Tag: Mars

Scientists propose widespread deep groundwater on Mars

9:40 am

In a new study, scientists are now suggesting that widespread deep groundwater exists on Mars, and is the cause of the recurring slope lineae seen on many Martian slopes.

Previous theories for the cause of lineae proposed both dry and wet processes, all related to either near surface or atmospheric phenomenon. This new hypothesis is different, as it proposes deep groundwater as the source.

“We propose an alternative hypothesis that they originate from a deep pressurized groundwater source which comes to the surface moving upward along ground cracks,” Heggy says. “The experience we gained from our research in desert hydrology was the cornerstone in reaching this conclusion. We have seen the same mechanisms in the North African Sahara and in the Arabian Peninsula, and it helped us explore the same mechanism on Mars,” said Abotalib Z. Abotalib, the paper’s first author.

The two scientists concluded that fractures within some of Mars’ craters, enabled water springs to rise up to the surface as a result of pressure deep below. These springs leaked onto the surface, generating the sharp and distinct linear features found on the walls of these craters. The scientists also provide an explanation on how these water features fluctuate with seasonality on Mars.

This conclusion is most intriguing, but it is far from certain. Scientists have found a lot of lineae. For all of them to come from deep groundwater rising under pressure through fractures seems unlikely.

Nonetheless, this research indicates the growing belief among Mars researchers that water exists everywhere on Mars, and is accessible.

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Mars helicopter completes first test flight

9:28 am

The small helicopter that will fly autonomously as part of the Mars 2020 rover mission has successfully completed its first test flights here on Earth.

“We only required a 2-inch (5-centimeter) hover to obtain all the data sets needed to confirm that our Mars helicopter flies autonomously as designed in a thin Mars-like atmosphere; there was no need to go higher. It was a heck of a first flight,” [said Teddy Tzanetos, test conductor for the Mars Helicopter at JPL.]

The Mars Helicopter’s first flight was followed up by a second in the vacuum chamber the following day. Logging a grand total of one minute of flight time at an altitude of 2 inches (5 centimeters), more than 1,500 individual pieces of carbon fiber, flight-grade aluminum, silicon, copper, foil and foam have proven that they can work together as a cohesive unit.

This helicopter drone is a technology experiment, more focused on testing helicopter flying on Mars that doing science. If it proves to work, it will open up a whole new unmanned option for exploring the Martian surface. Imagine a helicopter that takes short hops from point to point. It will be able to reach locations a rover never could, and do it faster.

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How fast do things change on Mars?

12:46 pm

Looking for dune changes on Mars

On Earth, it is assumed that in a period of a dozen years a sand dune would change significantly. Wind and rain and the yearly cycle of the seasons would work their will, reshaping and moving the dune steadily from one place to another.

On Mars, we would be reasonable to expect the same. Yet, this might be a mistake, as illustrated by the two images on the right, taken by cameras on Mars Reconnaissance Orbiter (MRO) a dozen years apart of the same large dune located in a crater far to the south in the planet’s southern highlands. Both images have been cropped and reduced in resolution to show here. For the full images, go here for 2007 and here for 2019.

The top image was taken October 31, 2007 by MRO’s context camera. The bottom image was taken on January 29, 2019 by MRO’s high resolution camera. Though the context camera does not have the resolution of the high resolution camera, the difference is of less significance in this context.

Have things changed? Putting aside lighting differences, it does appear that the white patches have changed slightly in a variety of places. There also might be changes in the small dunes on the left of the image, at the base of the large central dune.

The white patches are probably what interests the scientists who requested the second image. Could this be snow or frost, as is thought to exist in other places? There are studies [pdf] that expect ice to exist inside craters near the south pole. Identifying changes here would help answer this question.

Overall, however, not much is different. Though dunes definitely change on Mars, they do so much more slowly than on Earth. And in some cases what look like dunes are not really dunes at all, but a form of cemented sandstone, exhibiting even fewer changes over long time spans.

I do not know if these dunes are of sand or sandstone. What the two images reveal is that in either case, things do not change on Mars at the same pace as they do on Earth. Even after three Martian years, the thin Martian atmosphere simply doesn’t have the same energy as on Earth, even though it can move things easier in the weak gravity.

While the pole caps of Mars change a lot seasonally, the rest of the planet evolves very slowly. Mars is no longer an active planet like the Earth. It is, in many ways, a dead planet, once alive with activity but now silent and relatively quiet.

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Rivers on Mars?

9:24 am

The uncertainty of science: A new study of Martian geology suggests that rivers ran on the surface are longer and later in the planet’s history than previously thought.

Seeking a better understanding of Martian precipitation, Kite and his colleagues analyzed photographs and elevation models for more than 200 ancient Martian riverbeds spanning over a billion years. These riverbeds are a rich source of clues about the water running through them and the climate that produced it. For example, the width and steepness of the riverbeds and the size of the gravel tell scientists about the force of the water flow, and the quantity of the gravel constrains the volume of water coming through.

Their analysis shows clear evidence for persistent, strong runoff that occurred well into the last stage of the wet climate, Kite said.

The results provide guidance for those trying to reconstruct the Martian climate, Kite said. For example, the size of the rivers implies the water was flowing continuously, not just at high noon, so climate modelers need to account for a strong greenhouse effect to keep the planet warm enough for average daytime temperatures above the freezing point of water.

The rivers also show strong flow up to the last geological minute before the wet climate dries up. “You would expect them to wane gradually over time, but that’s not what we see,” Kite said. The rivers get shorter—hundreds of kilometers rather than thousands—but discharge is still strong. “The wettest day of the year is still very wet.”

They also found that these rivers had been wider than those seen on Earth, which would make sense if there were few if any plant life to fix the banks in place, as on Earth. The lower Martian gravity probably plays an even larger role in this.

You can read the paper here. The study confirms many other previous studies of Martian surface features, which have repeatedly found evidence that liquid water once existed on Mars. That it found the water flowed later and more extensively only makes more difficult the deeper and probably biggest mystery of Martian geology, however, which is that scientists have not been able to come up with a historic atmospheric model that would allow that liquid water to exist. Mars today is too cold and its atmosphere is too thin for liquid water to flow, and the evidence from the past does not suggest an atmosphere different enough to change that.

It must have been different, but we don’t know how that was possible, based on the data we presently have. And this study makes solving that mystery even more difficult.

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Fresh crater in Martian northern lowlands

1:44 pm

Fresh impact crater in northern lowlands
Click for full image.

Today’s cool image could be a sequel to yesterday’s. The image on the right, cropped to post here, was one of the many images released from Mars Reconnaissance Orbiter’s (MRO) high resolution camera in March. The release, uncaptioned, calls this a “fresh impact crater.”

In many ways it resembles the craters I posted yesterday, with a splashed look and a crater floor with features that favor the north. Why that divot exists in the northern half of the floor is to me a mystery. The crater floor looks like a sinkhole to me, with material slowly leaking downward at that divot to cause this surface depression. Yet the rim screams impact. And yet, why the double rim? Was this caused by ripples in wet mud when the bolide hit?

Location of fresh impact crater

The crater itself is all by itself deep in those northern plains. You can see its location as the tiny white rectangle slightly to the left of the center in the overview image to the right. The giant Martian volcanoes can be seen at the image’s right edge, almost a quarter of a planet away. This is at a very low elevation on Mars, almost as deep as Hellas Basin.

For some fun context, this location is very close to where Viking 2 landed in 1976. The Mars 2020 rover meanwhile will land at this overview image’s left edge, on the western shore of the oval cut into southern highlands at about the same latitude as Olympus Mons, the largest volcano on the right. And InSight and Curiosity sit almost due south, with Curiosity in the yellow in the transition from green to orange, and InSight to the north in the green.

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Strange craters in the Martian northern lowlands

12:58 pm

Strange crater in the northern lowlands
Click for full image.

Cool image time! The image on the right, cropped and rotated to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and released in the monthly image dump provided by the science team. The release had no caption. It merely described this as a “Layered mound in crater.”

That is certainly what is is. However, layering suggests a regionwide process. The crater to the immediate northeast (the rim of which can be seen in the upper corner of this image), does not have the same kind of layering. (Be sure to click on the image to see that other crater.) Its crater floor is instead a blob of chaotic knobs, with the only layering scattered in spots along its north interior rim.

That the layering of both craters favors the north suggests a relationship, but what that is is beyond me. Prevailing winds? Maybe, but I don’t have the knowledge to explain how that process would work.

It is not even certain that these two craters were formed by impact. They are located in the northern lowlands where an intermittent ocean is believed to have once existed, and thus might be remnants of that ocean’s floor. That they both have a muddy appearance reinforces this hypothesis, but once again, I would not bet much money on this theory. The features here could also be expressing the effect of an impact on a muddy seafloor.

In either case the craters imply that the ocean that might have once been here existed a long enough time ago for these craters to form (either by impact or some other process) and then evolve. This has been a relatively dry place for a very long time.

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The layering at the Martian poles

2:56 pm

Layering in the east side of Burroughs Crater
Click for full image.

Layering in the west side of Burroughs Crater
Click for full image.

In the past month the science teams of both Mars Reconnaissance Orbiter (MRO) and Trace Gas Orbiter (TGO) have released images showing the strange layering found in Burroughs Crater, located near the Martian south pole.

The top image above is the MRO image, rotated and cropped to post here. To the right is a cropped and reduced section of the TGO image.

Though both images look at the inside rim of the crater, they cover sections at opposite ends of the crater. The MRO image of the crater’s east interior rim, with the lowest areas to the right, while the TGO image shows the crater’s northwest interior rim, with the lowest areas on the bottom. As noted at the TGO image site:
» Read more

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Jezero Crater: The landing site for the Mars 2020 rover

12:21 pm

Jezero Crater delta
Jezero Crater delta

At this week’s 50th Lunar and Planetary Science Conference in Texas, there were many papers detailing the geological, topographical, chemical, meteorology and biological circumstances at the landing sites for the 2020 Martian rovers, Jezero Crater for the U.S.’s Mars 2020 and Oxia Planum for Europe’s Rosalind Franklin.

Most of these papers are a bit too esoteric for the general public (though if you like to delve into this stuff like I do, go to the conference program and search for “Jezero” and “Oxia” and you can delve to your heart’s content).

Oxia Planum drainages

These papers do make it possible to understand why each site was chosen. I have already done this analysis for Rosalind Franklin, which you can read here and here. Oxia Planum is in the transition between the southern highlands and the northern lowlands (where an intermittent ocean might have once existed). Here can be found many shoreline features. In fact, one of the papers at this week’s conference mapped [pdf] the drainage patterns surrounding the landing ellipse, including the water catchment areas, as shown by the figure from that paper on the right.

With this post I want to focus on Jezero Crater, the Mars 2020 landing site. The image above shows the crater’s most interesting feature, an impressive delta of material that apparently flowed out of the break in the western wall of the crater.

This image however does not tell us much about where exactly the rover will land, or go. To do that, we must zoom out a bit.
» Read more

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Lava tubes on Alba Mons

12:28 pm

Lava tubes on the western slope of Alba Mons

During oral presentations today at this week’s 50th Lunar and Planetary Science Conference in Texas, scientists revealed [pdf] a map showing what they believe are numerous lava tubes flowing down the western slope of the giant Martian volcano Alba Mons.

The image on the right is taken from their paper. The red lines indicate collapsed tube sections, maroon collapsed sections on a ridge, and yellow volcanic ridges, which I assume are external surface flows. From their paper:

Lava tube systems … occur throughout the western flank, are concentrated in some locations, and are generally radial in orientation to Alba Mons’ summit. Lava tubes are typically discontinuous and delineated by sinuous chains of elongate depressions, which in many cases are located along the crests of prominent sinuous ridges. Lava tube systems occur as both these ridged forms with lateral flow textures and more subtle features denoted by a central distributary feature within the flat-lying flow field surface. Significant parts of the sinuous volcanic ridges show no collapse features, indicating a distinctive topographic signature for Alba Mons’ lava tubes.

Alba Mons is in some ways the forgotten giant volcano on Mars.
» Read more

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Streaky Mars: Slope streaks and recurring slope lineae

12:01 pm

New recurring lineae on Mars
Click for source paper [pdf].

Numerous presentations at this week’s 50th Lunar and Planetary Science Conference in Texas have focused on two different changing features on the Martian surface, dubbed slope streaks and recurring slope lineae (or RSLs, an example of an unnecessary and unwieldy acronym that I avoid like the plague).

These apparently are considered two different phenomenon (with some overlap), something I had not recognized previously. For example, one presentation [pdf] this week described slope streaks as:

…gravity-driven dark or light-toned features that form throughout the martian year in high-albedo and low-thermal-inertia equatorial regions of Mars. The distinctive features originate from point sources on slopes steeper than ~20°, follow the topographic gradient, extend or divert around small obstacles, and propagate up to maximum lengths of a few kilometers. The streaks brighten with time, sometimes become brighter than their surroundings, and fade away over timescales of decades. [emphasis mine]

An example can be seen here. This is in contrast to the recurring slope lineae, shown in the image above, which another paper [pdf] described as:

…dark linear features that occur on the surface of steep slopes in the mid-latitudes of Mars. These areas are warm, occasionally exceeding temperatures of 273-320 K. [Lineae] recur over multiple years, growing during warm seasons and fading away during colder seasons. Their apparent temperature dependency raises the possibility that liquid water is involved in their formation. [emphasis mine]

I have highlighted the key differences. While slope streaks are long lived and change slowly, lineae change with the Martian seasons. And the slope streaks appear to exist at lower latitudes. These difference means that the formation process of each must be also different.

The problem is that scientists still don’t know what causes either, though they have many theories, involving both wet and dry processes.

Most of the presentations at the conference this week focused on the recurring lineae, which I suspect is because of their seasonal aspect. This feature strongly suggests a water-related source for the lineae, and everyone who studies Mars is always focused on finding sources on Mars where liquid water might be found. Also, slope streaks appear more often in dunes, which also strongly suggests a dry process. One paper, however, did a comparison study of lineae with one specific kind of dune slope streak to see if the freatures might be related.

The most interesting result [pdf] for all these papers documented the apparent increase in recurring lineae following the global dust storm last year. The image at the top of that post is from this paper, and shows a fresh lineae where none had been prior to the storm. From the paper’s abstract:
» Read more

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Land of mesas

9:44 am

Ariadnes Colles
Click for full image.

Cool image time! The Mars Odyssey science team today released the image on the right, cropped and rotated to show here, of a region on Mars named “Ariadnes Colles.”

The term colles means hills or knobs. The hills appear brighter than the surrounding lowlands, likely due to relatively less dust cover.

This is certainly a place with lots of hills, or to be more precise, mesas, as many of them seem to be flat topped.

The lack of dust cover on the tops is probably because, like on Earth, the winds blow much better once you get a bit above the surface. (This is why sailing ship builders kept adding higher and higher sails to their ships, until the top sails of clipper ships rose a hundred-plus feet above the deck.) These better winds clean off the mesa tops, just as they did to the solar panels on the rovers Opportunity and Spirit several times during their long missions.

Ariadnes Colles is another example of Martian chaotic terrain. Since this region is located deep in the cratered and rough southern highlands of Mars, the erosion that created these mesas was likely not water-flows. Was it wind? Ice?

Your guess is as good as anyone’s.

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Snow on Mars?

1:10 pm

Snow on Mars?
Click to see full image.

At today’s presentations at the 50th Lunar and Planetary Science Conference in Texas, scientists showed images and data [pdf] suggesting that many of the Martian gullies found on cliff faces are formed when the dust layer protecting underlying snow gets blown away and the exposed snow/ice then melts.

The image on the right was taken by the high resolution camera of Mars Reconnaissance Orbiter (MRO) in 2009, and has been cropped to post here. The white streaks are what they suggest is exposed ice/snow.

From their paper [pdf]
» Read more

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Test drone maps ice cave in Iceland

10:23 am

Engineers have tested a prototype lidar-equipped drone by flying it through a lava tube in Iceland and using it to automatically map the tube.

While a cave-exploring drone on Earth may use propellers, free-flying spacecraft exploring caves on the Moon, where there is practically no atmosphere, or in the thin air of high altitude lava tubes on Mars’ giant volcanoes, would have to use small thrusters. The mission of the terrestrial drone deployed at the Lofthellir Ice Cave focused on validating the idea of using a drone-equipped LiDAR to safely navigate and accurately map rock and ice inside a dark lava tube in the absence of GPS or any prior map.

Under a research contract with NASA, Astrobotic has developed a custom navigation software product, known as AstroNav, to give drones and small free-flying spacecraft the ability to autonomously explore and map subterranean environments. AstroNav employs both stereo vision and LiDAR, works without GPS or previously stored maps, and can operate in real-time while a novel environment is explored at a high rate of speed.

…”The Astrobotic drone and LiDAR performed exactly as we had hoped, and was able to help us map the Lofthellir Lava Tube in 3D within minutes” says Lee. “We now have a highly accurate model of the shape and dimensions of the cave, and of the configuration of its many rocky and icy features, such as rock falls, ice columns, and micro-glaciers.”

The concept is an excellent one, especially for exploring the caves and pits of Mars. This test however only checked out the lidar. A drone that could do this on either Mars or the Moon does not yet exist.

I have posted their video of the flight below the fold.

Note: Thanks to reader Eddie Willers for noting that I mistakenly located this research in Greenland, not Iceland. Post now corrected.
» Read more

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Cost for Mars 2020 rover up 15%

9:42 am

Because of cost overruns in building three instruments for the Mars 2020 rover, its total budget will rise by 15%, forcing NASA to trim budgets elsewhere in its planetary program.

There are small efficiencies to be gained internally in Mars 2020, Glaze says, which, like its predecessor Curiosity, is being developed by NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. Some work can be postponed, some timelines tightened; the end of the Opportunity rover, which expired late last year on Mars, will help. But it is expected the costs will largely be borne by trims to the operations of existing Mars missions and funds the agency sets aside for future missions, including the return of the rock samples that Mars 2020 will collect. “We tried to spread it so no one is feeling all of the pain,” Glaze says.

For a government program costing almost $2.5 billion, this overage is remarkably small. What is more significant is that the rover appears on schedule for launch in July 2020.

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Mars likely has many large and extensive cave systems

1:56 pm

Mamers Valles

More caves on Mars! This week the Lunar and Planetary Institute and the Johnson Space Center are jointly holding the 50th Lunar and Planetary Science Conference in Texas. I have been going over the program, and will be posting reviews of some of the more interesting results all this week.

We begin with caves, which should not be surprising to my regular readers. As a caver who also knows their value for future space colonists, I am always attracted to new discoveries of cave passages on other worlds. Today’s however is a doozy.

The image to the right is of Mamers Valles on Mars, what scientists have dubbed a fretted valley, a common feature in the transition zone between the low altitude northern plains and the southern highlands. It comes from a paper [pdf] with the typically unexciting scientific title, “Fretted channels and closed depressions in northern Arabia Terra, Mars: Origins and implications for subsurface hydrologic activity.”

What the scientists really means here is that their research strongly suggests that Mars has a very large and very extensive number of underground drainage systems, which have caused collapses on the surface that often resemble meandering river canyons, such as seen above. As they explain:
» Read more

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Curiosity has another computer crash

8:53 am

Since March 6 all activity from Curiosity seemed to stop, with no images and no science team updates. The reason? The rover had experienced another computer crash and reboot:

Curiosity experienced a computer reset on its Side-A computer on Wednesday, March 6, 2019 (Sol 2,339), that triggered the rover’s safe mode. This was the second computer reset in three weeks; both resets were related to the computer’s memory.

The mission team decided to switch from the Side-A computer back to the rover’s Side-B computer, which it operated on for most of the mission until November of 2018. Side-B recently experienced its own memory issue; the team has since further diagnosed the matter, reformatting the Side-B computer to isolate areas of “bad” memory. As of today, Curiosity is out of safe mode, and the team is configuring the rover for new science operations in the clay unit. Curiosity is expected to return to science operations as early as Wednesday.

This news is worrisome. The track record for spacecraft with increasing computer problems is that they never get better. Instead, the problem steadily worsens until operations become limited or even impossible. In the meantime engineers work wonders to extend the mission, but in the end this is a battle they appear to always lose.

We are beginning to see this pattern with Curiosity. Both of its computers have now experienced problems. It appears they have a better handle on the problems with the back-up computer (Side-B), so that is why they have switched back to it. Should its own memory issues continue to deteriorate however the rover will be in serious trouble, as the Side-A computer has proven to be very unreliable.

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New analysis supports catastrophic floods and intermittent ocean on Mars

7:03 pm

The intermittent ocean at the outlet to Marineris Valles

A new analysis of Martian data once again suggests that an intermittent ocean once existed in the planet’s northern hemisphere, and that it was fed by catastrophic floods coming down from the volcanoes through Marineris Valles.

“Our simulation shows that the presence of the sea would have attenuated cataclysmic floods, leading to shallow spillovers that reached the Pathfinder landing site and produced the bedforms detected by the spacecraft,” said [lead scientist Alexis Rodriguez].

The team’s results indicate that marine spillover deposits contributed to the landscape that the spacecraft detected nearly 22 years ago, and reconcile the mission’s in situ geologic observations and decades of remote-sensing outflow channel investigations.

The sea bears an uncanny resemblance to the Aral Sea on Earth in that in both instances they lack distinct shoreline terraces. Its rapid regression over shallow submerged slopes resulted in rates of shoreline front retreat too fast for the terraces to form. The same process could partly account for the long-recognized lack of northern plains shorelines.

“Our numerical simulations indicate that the sea rapidly became ice-covered and disappeared within a few thousand years due to its rapid evaporation and sublimation. During this time, however, it remained liquid below its ice cover,” said PSI Senior Scientist Bryan Travis, a co-author in the paper.

The map above shows the outlet region to the west and north of Marineris Valles. (The paper from which it is adapted is available on line here.) It shows that inland sea, created by the catastrophic floods. Because it sits at a lower elevation than the plains to the north, the floods that entered it ponded there, where they dried up. Only when the floods were at their highest did the water spill out into the northern plains.

In reading the paper, it confirms many of the suppositions I myself have made in my frequent posts analyzing numerous Mars Reconnaissance Orbiter (MRO) images, such as the lack of a clear shoreline because the ocean was short-lived. As it dried up its edge left patches of shoreline, at different elevations and in pondlike patterns, almost like the beach debris left behind by the tide.

The paper also shows that some of my guesses were not quite correct. For example, this new analysis says that the catastrophic floods only partly carved out the chaos terrain of Hydraotes Chaos, rather than do it all as I supposed here. Instead, the floods contributed, but much of the erosion occurred when the short-lived inland sea existed here, eroding away at the mesas from all sides.

Read it all. Though this remains a simulation based on what is presently very incomplete data and thus has many uncertainties, it will give you a much deeper understanding of what we presently theorize about the past geological history of Mars.

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A gathering of dust devils

9:51 am

Dust devil tracks
Click for full resolution image.

A bunch of cool images! The European Space Agency (ESA) today released more than a dozen Martian images taken by the camera on its Trace Gas Orbiter spacecraft.

In addition to a snapshot of InSight and its landing area, “The images selected include detailed views of layered deposits in the polar regions, the dynamic nature of Mars dunes, and the surface effects of converging dust devils.” The release also included images showing details of two of Mars’ giant volcanoes, Olympus Mons and Ascraeus Mons.

The image I have highlighted to the right, reduced to post here, shows a spot on Mars where for some unknown reason dust devils love to congregate.

This mysterious pattern sits on the crest of a ridge, and is thought to be the result of dust devil activity – essentially the convergence of hundreds or maybe even thousands of smaller martian tornadoes.

Below is a side-by-side comparison of this image (on the right) with a Mars Reconnaissance Orbiter (MRO) image taken in 2009 (on the left).
» Read more

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Opportunity’s parting shot

4:31 pm

Opportunity's last panorama
Click for full image.

The Opportunity science team today released the last full 360 degree panorama taken by the rover last spring, prior to the global dust storm that ended its fifteen year mission on Mars.

Over 29 days last spring, NASA’s Mars Exploration Rover Opportunity documented this 360-degree panorama from multiple images taken at what would become its final resting spot in Perseverance Valley. Located on the inner slope of the western rim of Endurance Crater, Perseverance Valley is a system of shallow troughs descending eastward about the length of two football fields from the crest of Endeavor’s rim to its floor.

“This final panorama embodies what made our Opportunity rover such a remarkable mission of exploration and discovery,” said Opportunity project manager John Callas of NASA’s Jet Propulsion Laboratory in Pasadena, California. “To the right of center you can see the rim of Endeavor Crater rising in the distance. Just to the left of that, rover tracks begin their descent from over the horizon and weave their way down to geologic features that our scientists wanted to examine up close. And to the far right and left are the bottom of Perseverance Valley and the floor of Endeavour crater, pristine and unexplored, waiting for visits from future explorers.”

If you click on the image above you can go to the full image and zoom and scan across it.

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Martian massive landslides

1:24 pm

Though scientists have found some evidence of slow erosion and change on the Martian surface, it is today generally inactive. While the weak wind of Mars’ thin atmosphere continues to work its will, and the likely presence of underground frozen water acts to shift the surface shape as the seasons come and go, none of this happens quickly.

Essentially, Mars is a quiet place.

Once however catastrophic events took place, gigantic floods flowing down to the east from the planet’s huge volcanoes to carve out Marineris Valles, the solar system’s largest known canyon. As that water rushed eastward it ripped the terrain apart quickly, creating deep side canyons, drainage valleys, and chopped up regions now dubbed as chaos terrain, multiple mesas separated by numerous fissure-like canyons.

Overview of Marineris Valles and landslide

The overview map on the right shows Valles Marineris and its drainage to the east and north into the vast northern plains of Mars. It also shows the location of one of the largest regions on Mars of chaos terrain, dubbed Hydraotes Chaos, located close to the mouth of this gigantic drainage system more than 2,500 miles long.

Massive Martian landslide
Click for full image.

Recently scientists have used the high resolution camera on Mars Reconnaissance Orbiter (MRO) to begin taking images of the massive landslides on the face of the mesa north of Hydraotes Chaos that was hit directly by these floods. The location of the most immediately interesting of these landslide images is also indicated on this overview image.

To the right is that image, rotated, cropped, reduced, and annotated to post here. The white boxes indicate two full resolution sections that I highlight below at full resolution.

This image shows that full cliff. The total drop from the plateau at the top to the floor where Hydraotes Chaos is located to the south is approximately 8,200 feet, almost exactly comparable to the depth of the north rim of the Grand Canyon.

The image shows numerous evidence of avalanches and erosion, both at its base and at its rim. None of these avalanches likely occurred during those catastrophic floods, but long afterward.
» Read more

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