the southeast as I had guessed. I have amended the most recent overhead traverse image, cropped and reduced below, to show what I now think that panorama was showing.
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A Mars Rover Update

I have decided to continue my Mars rover updates, and make them a regular mid-week feature here on Behind the Black. This is the first.


For the overall context of Curiosity’s travels, see this post, Pinpointing Curiosity’s location in Gale Crater.

Since my last updates here and here, Curiosity has moved south through the gap between buttes to exit the Murray Butte area. The initial slopes of Mount Sharp lie ahead, an open road with no apparent rough terrain to slow travel.

Doing science however does slow travel, and for good reason. Once through the gap the science team decided to swung the rover west and up against the base of the gap’s western butte, rather than immediately head south to climb the mountain. The Mars Reconnaissance Orbiter image below, cropped and reduced, illustrates this path.
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NASA touts Curiosity images of Murray Buttes

A NASA press release on Friday highlighted some of the fantastic images of Murray Buttes that Curiosity has been taking for the past month and that have already been highlighted here several times at Behind the Black during the past several weeks.

Take a look. The images they show are not the same ones I have already posted, and are worth seeing.

New evidence suggest lake once existed in Gale Crater

Scientists have concluded that mineral veins seen by Curiosity in Gale Crater were created when a lake existed there.

The study suggests that the veins formed as the sediments from the ancient lake were buried, heated to about 50 degrees Celsius and corroded. Professor John Bridges from the University of Leicester Department of Physics and Astronomy said: “The taste of this Martian groundwater would be rather unpleasant, with about 20 times the content of sulphate and sodium than bottled mineral water for instance!”

Route to Balanced Rock

Route to Balanced Rock on Mars

The image above is a panorama I have created from the raw images taken by Curiosity’s left navigation camera today, using this image for the left half and this image for the right half. They show the terrain in front of the rover, including the balanced rock on the horizon, indicated by the arrow.

I have no idea what route the science team plans, but looking at all of the images, as well as their desire to get a closer look at the rock, I suspect they will head up to the left on the smoother ground, aiming almost directly at the balanced rock. I also suspect that they will eventually veer right before getting to the rock, since the rover can’t go over the rough terrain in that area. Stay tuned to find out.

Curiosity heads south

After four years of southwest travel to skirt a large dune field at the base of Mount Sharp, Curiosity has finally turned due south to aim directly up the mountain.

“Now that we’ve skirted our way around the dunes and crossed the plateau, we’ve turned south to climb the mountain head-on,” said Curiosity Project Scientist Ashwin Vasavada, of NASA’s Jet Propulsion Laboratory, Pasadena, California. “Since landing, we’ve been aiming for this gap in the terrain and this left turn. It’s a great moment for the mission.”

Pinpointing Curiosity’s location in Gale Crater

Curiosity's traverse

The Curiosity science team recently released a new Mars Reconnaissance Orbiter image, showing Curiosity’s overall route since its landing on Mars in August 2012. I have posted a reduced version on the right.

Similarly, on the Curiosity website you can view this more detailed map of its traverse route. This map is updated regularly as Curiosity continues its climb up Mount Sharp.

Neither of these maps is to me very satisfying or useful, however. Neither shows the overall location of Curiosity within Gale Crater. Nor do they give one a sense of how far it is has come on its climb up the mountain. In fact, it is very unclear how close the rover actually is to the peak from either image.

Thus, I decided to do a little research to get some better context of Curiosity’s position and its overall journey.
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Getting higher on Mount Sharp

Looking across Gale Crater

Cool image time! The above image, cropped and reduced slightly for presentation here, was taken by one of Curiosity’s navigation cameras on March 2. Though the science team has not captioned it, I think it is looking down from the heights that Curiosity has climbed and across the plains of Gale Crater to its rim in the far distance. The image itself appears to have been taken after the rover spent several days climbing up to what they have dubbed Naukluft Plateau.

Be sure to check out the full resolution image that can be found here.

Curiosity heads for the dunes

Bagnold Dunes

The Curiosity science team has decided to send the rover towards some large active dunes, visible in its journey ahead up Mt. Sharp.

On its way to higher layers of the mountain where it is investigating how Mars’ environment changed billions of years ago, NASA’s Curiosity Mars rover will take advantage of a chance to study some modern Martian activity at mobile sand dunes.

In the next few days, the rover will get its first close-up look at these dark dunes, called the “Bagnold Dunes,” which skirt the northwestern flank of Mount Sharp. No Mars rover has previously visited a sand dune, as opposed to smaller sand ripples or drifts. One dune Curiosity will investigate is as tall as a two-story building and as broad as a football field. The Bagnold Dunes are active: Images from orbit indicate some of them are migrating as much as about 3 feet (1 meter) per Earth year. No active dunes have been visited anywhere in the solar system besides Earth.

In the image on the right the target dune is in the center beyond the dark ridge line in the foreground. It looks kind of like a pointed mesa. the dark sandy area on the center right just below the dark ridge line in the center of the image. (Newer images released today gave me a more correct idea of the dunes as shown in this image.) Click here to see the full image. The rover is presently about 200 yards from the first dune, and should reach it in the next few days.

More confirmation from Curiosity of past lakes in Gale Crater

New data from Curiosity has now provided further confirmation that the deeper sedimentary layers seen in Gale Crater were likely formed far in the past by flowing water.

“Paradoxically, where there is a mountain today there was once a basin, and it was sometimes filled with water,” said John Grotzinger, the former project scientist for Mars Science Laboratory at the California Institute of Technology in Pasadena, and lead author of the new report. “We see evidence of about 250 feet (75 meters) of sedimentary fill, and based on mapping data from NASA’s Mars Reconnaissance Orbiter and images from Curiosity’s camera, it appears that the water-transported sedimentary deposition could have extended at least 500 to 650 feet (150 to 200) meters above the crater floor.”

Furthermore, the total thickness of sedimentary deposits in Gale Crater that indicate interaction with water could extend higher still, perhaps up to one-half mile (800 meters) above the crater floor.

Above 800 meters, Mount Sharp shows no evidence of hydrated strata, and that is the bulk of what forms Mount Sharp. Grotzinger suggests that perhaps this later segment of the crater’s history may have been dominated by dry, wind-driven deposits, as was once imagined for the lower part explored by Curiosity.

This was always the reason to go and climb Mount Sharp. As Curiosity heads uphill it begins to map out the geological history of Mars, first as a wet place with liquid water, then as a dry place in which the water is gone.

Curiosity’s future path

Looking up Mt Sharp

Cool image time! The Curiosity science team has produced another panorama of Mount Sharp and the regions that the rover will soon traverse.

This composite image looking toward the higher regions of Mount Sharp was taken on September 9, 2015, by NASA’s Curiosity rover. In the foreground — about 2 miles (3 kilometers) from the rover — is a long ridge teeming with hematite, an iron oxide. Just beyond is an undulating plain rich in clay minerals. And just beyond that are a multitude of rounded buttes, all high in sulfate minerals. The changing mineralogy in these layers of Mount Sharp suggests a changing environment in early Mars, though all involve exposure to water billions of years ago. The Curiosity team hopes to be able to explore these diverse areas in the months and years ahead. Further back in the image are striking, light-toned cliffs in rock that may have formed in drier times and now is heavily eroded by winds.

They have adjusted the colors, adding blue, so that things look as they would on Earth, in order to help the geologists understand what they are looking at.

Be sure and click on the link. The full resolution image is quite amazing. Like mountains on Earth, from a distance things look a lot simpler than they do once you get there. The slopes of Mount Sharp are complex and rugged, and will be a big challenge for Curiosity to traverse.

Moreover, this rough terrain illustrates that the Martian surface has, like Earth, been significantly shaped by erosion. The surface we see here is not the surface produced by the impact that produced the crater. It has been reshaped and eroded over many eons by many later processes, including wind and water.

Petrified sand dunes on Mars

Petrified sand dunes on Mars

Cool image time! A panorama produced from images taken by Curiosity’s Mast camera has revealed the remains of ancient sand dunes, cemented into sandstone and now eroding.

This sandstone outcrop — part of a geological layer that Curiosity’s science team calls the Stimson unit — has a structure called crossbedding on a large scale that the team has interpreted as deposits of sand dunes formed by wind. Similar-looking petrified sand dunes are common in the U.S. Southwest. Geometry and orientation of the crossbedding give information about the directions of the winds that produced the dunes.

The Stimson unit overlies a layer of mudstone that was deposited in a lake environment. Curiosity has been examining successively higher and younger layers of Mount Sharp, starting with the mudstone at the mountain’s base, for evidence about changes in the area’s ancient environment.

The image above is cropped and reduced in resolution. Be sure to look at the original.

This report also suggests that Curiosity is definitely moving up the geological layers on Mount Sharp. With each layer, we learn a little bit more about the complex geological history of Gale Crater.

Curiosity looks ahead at its future travels

The future terrain at Mt Sharp

Cool image time! The above image is a cropped version of a full resolution image taken by Curiosity of the terrain the rover will be traveling in the coming years.

I have also enhanced the contrast slightly to bring out the details. The terrain is rugged and very diverse, from rounded buttes to rocky outcrops.

Gravel and sand ripples fill the foreground [not shown in my cropped version above], typical of terrains that Curiosity traversed to reach Mount Sharp from its landing site. Outcrops in the midfield are of two types: dust-covered, smooth bedrock that forms the base of the mountain, and sandstone ridges that shed boulders as they erode. Rounded buttes in the distance contain sulfate minerals, perhaps indicating a change in the availability of water when they formed. Some of the layering patterns on higher levels of Mount Sharp in the background are tilted at different angles than others, evidence of complicated relationships still to be deciphered.

Traversing this rugged terrain will be a challenge but it is necessary to obtain data that will help decipher its origins. The immediate goal will be to reach the light brown terrain in the distance. In the full image, that region gently slopes upward to the left to the mountain summit, providing a route to the rover’s eventual goal.

Sunset on Mars

sunset on Mars

Cool image time! The image above is not a sunset over the Blue Ridge Mountains of Tennessee. It is a beautiful blue sunset on Mars, taken by Curiosity from Gale Crater.

The image is the first sunset imaged by Curiosity in color, and is calibrated to match what the human eye would see.

Meanwhile, the rover’s journey continues, with a slight detour to check out an interesting hillside.

More evidence found for liquid water on Mars

A new study suggests that a liquid but very salty water does appear on Mars, during the night in the winter and spring months.

The team used Curiosity’s weather-monitoring equipment to look for those conditions and found that they occur every day in months throughout winter and spring. They suggest that overnight and before sunrise, some of the frost that forms on the planet’s surface interacts with the strong salts and turns liquid, seeping into the soil. This lines up with previous studies, which have detected geographic features that suggest flowing water.

The results come from the Gale Crater, which is itself too cold to support microbial life — even with liquid water present. But the study authors believe this phenomenon could occur anywhere on the planet, and may actually be more common in areas closer to the polar regions. Still, Mars is a pretty desolate place, and the amount of water we’re talking about is minimal at best. “There’s so little water that you can’t even see it visibly,” Morten Bo Madsen said.

Curiosity finds nitrates on Martian surface

Using data from Curiosity scientists have for the first time identified nitrates, also called fixed nitrogen, on the Martian surface.

There is no evidence to suggest that the fixed nitrogen molecules found by the team were created by life. The surface of Mars is inhospitable for known forms of life. Instead, the team thinks the nitrates are ancient, and likely came from non-biological processes like meteorite impacts and lightning in Mars’ distant past.

Features resembling dry riverbeds and the discovery of minerals that form only in the presence of liquid water suggest that Mars was more hospitable in the remote past. The Curiosity team has found evidence that other ingredients needed for life, such as liquid water and organic matter, were present on Mars at the Curiosity site in Gale Crater billions of years ago.

The data also suggests that these nitrates are widespread on the Martian surface.

The most important aspect of this discovery to me is not so much that it suggests the faint possibility of past life on Mars but that it makes Mars a more hospitable place for life in the future. Nitrates are essentially fertilizer, and for Mars to have this material in the soil already means it will be easier to figure out how to grow crops there.

Curiosity confirms that Gale Crater was once a water filled lake.

New geological data from Curiosity suggests that the interior of Gale Crater was shaped by sediments placed there by the rise and fall of a lake over millions of years.

The data also confirms that conditions on Mars were good enough for liquid water to be maintained on the surface for long periods of time. The problem is that scientists still do not understand how Mars could have maintained such kind of atmosphere and environmental conditions, based on its location and size.

A geological score for Curiosity!

Spectroscopy from Curiosity’s most recent drilling has been found to match and thus confirm the spectroscopy of the same spot taken years ago from orbit.

In observations reported in 2010, before selection of Curiosity’s landing site, a mineral-mapping instrument on NASA’s Mars Reconnaissance Orbiter provided evidence of hematite in the geological unit that includes the Pahrump Hills outcrop. The landing site is inside Gale Crater, an impact basin about 96 miles (154 kilometers) in diameter with the layered Mount Sharp rising about three miles (five kilometers) high in the center.

“We’ve reached the part of the crater where we have the mineralogical information that was important in selection of Gale Crater as the landing site,” said Ralph Milliken of Brown University, Providence, Rhode Island. He is a member of Curiosity’s science team and was lead author of that 2010 report in Geophysical Research Letters identifying minerals based on observations of lower Mount Sharp by the orbiter’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). “We’re now on a path where the orbital data can help us predict what minerals we’ll find and make good choices about where to drill. Analyses like these will help us place rover-scale observations into the broader geologic history of Gale that we see from orbital data.”

This is a significant finding. Not only does this data now prove that the orbital data is correct, it demonstrates that scientists can now use that orbital data to direct Curiosity to even more interesting geological surface features. In fact, this ground-based data will help them calibrate all their orbital data more precisely, thus making our geological knowledge of Mars more accurate and reliable.

Curiosity to begin climbing

Scientists have decided to begin Curiosity’s climb of Mount Sharp immediately rather than continue a planned traverse along the base of the mountain prior to heading uphill.

Curiosity’s trek up the mountain will begin with an examination of the mountain’s lower slopes. The rover is starting this process at an entry point near an outcrop called Pahrump Hills, rather than continuing on to the previously-planned, further entry point known as Murray Buttes. Both entry points lay along a boundary where the southern base layer of the mountain meets crater-floor deposits washed down from the crater’s northern rim.

The issues with Curiosity’s wheels also played a part in this decision.

Curiosity cancels drilling and moves on

Adventures on Mars: After finding that a candidate rock for drilling was not stable enough, Curiosity engineers have canceled the drilling and instead decided to continue the rover’s journey towards Mount Sharp, having chosen a new route that bypasses Hidden Valley, which was found to be too slippery.

Curiosity retreats from Hidden Valley

Finding its sandy floor slipperier than expected, engineers have backed Curiosity out of Hidden Valley to drill some holes while they reassess the rover’s route.

The rover’s wheels slipped more in Hidden Valley’s sand than the team had expected based on experience with one of the mission’s test rovers driven on sand dunes in California. The valley is about the length of a football field and does not offer any navigable exits other than at the northeastern and southwestern ends. “We need to gain a better understanding of the interaction between the wheels and Martian sand ripples, and Hidden Valley is not a good location for experimenting,” said Curiosity Project Manager Jim Erickson of JPL. …

Curiosity reversed course and drove out of Hidden Valley northeastward. On the way toward gaining a good viewpoint to assess a possible alternative route north of the valley, it passed over the pale paving stones on the ramp again. Where a rover wheel cracked one of the rocks, it exposed bright interior material, possibly from mineral veins.

More and more, the journey to Mount Sharp appears to be increasingly adventurous for the rover.

Curiosity’s journey continues

After more than a full Martian year, Curiosity has finally traveled beyond the area of its initial landing zone.

The 1-ton Curiosity rover has now cruised out of its landing ellipse, the area — about 4 miles wide by 12 miles long (7 by 20 kilometers) — regarded as safe ground for its August 2012 touchdown within Mars’ huge Gale Crater, NASA officials said.

The interesting factoid from this article is how much smaller this landing zone was for Curiosity compared to all other previous landers, illustrating how the technology has advanced during the last four decades since Viking.

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