Tag: geology

Curiosity looks ahead

9:36 am

Curiosity looks ahead
Click for full resolution. For original images go here and here.

Overview map
Click for interactive map.

Cool image time! The panorama above, taken by one of the navigation cameras on the Mars rover Curiosity on July 23, 2022, forms a nice bookend to yesterday’s panorama. Yesterday Curiosity looked back at its past travels. Today it looks forward at where it is almost certainly heading in the days ahead.

On the overview map to the right, the yellow lines indicate the approximate area viewed by the panorama. The large red dotted line marks the rover’s original planned route, abandoned when the science team found the terrain on the Greenheugh Pediment too rough for Curiosity’s wheels. The smaller red dotted line is my present guess as to the rover’s future route to get back on course.

The flat-topped mountain dubbed Kukenán by the science team has probably been one of the prime goals of the entire mission, from the beginning. Its almost vertical face has innumerable layers, all of which record in great detail the geological history of Mars and Gale Crater. As noted by Abigail Fraeman from the Jet Propulsion Laboratory on June 30, 2022:

Kukenán’s Earth namesake is a tepui, or distinctive isolated table-top mountain, found in South America. The Martian Kukenán is also somewhat flat topped and an impressive expression in Mt. Sharp’s topography. While it looks like it’s about the same size as the hills that bound it in the above Navcam image (“Deepdale” on the left and the edge of “Bolivar” on the right), this effect is just due to forced perspective. In reality, Kukenán is nearly five times farther away and over three times as tall as Deepdale! Curiosity’s strategic traverse path takes the rover right past Kukenán in about a kilometer or so, so this feature will become a familiar landmark rising in our windshield for months to come.

The science team will likely park Curiosity in the saddle of the gap ahead for at least a week and spend a lot of time documenting that cliff face with multiple cameras, since at this location the rover will have an excellent view of that entire face. As it gets closer the angle looking up will get steeper, thus making viewing of the upper layers more difficult.

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Curiosity looks back

11:49 am

Curiosity looks back
Click for full image.

Overview
Click for interactive map.

Cool image time! Normally I’d be hiking today, but since it is raining in southern Arizona at every mountain location we might want to go, I am forced to imagine hiking on Mars instead. The photo above, cropped to post here, was part of a mosaic of images taken on July 22, 2022 by the right navigation camera on the rover Curiosity.

Curiosity had just completed several drives that had it skirt around those two boulders visible in the center of the picture, as shown in the inset in the overview map to the right. The yellow lines indicate the approximate area covered by the photo. The blue dot marks Curiosity’s present location. The larger red dotted line the rover’s original planned route, with the smaller dotted line my guess as to the route the science team now plans to take to return to that course.

The rim of Gale Crater can be seen in the far distance, about 20 to 30 miles away and largely obscured by the winter dust that presently fills the atmosphere.

The science team had hoped to get close enough to these two boulders to touch them with the rover’s instruments, but decided to keep away because of both appeared a bit unstable.

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Collapsed dunes in Jezero Crater

10:31 am

Collapsed dune on Mars
Click for full image.

Cool image time! The photo above, cropped and reduced to post here, was taken on July 20, 2022 by one of high resolution cameras on the rover Perseverance. It shows what appears to be a collapsed dune on the floor of Jezero Crater.

The arrows mark the highest dune ridge line that suddenly ends at a cliff, with the sand that is piled up at its base appearing almost like it flowed like thick mud outward away from that cliff. Apparently, that material broke off in one single event sometime in the past.

Note the many parallel lines pointing outward from the base of the cliff. These lines appear to reflect the internal structure visible in the cliff itself. Somehow, when that sand collapsed, it flowed away while retaining some of that structure.

When this collapse happened is unclear. I don’t think it has happened recently, since Perseverance’s arrival, but I could be wrong.

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Martian terraces

12:51 pm

Overview map
Glacier country on Mars

Martian terraces
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on May 17, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists have labeled “Dipping layers against mound in Deuteronilus Mensae.”

Deuteronilus is the westernmost mensae region in the 2,000-mile-long strip of heavy glaciers found in the northern mid-latitudes that I dub glacier country. This photo, the location of which is marked by the white cross on the overview map above, is another example, though somewhat strange and puzzling. Normally the layers will dip away from the high point. Here, the layers dip towards the mound. I can think of only one explanation, that of prevailing winds causing the erosion in this unusual manner, but I also find that explanation very unsatisfactory.

The layers themselves illustrate the cycles that have shaped Martian geology, caused by the wide swings in the planet’s rotational tilt, from 11 to 60 degrees. When that tilt is high, the poles are warmer than the mid-latitudes, and water ice migrates from the poles towards the equator. When the tilt is low, the mid-latitudes are warmer, and the water ice heads back towards the poles. Thus, the many many layers the orbiters and rovers are now finding everywhere on Mars.

Right now scientists think, because Mars’ tilt is in the middle of these swings at 25 degrees, the planet is in equilibrium, with the water at the poles and mid-latitudes essentially going no where. This conclusion however is not yet confirmed.

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Perseverance gains a little height

11:47 am

View of Jezero Crater from Perseverance
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Overview map
Click for interactive map.

Cool image time! The photo above, rotated and cropped to post here, was taken on July 18, 2022 by the right navigation camera on the Mars rover Perseverance.

The view isn’t that remarkable, when compared to many other pictures from Mars. What makes it newly interesting is that it shows that Perseverance has gained a little elevation as it explores the base of the delta that flowed into Jezero Crater. It is no longer on the crater floor, but above it, though not by much.

You can see the far rim of Jezero Crater in the distance, obscured somewhat by the dust that builds up in the Martian atmosphere during the winter. You can also see the gentle left-to-right downward slope of material that flowed down from that delta some time in the past. Also, though the resolution isn’t good enough to show it, the helicopter Ingenuity probably sits somewhere near the center of this picture, just to the right of the nose of the biggest ridgeline.

The overview map on the right gives the context, with the yellow lines showing my estimate of the area viewed by the picture above. The blue dot is Perseverance, the green dot is Ingenuity. The red dotted line is my present guess as to the planned route of Perservance up onto the delta.

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Layered mesa on Mars

12:57 pm

Layered mesa on Mars
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Cool image time! The photo to the right, cropped and reduced to post here, was taken on May 26, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a mesa about three quarters of a mile in length that appears to be many-layered, from top to bottom.

The brightness of the mesa, compared to the surrounding plains, also emphasizes the different layers, though in this case it suggests two major epochs where the material being laid down in each was fundamentally different.

Or the difference could simply mean that the surrounding terrain is covered with dust, hiding its true color.

There is no question that winds in the thin Martian atmosphere have contributed to the erosion that formed this mesa, much like the buttes in the American southwest are shaped by winds. Whether water was a factor for this Martian butte is far less certain.

The overview map below provides context.
» Read more

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Icy scarps in the high southern latitudes of Mars

1:25 pm

Icy scallops in the high southern latitudes of Mars
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Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on May 30, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label “Patching Mantling Unit,” located at about 57 degrees south latitude in a region where scientists have found good evidence of near surface ice. The top layer, or mantle, is likely patchy because it has a high content of water ice and is sublimating away. That almost all the cliffs are south-facing, which in the southern hemisphere gets the least direct sunlight, supports this supposition. For example, in the crater at the bottom of the image the ice would have disappeared first from the north-facing interior rim slopes, with the sublimation slowly working its way northward. Thus we have that butte extending out from the north rim.

The global map below not only indicates the location of these scallops with the green dot, it illustrates the overall icy nature of most of the Mars.
» Read more

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The highest point on Mars

12:41 pm

The highest point on Mars
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Today’s cool image is cool not because of anything visible within it, but because of its location. The picture to the right, cropped to post here, was taken on May 27, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). While the terrain shown is a relatively featureless plain of craters and gullies not unlike the surface of the Moon, what we are really looking at is the peak of Mars’ tallest mountain, Olympus Mons.

That’s right, this spot on Mars sits about 70,000 feet above Mars’ mean “sea level”, the elevation scientists have chosen as the average elevation on Mars from its center. At 70,000 feet, this peak is more than twice as high as Mount Everest on Earth.

Yet you wouldn’t really know you are at this height if you stood there. The scale of this mountain is so large that this peak, which actually forms the southern rim of the volcano’s 50 to 60 mile wide caldera, is actually relatively flat. If you stood here, you would not see the vast distant terrain far below. Instead, you’d see an ordinary horizon line in the near distance only slightly lower than where you stand.
» Read more

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Collapse pits on Mars

2:08 pm

Elongated collapse pit on Mars
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Cool image time! The photo to the right, cropped to post here, was taken on May 21, 2022 and was today’s picture of the day from the high resolution camera on Mars Reconnaissance Orbiter (MRO). Dubbed “An Elongated Collapse Pit” by the science team, their caption explains:

This observation can help to tell whether or not there is a subterranean connection to this pit. As an added bonus, the much smaller depression to its south also appears to be another collapse pit.

This image had already been in my queue for a future cool image post, but since the scientists have posted it, it is time that I did as well.

In the inset I have brightened the image drastically to try to illuminate the darkest spots in both pits. The elongated pit appears to slope downward towards a hole in the southeast corner, while the interior of the second pit to the south remains completely dark. Both appear to suggest a void below that both reach.

The wider context image and overview map below shows that there is further evidence of more voids in this region of Mars, dubbed Ceraunius Fossae, because of its many north-south parallel fissures.
» Read more

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More lacy Martian rocks

9:59 am

lacy Martian rock
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Cool image time! Because the Curiosity team is presently conducting a drilling campaign at its present position in the lower mountains of Gale Crater, the rover has not moved in the past few weeks. At these times, the science team also has the rover’s other cameras do extensive surveys of the surrounding terrain, including high resolution mosaics by its high resolution camera.

To the right is one photo from the most recent mosaic, cropped to post here. It was taken on July 10, 2022, and shows one many layered rock on the ground near the rover. Though no scale is provided, I suspect the extended flake from this rock is somewhere between six to twelve inches long.

Another illustration of the alien nature of Mars. This flake could not exist on Earth, where the heavier gravity and atmosphere would have acted to break it.

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The colorful layers of the Martian north pole icecap

1:44 pm

Colorful layers in the Martian north pole ice cap
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Wider view
Click for full image.

Today’s cool image above, rotated, reduced, and annotated to post here, comes from today’s picture of the day for the high resolution camera on Mars Reconnaissance Orbiter (MRO), which in turn is a retrospective of a captioned image first taken in 2010. The photo to the right, rotated, cropped, and reduced to post here, shows a larger area to provide some context. For this image north is towards the top. The rectangle indicates the area covered by the picture above.

The ice cap at the north pole is about 600 miles across and a little less than 7,000 feet deep, made up of many layers that are a mixture of water ice and cemented dust and sand. From the picture’s caption:

In many locations erosion has created scarps and troughs that expose this layering. The tan colored layers are the dusty water ice of the polar layered deposits; however a section of bluish layers is visible below them. These bluish layers contain sand-sized rock fragments that likely formed a large polar dunefield before the overlying dusty ice was deposited.

The lack of a polar ice cap in this past epoch attests to the variability of the Martian climate, which undergoes larger changes over time than that of the Earth.

The overview map below provides some further context.
» Read more

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OSIRIS-REx’s sample grab at Bennu in 2020 proved the rubble-pile asteroid has far less cohesion than predicted

10:10 am

The post touchdown crater on Bennu

The OSIRIS-REx science team, using data gathered during the spacecraft’s sample grab at Bennu in 2020, has determined that the rubble-pile asteroid has far less cohesion than predicted, with its rubble behaving less like a solid object and more like the playground ball-pits found in amusement parks.

After analyzing data gathered when NASA’s OSIRIS-REx spacecraft collected a sample from asteroid Bennu in October 2020, scientists have learned something astonishing: The spacecraft would have sunk into Bennu had it not fired its thrusters to back away immediately after it grabbed dust and rock from the asteroid’s surface.

It turns out that the particles making up Bennu’s exterior are so loosely packed and lightly bound to each other that if a person were to step onto Bennu they would feel very little resistance, as if stepping into a pit of plastic balls that are popular play areas for kids.

The image above shows what the touch down crater looked like after the sample grab, taken from the video that was part of the press release. The false colors indicate the depth changes produced by the touch down. The final crater was 26 feet across and more than two feet in depth, far larger than expected. Moreover, the energy from the spacecraft’s thrusters as it lifted off had increased the size of that crater further, by about 40%.

These results about the asteroid’s lack of cohesion match the earlier results studying a different impact crater on Bennu.

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From the rim to the floor of Valles Marineris

5:01 pm

Overview map

From the rim to the floor of Valles Marineris
Click for full image.

For today’s cool Martian image, we begin from afar and zoom in. The overview map above shows the solar system’s largest canyon, Valles Marineris, 1,500 miles long, and 400 miles wide at its widest. The white dot on the north rim of the section of the canyon dubbed Melas marks the location of the photo to the right, rotated, cropped and reduced to post here and taken on January 28, 2011 by the wide angle context camera on Mars Reconnaissance Orbiter (MRO).

I have added elevation numbers to this picture to give it some understandable scale. From the rim to the interior canyon floor — a distance of about ten miles — the canyon wall drops about 19,000 feet. Compare this with Bright Angel Trail in the Grand Canyon, which from the rim to the Colorado River drops about 4,400 feet in about the same distance. The wall of Valles Marineris is about four times steeper.

Even that doesn’t give you the full scale. Having hiked down to that interior canyon floor, you are still about 10,000 feet above Valles Marineris’s main canyon floor, with fifteen more miles of hiking to go to reach it.

The white rectangle marks the area covered by the MRO high resolution image below.
» Read more

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Scientists: Impacts on rubble-pile asteroid are different than on planets

10:27 am

Landslide on Bennu from impact
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Using data collected by OSIRIS-REx at the asteriod Bennu, scientists have determined that the ejecta from impacts on a rubble-pile asteroid behaves in a very different manner than on planets with higher gravity.

Instead of flying away at about the same speed as the impactor and escaping into space, as expected in the weak gravity, the material is lifted up at a very slow speed, falls back down, and then rolls downhill like a landslide. The graphic to the right from the press release, reduced and enhanced to post here, illustrates what the scientists think happened when one of Bennu’s larger craters was created.

[M]ost of that material, called ejecta, returned to the surface and slid down the face of the asteroid, starting a wide avalanche that slowly rolled toward Bennu’s equator. Perry said the only way this could happen on a small object like Bennu, which is less than 500 meters (1,640 feet) in diameter and has low gravity, is if the dust had low or next to no cohesion.

“Because Bennu is so small, its escape velocity is less than a few tenths of a mile per hour, so any particle ejected faster than that would leave the surface,” he said. “These slow speeds are possible only if Bennu’s surface is weaker than we thought, even weaker than very loose, dry sand. This extremely low surface strength also means material on a slope is easily disturbed, and that’s what led to the landslide.”

In other words, the low cohesion prevents the impact’s energy from being transferred efficiently to the asteroid’s particles. They move, but only slowly, and thus end up sliding away more or less along the asteroid’s surface.

This discovery helps explain how these rubble-pile asteroids accumulate material, despite their low gravity.

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How did sand dunes get to the top of a Martian mesa?

1:51 pm

Sand dunes at the top of a Martian mountain
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on January 1, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and shows one of the peaks of a 5,000+ foot high mesa inside Juventai Chasma, one of Mars’ deep mostly-enclosed chasms north of Valles Marineris.

I grabbed this picture because its label, “Bedform Change Detection in Juventae Chasma”, suggested something had changed from past photos, probably related to the sand dunes that hug the upper slopes of this peak. Unfortunately, in comparing this image with the earliest high-res image taken by MRO back in February 2018, I could not spot any change, probably because the resolution of the pictures released is not as high as MRO’s raw images.

However, the caption written for that 2018 image tells us where that change has likely occurred:

This image reveals a unique situation where this small dune field occurs along the summit of the large 1-mile-tall [mesa] near the center of Juventae Chasma. The layered [mesa] slopes are far too steep for dunes to climb, and bedform sand is unlikely to come from purely airborne material. Instead, the mound’s summit displays several dark-toned, mantled deposits that are adjacent to the dunes and appear to be eroding into fans of sandy material.

In other words, somewhere in the full resolution image scientists have spotted a change in the bedform sands that make-up these high mountain dunes that hug the peak. Since the data so far has suggested that the source for the sand of these high elevation dunes likely comes from the mesa itself — not from any distant source — any change found will help confirm or disprove that hypothesis.

The white box indicates the area covered by the close-up higher resolution picture below. Also below is an overview map, showing both the location of this mountain in Juventai Chasma as well as Juventai’s location relative to Valles Marineris.
» Read more

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Engineers propose flying gliders on Mars

9:00 am

Proposed sailplane flights in Valles Marineris
Proposed sailplane flights in Valles Marineris. Click for full image.

Engineers at the University of Arizona are developing a prototype sailplane that they think could fly for long distances on Mars at higher altitudes than a helicopter and not be reliant on solar batteries.

Using dynamic soaring, the sailplane utilises increases in horizontal wind speed with gaining altitude to continue flying long distances. It’s the same process albatrosses use to fly long distances without flapping their wings and expending crucial energy.

After lifting themselves up into fast, high-altitude air, albatrosses then turn their bodies to descend rapidly into regions of slower, low-altitude air. With the force of gravity providing downward acceleration, the albatross uses this momentum to slingshot itself back to higher altitudes. Continuously repeating this process enables albatross and other seabird species to cover thousands of kilometres of ocean, flap-free.

It’s the inspiration for the sailplane’s own propulsion system, enabling it to cover the canyons and volcanoes dotted across the red planet currently inaccessible to Mars rovers.

The graphic above, figure 1 from the engineers’ research paper, shows one possible sailplane mission, deploying two gliders, one to observe the canyon wall and a second to survey the canyon floor. Both would become a weather station upon landing. While the paper doesn’t state a Mars location for this concept, the graphic strikes a strong resemblance to the section of Valles Marineris where scientists have recently taken “Mars Helicopter” high resolution images using Mars Reconnaissance Orbiter (MRO). This paper and those images might be related, or they could be illustrating the general interest by many scientists for this Mars’ location.

Regardless, the engineers are now planning test flights at 15,000 feet elevation, an elevation that will most closely simulate the atmosphere of Mars, on Earth.

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Scientists: Comet 67P/C-G’s make-up matches the rest of the solar system

9:33 am

A detailed review of the archived data from the Rosetta mission that studied Comet 67P/Churyumov-Gerasimenko closely in 2014-2016 now strongly suggests that the comet’s overall make-up closely matches the rest of the solar system.

“It turned out that, on average, [the comet’s] complex organics budget is identical to the soluble part of meteoritic organic matter”, explains [Nora Hänni of the University of Bern] and adds: “Moreover, apart from the relative amount of hydrogen atoms, the molecular budget of [comet 67P/C-G] also strongly resembles the organic material raining down on Saturn from its innermost ring, as detected by the INMS mass spectrometer onboard NASA’s Cassini spacecraft”.

“We do not only find similarities of the organic reservoirs in the Solar System, but many of [comet 67P/C-G]’s organic molecules are also present in molecular clouds, the birthplaces of new stars”, complements Prof. Dr. Susanne Wampfler, astrophysicist at the Center for Space and Habitability (CSH) at the University of Bern and co-author of the publication. “Our findings are consistent with and support the scenario of a shared presolar origin of the different reservoirs of Solar System organics, confirming that comets indeed carry material from the times long before our Solar System emerged.”

These results are not unexpected, but having those expectations confirmed was one of the main scientific goals of the Rosetta mission. Now, almost a decade later, the results are in.

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One of Perseverance’s two wind sensors damaged by wind-blown material

5:09 pm

According to the principal investigator for Perseverance’s two wind sensors, one was recently damaged by a wind-blown tiny pebble.

Pebbles carried aloft by strong Red Planet gusts recently damaged one of the wind sensors, but MEDA can still keep track of wind at its landing area in Jezero Crater, albeit with decreased sensitivity, José Antonio Rodriguez Manfredi, principal investigator of MEDA, told Space.com. “Right now, the sensor is diminished in its capabilities, but it still provides speed and direction magnitudes,” Rodriguez Manfredi, a scientist at the Spanish Astrobiology Center in Madrid, wrote in an e-mail. “The whole team is now re-tuning the retrieval procedure to get more accuracy from the undamaged detector readings.”

…Like all instruments on Perseverance, the wind sensor was designed with redundancy and protection in mind, Rodriguez Manfredi noted. “But of course, there is a limit to everything.” And for an instrument like MEDA, the limit is more challenging, since the sensors must be exposed to environmental conditions in order to record wind parameters. But when stronger-than-anticipated winds lifted larger pebbles than expected, the combination resulted in damage to some of the detector elements.

The term “pebble” implies a larger-sized particle than what probably hit the sensor. I suspect the “pebble” was no more than one or two millimeters in diameter, at the most.

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Strange pitted and isolated ridges on Mars

2:30 pm

Context camera image of isolated ridges
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on February 17, 2012 by the wide-view context camera on Mars Reconnaissance Orbiter (MRO). It shows a section of the northern lowland plains of Mars, latitude 31 degrees north, where several very inexplicable and isolated ridges can be seen.

One ridge meanders mostly in a north-south direction, while a second instead meanders east-west. The shape of both says that neither has anything to do with any past impact crater. In fact, their random snakelike shape doesn’t really fit any obvious explanation. For example, they do not fit the look of the many fossil rivers found on Mars, where the hardened and dry riverbed channel resists erosion and becomes a ridge when the surrounding terrain erodes away.

What geological process caused them? In the decade since this photo was taken the scientists who use MRO have only been able to snap a handful of high resolution images of these ridges. The image below is the most recent, covering the area in the white rectangle above.
» Read more

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Glacial features in a Mars crater at 29 degrees south latitude?

3:56 pm

Glacial features in Mars crater
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on January 2, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Simply labeled “slope features,” it was likely taken to monitor the gullies and streaks on the interior walls of this 4-mile-wide crater. Scientists have been using MRO to track the coming and going of frost on this crater’s interior walls since 2016.

Equally intriguing however are what appear to be squashed layers within the crater’s interior. These appear to be some form of glacial feature created by repeated climate cycles, similar to the glacial features routinely seen throughout the 30 to 60 degree mid-latitude strips north and south.

What makes the glacial features in this particular crater particularly intriguing is its location, as shown in the overview map below.
» Read more

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The lava tubes on the western slopes of Alba Mons as potential Martian colonies

12:20 pm

Lava tubes on western flank of Alba Mons
Click for full figure.

In a new paper detailing work they first began in 2019, scientists have now carefully mapped the extensive lava tubes that appear to radially descend westward from the caldera of Alba Mons, the volcano on Mars that has the largest surface area but with a relatively low peak.

The mapped population of 331 lava tube systems has a mean length of 36.2 km, with a total length in the western flank geologic map quadrangle of ∼12,000 km. Individual lava tube systems extend up to ∼400 km, and it is likely that some of our mapped lava tubes are connected such that the total number is actually smaller and lengths (average and maximum) longer.

The map above, figure 10 of their paper, shows volcanic ridges as yellow, collapsed lava tube segments as red, and collapsed lava tube on the volcanic ridge as maroon. The wider map below, shows where this region is located, and gives the larger context.
» Read more

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A thick and syrupy flow on Mars

1:06 pm

A thick and syrupy flow on Mars
Click for full image.

Overview map

Cool image time! The photo above, rotated, cropped, and reduced to post here, was taken on March 5, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as a “viscous flow feature,” which is another way of saying the flow was thick and syrupy.

Nor is such a flow unusual in this area of Mars. It is located in a region of chaos terrain dubbed Protonilus Mensae, which is also the central mensae region in the 2,000-mile-long strip in the northern mid-latitudes of Mars I label glacier country. The overview map above of Protonilus Mensae — covering about 500 miles in width — shows how common such flows are in this place. The black rectangles mark the locations of other cool images I have featured, as follows:

The red rectangle indicates the location of today’s cool image.

The glacial aspect of everything in this region is even more emphasized by the wider view provided by MRO’s context camera below.
» Read more

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New research suggests flowing water existed intermittently on Mars from 2.5 to 3.6 billion years ago.

9:26 am

Based on a study of alluvial fans on Mars, river sediment thought to have been placed at the foot of mountains, scientists have concluded that liquid water could have been flowing from as 2.5 to 3.6 billion years ago.

“We’ve known for decades that Mars had rivers and lakes around 3.5 billion years ago, but in the past few years there has been a growing body of evidence that substantial amounts of liquid water continued to erode the Martian surface for hundreds of millions of years,” said Morgan, lead author on “The global distribution and morphologic characteristics of fan-shaped sedimentary landforms on Mars” that appears in Icarus. “Water-formed landforms, such as river deltas and alluvial fans, are the most unambiguous markers of past climate. So we conducted a global survey for these features and explored patterns in their distribution and morphologic properties.”

Morgan and co-authors including PSI Senior Scientist Alan Howard found that alluvial fans are found at lower elevations than the more ancient valley networks, suggesting that stable liquid water became restricted to lower, warmer regions as Mars cooled and dried.

…What is particularly interesting about the Martian fans is that many formed much later than the valley networks, which have long been considered the strongest evidence for surface water on early Mars. Valley networks largely date to around 3.6 billion years ago, but alluvial fans date to 2.5 to 3 billion years ago.

This research merely increases the fundamental geological mystery of Mars. While the surface evidence strongly tells us that liquid water once flowed on the surface, no climate model exists that satisfactorily makes that possible. The atmosphere appears to have always been too cold and thin for liquid water.

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Perseverance’s first climb

12:03 pm

Perseverance's first climb
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Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera on the Mars rover Perseverance on June 16, 2022, shortly after it began its first climb up from the generally flat floor of Jezero crater and onto the delta that once in the far past flowed through a gap into that crater.

I have rotated the image about 8.5 degrees to make horizontal the crater floor and the distant rim of the crater (barely visible through the atmosphere’s thick winter dust). This shows that the rover was then climbing what appears to be a relative low angle grade, hardly as challenging as the serious grades that Curiosity has been dealing with now for the past two years in the foothills of Mount Sharp. Nonetheless, Perseverance has begun climbing.

To see where the rover is see the overview map from the start of this week. Unfortunately, I have been unable to determine the direction of this photo. It could be looking west, south, or east, based on features inside Jezero Crater. I therefore cannot tell you the distance to the rim, which depending on the direction, could be from five to twenty-five miles away.

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A major update from Curiosity’s science team

10:13 am

Panorama of Mars
Click for full image.

layered flaky rocks
Click for full image.

In a press release today, the Curiosity science team provided a major update on the rover’s recent travels in the mountain foothills of Gale Crater.

First and foremost was the new information about the rover’s wheels, which was buried near the bottom of the release:

The rover’s aluminum wheels are … showing signs of wear. On June 4, the engineering team commanded Curiosity to take new pictures of its wheels – something it had been doing every 3,281 feet (1,000 meters) to check their overall health. The team discovered that the left middle wheel had damaged one of its grousers, the zig-zagging treads along Curiosity’s wheels. This particular wheel already had four broken grousers, so now five of its 19 grousers are broken.

The previously damaged grousers attracted attention online recently because some of the metal “skin” between them appears to have fallen out of the wheel in the past few months, leaving a gap.

The team has decided to increase its wheel imaging to every 1,640 feet (500 meters) – a return to the original cadence. A traction control algorithm had slowed wheel wear enough to justify increasing the distance between imaging.

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A snakelike Martian ridge

1:21 pm

A snakelike Martian ridge
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Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on November 22, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team labeled a sinuous ridge. Make sure you also look at the full image. The ridge goes on to the south, but then fades way as an almost perfect ramp, only to have another even more wiggly but thinner north-south ridge begin only a few feet to the west.

Sinuous ridges like this are found in many places on Mars. Almost always their origin is thought the result of a former river channel that became a ridge when the surrounding softer material eroded away.

That explanation however does not seem to work for this ridge. It has too many other inexplicable features. For example, note how the peak of the ridge smoothly transitions from sharp to flat-topped. It has a soft appearance that is strengthened by the gap near the top.

It is almost as if this ridge is a kind of elongated sand dune! And guess what: The overview map below gives that explanation some believability.
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InSight team decides to shorten lander’s life to operate seismometer longer

9:49 am

The InSight science team has decided to continue to operate the lander’s seismometer through August rather than turning it off at the end of June, even though that longer use will drain InSight’s batteries sooner and kill the lander shortly thereafter.

The previous plan would have allowed the lander to survive through the end of the year, but would have meant no earthquake data would have been gathered after June.

To enable the seismometer to continue to run for as long as possible, the mission team is turning off InSight’s fault protection system. While this will enable the instrument to operate longer, it leaves the lander unprotected from sudden, unexpected events that ground controllers wouldn’t have time to respond to.

“The goal is to get scientific data all the way to the point where InSight can’t operate at all, rather than conserve energy and operate the lander with no science benefit,” said Chuck Scott, InSight’s project manager at NASA’s Jet Propulsion Laboratory in Southern California.

Apparently they have realized that it is now very unlikely that a dust devil will come by and clear the dust from InSight’s solar panels, so keeping the spacecraft alive longer — but getting no data — does not make sense.

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Has work begun on a dedicated helicopter mission to Mars?

12:42 pm

Overview map

The easternmost point in the Mars Helicopter traverse
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In my routine searches through the image archive for the high resolution camera on Mars Reconnaissance Orbiter, I recently came upon several images labeled “Candidate Mars Science Helicopter Traverse” that I at first thought referred to Ingenuity’s extended mission in Jezero Crater.

A closer look however revealed these photos have nothing to do with Ingenuity or Jezero Crater. Taken in November ’21, January ’22, and March ’22, the images instead cover parts of the south rim of Valles Marineris, the solar system’s largest canyon, and appear to be research for a future dedicated Mars helicopter mission. The overview map above shows the location of these photos by the black dots. Three locations have each been imaged twice to produce a stereoscopic view that can precisely measure the topography.

The photo to the right, cropped and reduced to post here, shows the easternmost image, taken November 3, 2021. Not only does it show ample flat areas, the picture captures an impressive avalanche flow coming down from that southern interior canyon slope.

All the images were requested by planetary scientist Edwin Kite of the University of Chicago. Though I tried several times to contact Dr. Kite to get more information, he unfortunately did not respond. It could be this work is still too preliminary and thus he does not wish to comment.

Nonetheless, the extent of the three sets of images give us a fair idea of the kind of missions Kite and others might be considering. From east to west the distance between the images is about four hundred miles, and covers a traverse of the southern interior slopes of Valles Marineris along that entire length. The photos look mostly at the base of the canyon’s slope, each showing clearly that a helicopter flying there would have plenty of landing spots.

Obviously this first dedicated Mars helicopter mission might not cover this entire distance. Right now these images could simply be the first tentative research on choosing potential landing areas. Regardless, it appears that at least one scientist has already concluded that Ingenuity has proven such helicopter missions make sense, and is beginning to target one of Mars’s most spectacular locations, Valles Marineris, for that mission.

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Water and dry ice at the Martian north polar ice cap

12:41 pm

water and dry ice at the Martian north pole
Click for original image. Click here for full image.

In our third Martian cool image of the day, we go to the north pole of Mars, as seen from orbit by the high resolution camera of Mars Reconnaissance Orbiter (MRO). Taken on March 30, 2022 and cropped and reduced to post here, this picture shows some of the distinct and unique geological features found only on the polar caps of Mars. From the caption by Candy Hansen of the Planetary Science Institute in Tucson, Arizona:

Both water and dry ice have a major role in sculpting Mars’ surface at high latitudes. Water ice frozen in the soil splits the ground into polygons. Erosion of the channels forming the boundaries of the polygons by dry ice sublimating in the spring adds plenty of twists and turns to them.

Spring activity is visible as the layer of translucent dry ice coating the surface develops vents that allow gas to escape. The gas carries along fine particles of material from the surface further eroding the channels. The particles drop to the surface in dark fan-shaped deposits. Sometimes the dark particles sink into the dry ice, leaving bright marks where the fans were originally deposited. Often the vent closes, then opens again, so we see two or more fans originating from the same spot but oriented in different directions as the wind changes.

The top layer of translucent dry ice falls as dry ice snow during the winter, than sublimates away with the arrival of spring. Since this photo was taken in autumn, we are looking at features left over from the activity from the spring and summer.

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Perseverance peers towards the rim of Jezero Crater

12:17 pm

Perseverance peers through winter haze
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Overview map
Click for interactive map.

In our second cool image from Mars today, the Mars rover Perseverance gives us its own long distance view of the dusty winter air inside Jezero Crater. The photo above, cropped and reduced to post here, was taken on June 16, 2022 by the rover’s left high resolution camera, and looks to the southwest towards the crater’s western rim.

As with today’s previous cool image from Curiosity, we can see several ranges, each with distance faded more by the dust that hangs in the air during the winter on Mars. In the foreground right is the nearest cliff of the delta that flowed into Jezero over time in the past. Next is a knob and ridge line, also part of that delta flow but farther away. Third are some farther ridges that might have been part of that flow but maybe not.

Faintest of all are the highest mountains that form the western ridge of Jezero Crater, barely visible in the haze.

The blue dot in the overview map to the right marks Perseverance’s approximate position when the photo was taken. The yellow lines my guess as to the area covered by the photo. The green dot marks Ingenuity’s present position after its last flight, much closer to the delta that I had predicted.

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