Tag: geology

Layered mesas in Martian chaos

12:27 pm

Layered mesas in Martian chaos
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on May 19, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a 2,500 to 3,000-foot-high mesa with what the scientists call “bedrock layers”, most obvious as the lower terraces on the mesa’s western slopes.

What makes this mesa especially interesting is its overall shape. It appears as if something has taken a bite out of it, resulting in that bowl-like hollow on the mesa’s southern half.

Was this caused by an impact? Or has some other long term Martian processes caused it?

This mesa is just one of many mesas in a region of chaos terrain dubbed Hydraotes Chaos. Such chaos terrain is thought to form when erosion processes, possibly glacial in nature, that carve out canyons along faultlines, leaving behind mesas with randomly oriented canyons cutting in many directions.
» Read more

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More deterioration to Curiosity’s worst wheel

12:13 pm

Comparison of changing damage from Feb to Sept 2024
For original images go here, here, and here.

The science team for the Curiosity Mars rover on September 22, 2024 did another survey of its damaged wheels using the close-up camera on the end of the rover’s arm, and though most of the pictures appear to show the situation remains stable, the one wheel that has consistently shown the worst damage now shows some additional deterioration since February 2024.

To the right are comparison pictures, with the February 2024 picture on top and two new September 22, 2024 images showing the same damaged area, though from a different angle, on the bottom. (The technical captions for the bottom images can be found here and here.) I have labeled the treads, dubbed growsers, to make it easier to understand how the pictures all line up.

Previous images have looked down at the large damaged area from growsers 1 to 4, and since it was first spotted in 2022 showed it to be growing, but very slowly. The new pictures show that same damaged area from the side, which reveals that the zig-zag divider between growser #3 and growser #4 has now collapsed, so that this whole damaged area is now a major depression, as indicated by the two arrows.

Overall, the rover’s wheels appear to surviving the rough terrain of the foothills of Mount Sharp, though it is clear that care must continue to be taken to extend their life for as long as possible. That the rover has six wheels gives it a lot of redundancy, so that even if this one wheel eventually fails the rover will likely be able to continue to rove, but with some limitations. This wheel is the left middle wheel, which is helpful, as it is less necessary than the four corner wheels. [Update: According to a rover update today, this wheel is the right middle wheel, which contradicts an earlier report which described this as the left middle wheel. I note this contradiction for accuracy.]

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Land of cracks

1:26 pm

Land of cracks

Cool image time! The picture to the right, cropped to post here, was taken on June 28, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled a “terrain sample,” it was likely taken not as part of any specific research project but to fill a gap in the camera’s schedule in order to maintain its proper temperature. When the camera team needs to do this, they try to pick something interesting, but don’t always have that option.

In this case, the landscape available included the channel shown to the right. About a half mile wide and only about fifty feet deep, the floor of this canyon appears to have a lot of trapped dust, forming ripple dunes, along with a lot of knobby protrusions, likely small mesas. The canyon walls appear layered, with the erosion processes producing different features on opposite sides. On the southeast the layers appear to produce distinct terraces, while on the northwest the cliff is very steep at the top and then forms a long gently descending slope that appears formed of alluvial fill (from that cliff) and formed from erosion and landslides.
» Read more

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Some new “What the heck?” geology on Mars

1:12 pm

What the heck is going on here?
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken on April 21, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

My first reaction on seeing this picture was to scratch my head? What am I looking at? Are those fluted dark features going downhill to the south, or uphill to the north? What are they? Are they slope streaks? Avalanches? How do they relate to the flat-topped ground in the middle of the picture?

I have made it easier for my readers to interpret the picture by adding the “low” and “high” markers. We are looking at two parallel thin mesas about 1,400 feet high, with the saddle between them only dropping about 350 feet.

But what about the dark fluted features? To understand what these are requires more information.
» Read more

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Perservance looks back from on high

10:25 am

Perservance's view looking back down Neretva Vallis
Click for original image.

Cool image time! The picture above, cropped to post here, was taken on September 9, 2024 by the left navigation camera on the Mars rover Perseverance, looking east and back along the route from which the rover had come.

The view is somewhat more spectacular than most Perseverance images because the rover took it during its on-going climb up unto the rim of Jezero Crater, as shown by the overview map below. The blue dot marks Perseverance’s present position, while the yellow lines indicate the area covered by the picture above, taken several days earlier.

The haze in the picture also suggests that the local dust storm first noted in late August might be clearing somewhat. This isn’t certain, however, as the previous picture was using the rover’s high resolution camera to look at distant hills (thus more obscured), while the picture above was taken by the left navigation camera looking more widely and at nearer objects.

Overview map
Click for interactive map.

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New gravity map of Mars released

9:09 am

New global map of Mars gravity field
Click for original image.
Using both seismological data compiled over four years by the InSight Mars lander as well tiny changes in the orbits of Martian satellites, scientists have now created a global gravity map of the red planet, indicating the regions below the surface that are either low or high density.

That map is above, annotated by me to indicate some of Mars’ major surface features.

The density map shows that the northern polar features are approximately 300-400 kg/m3 denser than their surroundings. However, the study also revealed new insights into the structures underlying the huge volcanic region of Tharsis Rise, which includes the colossal volcano, Olympus Mons.

Although volcanoes are very dense, the Tharsis area is much higher than the average surface of Mars, and is ringed by a region of comparatively weak gravity. This gravity anomaly is hard to explain by looking at differences in the martian crust and upper mantle alone. The study by Dr Root and his team suggests that a light mass around 1750 kilometres across and at a depth of 1100 kilometres is giving the entire Tharsis region a boost upwards. This could be explained by huge plume of lava, deep within the martian interior, travelling up towards the surface.

I once again note that the largest impact basin on Mars, Hellas Basin, sits almost exactly on the planet’s far side from Tharsis, and appears to have a light density. This contrast once again makes me wonder if the origin of that impact and the Tharsis Bulge are linked.

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A fluted mesa on Mars

1:27 pm

A fluted mesa on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on July 9, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team labels a “silica-rich mound”, as indicated by the bright streaks on all the high ridge points.

The flat-topped mesa on the right drops about 200 feet to the valley floor. The rims of that depression to the west rise about 50+ feet higher, while mesa nose in the upper left rising another 50+ feet more.

Was the depression caused by an impact? If so, the landscape has changed radically since that impact occurred, with most of the surrounding terrain eroded away. The two flat-topped mesas hint at the ancient surface when that impact occurred.

A wider view however raises questions about this impact theory.
» Read more

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Scientists re-create on Earth the sublimation of Mars’s winter mantle of dry ice

11:32 am

Spiders created on Earth
Click for original image.

Scientists have successfully re-created on Earth the process on Mars that creates the unique “spider” formations seen in the the Martian south pole region, produced when the winter mantle of dry ice begins to sublimate away into a gas.

The study confirms several formation processes described by what’s called the Kieffer model: Sunlight heats the soil when it shines through transparent slabs of carbon dioxide ice that built up on the Martian surface each winter. Being darker than the ice above it, the soil absorbs the heat and causes the ice closest to it to turn directly into carbon dioxide gas — without turning to liquid first — in a process called sublimation (the same process that sends clouds of “smoke” billowing up from dry ice). As the gas builds in pressure, the Martian ice cracks, allowing the gas to escape. As it seeps upward, the gas takes with it a stream of dark dust and sand from the soil that lands on the surface of the ice.

At the south pole, the ground below the mantle is stable enough that each winter the trapped CO2 gas follows the same path to the same points where the dry ice cracks, slowly creating “tributaries” that combine to form the spider formations.

The picture to the right, cropped, reduced, and sharpened to post here, comes from figure 9 of the paper [pdf]. It shows the lab-created spiders formed by this simulated process, thereby confirming this hypothesis about how the spiders form.

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A map of Io’s hot spots based on Juno data

1:12 pm

The hot spots on Io
Click for original image.

The uncertainty of science: Using the JIRAM infrared camera on the Jupiter orbiter Juno, scientists have now created a global map of volcanic activity, showing where it appears the hottest and greatest activity is located.

That data is illustrated by the graphic to the right, taken from figure 1 of the paper. The top row shows the coverage of the planet, with Io’s southern hemisphere getting the fewest observations. The bottom row shows the observed regions with the greatest heat. This quote from the abstract is most revealing:

Using JIRAM, we have mapped where volcanoes are producing the most power and compared that to where we expect higher heat flow from the interior models. Our map doesn’t agree with any of these models very well. JIRAM observed more volcanic activity at the poles than we expected to see based on previous observations. However, since the south pole was only observed twice, it’s possible that these observations don’t represent the average volcanic activity of the south pole. Very bright volcanoes that may have been continuously active for decades were also imaged during these Juno fly-bys, some of which are nearer the poles than the equator.

The conflict between the data and the theories could very well be explained simply by the short term nature of these observations. The models could very well be right, over centuries. For example, the new volcano discovered by Juno is near the equator, suggesting with time those models will turn out to be correct.

Or not. A lot more observations will have to be made of Io before any model of its volcanic activity can be considered trustworthy.

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Juno discovers new volcano on Io

10:24 am

New volcano on Io
Click for original image.

By comparing images taken twenty-seven years apart by the the Jupiter orbiters Galileo and Juno, scientists have discovered that during that time a new volcano appeared on the volcano-strewn Jupiter moon Io.

The two pictures to the right show the surface change on Io during those 27 years.

Analysis of the first close-up images of Io in over 25 years, captured by the JunoCam instrument on NASA’s Juno mission, reveal the emergence of a fresh volcano with multiple lava flows and volcanic deposits covering an area about 180 kilometres by 180 kilometres. The findings have been presented at the Europlanet Science Congress (EPSC) in Berlin this week.

The new volcano is located just south of Io’s equator. Although Io is covered with active volcanoes, images taken during NASA’s Galileo mission in 1997 did not see a volcano is in this particular region – just a featureless surface.

If anything, it has been somewhat surprising how little change the new Juno images have found on Io’s surface, considering its intensely active volcanic geology, with volcano plumes from eruptions captured in images repeatedly. Some volcanoes have shown change, but new features such as this new volcano have not previously been identified.

At the same time, the amount of high resolution imagery of the planet’s surface has been somewhat limited. Galileo sent back far fewer pictures than planned because its main antenna never deployed, and Juno had only a handful of close fly-bys. It will take a mission dedicated to studying Io to better map its violent surface.

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The reasons why Mars two polar caps are so different

1:06 pm

The Martian north pole
The Martian north pole.

The Martian south pole
The Martian south pole.

Elevation scale bar
What the colors mean in terms of elevation

A new paper, in review for the past year, has now been published describing the differences between the north and south poles of Mars, the most fundamental of which involve the planet’s orbit and the different elevations of the two poles, with the south pole three to six miles higher in altitude (as indicated by the colors on the maps to the right).

The cumulative data has allowed the researchers to explain why — when the thin winter cap of dry ice sublimates away in the spring — the process at the south pole results in spiderlike features that get enhanced from year to year, but in the north pole that sublimation process produces no such permanent features.

In both cases, the spring sunlight passes through the clear winter mantle of dry ice to heat its base. The sublimated trapped CO2 gas builds up, until the pressure causes the mantle to crack at weak spots. In the south that trapped gas flows uphill each spring along the same paths, carving the riverlike tributaries dubbed unofficially as “spiders” and officially as “araneiform terrain.”

Geophysicist Hugh Kieffer described that process in 2006. A few years later, [Candice] Hansen [the new paper’s lead author] followed up with her own model for the north polar cap, which also displays fans in the spring.

She found that the same phenomena occur in the north, but rather than relatively flat terrain, these processes play out across sand dunes. “When the Sun comes up and begins to sublimate the bottom of the ice layer, there are three weak spots – one at the crest of the dune, one at the bottom of the dune where it meets the surface and then the ice itself can crack along the slope,” Hansen said. “No araneiform terrain has been detected in the north because although shallow furrows develop, the wind smooths the sand on the dunes.”

There is also a lot more dust in the north, including a giant sea of dunes that circles the polar cap. In addition, the northern winter is shorter due to the planet’s orbit, and takes place during the annual dust storm season, causing there to be more dust concentrated within the northern ice. All of these factors make the the dunes and general surface in the north is more easily smoothed by the wind.

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A crack on Mars more than 600 miles long

2:18 pm

A crack on Mars more than 600 miles long
Click for original image.

Cool image time! The picture to the right, cropped and reduced to post here, was taken on March 29, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this “troughs in Labeatis Fossae.” On Mars, the word “fossae” is used to indicate regions where there are a lot of parallel fissures. Though there are a few examples where such fissures might have been caused by the movement of ice or water, carving out the channel, in almost all cases this is not the cause. Instead, fossae are usually formed when the surface stretches, either because underground upward pressure pulls it apart, or because there is a sideways spread at the surface. The resulting cracks are generally considered what geologists call “grabens,” depressions caused at faultlines when the ground on either side moves apart in some manner.

In this case the break in the trough proves this is a graben, though why it broke at this spot is not clear.
» Read more

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Dust storm in Jezero Crater

10:14 am

Overview map
Click for interactive map.

Dust storm in Jezero Crater
Click for original image.

An update today from the science team for the Mars rover Perseverance included the picture to the right, cropped, reduced, and sharpened to post here and taken by the rover on August 20, 2024. As the update noted,

It is dust-storm season on Mars! Over the past couple of weeks, as we have been ascending the Jezero Crater rim, our science team has been monitoring rising amounts of dust in the atmosphere. This is expected: Dust activity is typically highest around this time of the Martian year (early Spring in the northern hemisphere). The increased dust has made our views back toward the crater hazier than usual, and provided our atmospheric scientists with a great opportunity to study the way that dust storms form, develop, and spread around the planet.

The yellow lines on the overview map above indicate the approximate direction of the photo. The blue dot marks Perseverance’s present position, with the red dotted line its planned route and the white dotted line its actual travels.

At the moment this dust storm is localized to the region around Jezero Crater, and based on past seasonal dust storms, is not expected to expand to a global storm.

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Curiosity takes another look south into Gediz Vallis

2:18 pm

Looking south inside Gediz Vallis

Overview map
Click for interactive map.

Cool image time! As it has been more than a month since I lasted posted a cool landscape image from the Mars rover Curiosity, it seemed time to upload the panorama above, changed not at all to post here and taken by the rover’s right navigation camera on September 4, 2024.

The blue dot on the overview map to the right marks Curiosity’s present position. The yellow lines indicate the approximate direction of the panorama’s view. The red dotted line indicates Curiosity’s planned route, with the white dotted line marking its actual path. After spending most of the last month on a drilling campaign at the southernmost point of its travels, the science team had Curiosity retreat northward, where it will eventually head uphill to the west to swing around that mountain to head south in a parallel canyon.

The panorama looks into the slot canyon Gediz Vallis that Curiosity has been exploring for a little more than a year. The light colored mountains are what the scientists call the sulfate-bearing unit, a region on the higher slopes of Mount Sharp that is likely to have a very alien geology and chemistry, when compared to what is seen on Earth. Mount Sharp itself is beyond these peaks, not visible because it is about 26 miles away and blocked by these lower mountains.

Since landing on Mars a dozen years ago, the rover has traveled 20 miles and climbed about 2,500 feet. Getting to the top of Mount Sharp will therefore probably take more than one or two decades more of travel.

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A channel of ice, water, or lava?

12:31 pm

A channel of ice, water, or lava?
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows one small section of a Martian canyon approximate 750 miles long and dubbed Elysium Fossae.

The canyon walls at this spot rise about 3,300 to 3,800 feet from the canyon floor. The canyon itself is thought to be what geologists call a graben, initially formed when the ground was pulled apart to form a large fissure.

That’s what happened at this location, at least to start. This canyon is on the lower western flank of the giant shield volcano Elysium Mons. The cracks, which radiate out outward from the volcano’s caldera, likely formed when pressure from magma below pushed upward, splitting the surface.

That formation process however does not fully explain everything.
» Read more

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A frozen Martian splash

11:31 am

A frozen Martian splash
Click for original image.

Cool image time! The picture to the right, rotated, cropped, and enhanced to post here, was taken on July 11, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the southeast quadrant of a three-mile-wide unnamed crater that is surrounded on all sides by a dramatic but frozen splash apron of material, created when this impact occurred.

The rim rises between 200 to 400 feet from the surrounding plains, while the crater floor drops 700 feet to sit below those plains by 300 to 500 feet. In other words, that splash apron contains the material that was thrown up when the bolide drilled into the plain at impact, leaving behind this deep hole.

Why such a dramatic splash apron? Its existence suggests that the ground here was muddy, with a lot of water ice likely present. The location and wider context helps confirm this guess.
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Due to thruster problem, the Mercury orbiter BepiColombo will arrive at Mercury almost one year late

9:05 am

The joint ESA and JAXA Mercury mission BepiColombo will now reach its destination eleven months late because its ion electric thrusters are producing less thrust than expected.

The spacecraft is actually made up of two orbiters, one built by the European Space Agency (ESA) and the second built by Japan’s space agency JAXA. During launch and the journey to Mercury each is attached to a third spacecraft called the Mercury Transfer Module (MTM), which has the large electric ion thrusters used for making the mid-course corrections prior to and after each fly-by of the Earth (once), Venus (twice), and Mercury (six) before finally entering orbit around Mercury. It has already completed the Earth, Venus and three Mercury fly-bys.

In April 2024 engineers discovered that during a mid-course correction on April 26st the MTM’s thrusters failed to produce the desired thrust.

Engineers identified unexpected electric currents between MTM’s solar array and the unit responsible for extracting power and distributing it to the rest of the spacecraft. Onboard data imply that this is resulting in less power available for electric propulsion. ESA’s BepiColombo Mission Manager, Santa Martinez explains: “Following months of investigations, we have concluded that MTM’s electric thrusters will remain operating below the minimum thrust required for an insertion into orbit around Mercury in December 2025.”

In order not to lose the mission entirely, the science team has come up with a new trajectory that will have it fly past Mercury on its fourth fly-by on September 4, 2024 only 103 miles above the surface, 22 miles closer than originally planned. This will give it a larger slingshot speed boost to help make up for the under-powered thrusters. It will then make its planned fifth and sixth Mercury fly-bys in December ’24 and January ’25, the adjusted route having it arrive in Mercury orbit eleven months later than planned, in November 2026.

This new plan however means that the pictures taken this week during the Mercury fly-by will provide some nice high resolution details, far better than those produced by the earlier fly-bys.

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A cliff of ice on Mars

12:56 pm

A cliff of ice on Mars
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken on April 10, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the southern nose of a large plateau located in the deep south of Mars, at 63 degrees south latitude. This cliff is only about 20-25 feet high, but within that small distance orbital imagery as revealed what appears to be an underground layer of ice. When this photo was released in late June, it came with a short caption, which noted:

On these steep scarps, ice can still be seen on the south facing walls of the scarp towards the end of the Southern Hemisphere’s winter.

Note the white sections on that cliff wall, both inside and outside the color strip. The surrounding orange suggests dust and sand. This photo suggests that during the dark winter underground ice leaches out on these slopes, and is then sublimated away when the Sun returns in the spring. Since the south-facing walls remain in shadow the longest, the ice there lasts the longest, leaving behind these patches we see now.

It is also possible that this is not water ice and there is no underground ice layer. Instead, this might be the last leftover of the dry ice mantle that falls as snow and covers all of the Martian high latitudes during the winter, and then sublimates away come spring.
» Read more

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Changing Martian slope streaks

12:27 pm

Changing slope streaks on Mars
Click here, here, and here for original images.

Overview map

Time for some cool images from Mars taken over a dozen years! The three pictures above were taken, from left to right, in 2012, 2020, and 2024 and show the same exact Martian terrain. The first two pictures were photographed by the lower resolution context camera on Mars Reconnaissance Orbiter (MRO). The rightmost picture was taken on May 20, 2024 by MRO’s high resolution camera.

The white dot on the overview map to the right marks the location, in the middle of the vast lava flood plains found between Mars’ giant volcanos and north of the Medusae Fossae Formation, the largest volcanic ash deposit on Mars. The 1,200-foot-high mesa pictured above, its peak indicated by the red dot, is part of a group of such mesas that either represent the peaks of a mountain range now mostly buried by lava, or volcanic vents pushed up when those eruptions were occurring more than a billion years ago.

The focus of these pictures however is not volcanism, but the numerous slope streaks seen on the mesa slopes. Note how the 2012 earliest streaks are still visible in 2024, but have faded. Note also how there appears to have been no new streaks since 2020.

Slope streaks are a geological feature unique to Mars that at the moment remain unexplained. At first glance they appear to be a landslide of some kind, but years of orbital study has shown they do not change the topography at all, they never have debris piles at their base, and the streaks even sometimes actually flow up and over small rises in the slopes. They occur randomly throughout the year, and as seen above, over time fade.

Recent research has suggested their formation is related to dust avalanches triggered by dust storms, conclusions that are strengthened by the fact that slope streaks are generally found on dusty slopes, which in this case makes sense as the location is in the dry Martian tropics. That these dust avalanches do not change the topography at all, merely staining it, while sometimes actually flowing up and over rises, illustrates how Mars’ one-third gravity and thin, cold atmosphere makes things happen that are impossible on Earth.

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Evidence of Martian near-surface ice in an unusual location

11:48 am

Evidence of Martian near-surface ice in an unusual location
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 27, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled merely as a terrain sample, it was likely taken not as part of any specific research request, but to fill a gap in the camera’s picture-taking schedule so as to maintain its proper temperature.

The picture however shows features that help confirm earlier research into the near-surface ice believed to permeate Mars’ middle latitudes. The knobby flat terrain both inside and outside of the crater resembles what scientists have labeled “brain terrain”, an as-yet unexplained geological feature unique to Mars and usually associated with near-surface ice and the glacial features found above 30 degrees latitude.

This 1.4-mile-wide unnamed crater is located at 40 degrees north latitude, so expecting near-surface ice or glacial features here is not unreasonable. The location however is different for other reasons, that make this data more intriguing.
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First high resolution images released from Juice’s fly-by of the Earth & Moon

9:34 am

Juice's high resolution view of the Moon
Click for original image.

The Italian science team that runs the high resolution camera on the asteroid probe Juice have now released that camera’s first images, taken to test its operation during the spacecraft’s close fly-by of both the Moon and then the Earth a week ago.

The picture to the right, cropped, reduced, and sharpened to post here, shows the Moon’s surface during that close fly-by, which got within 435 miles. The camera is dubbed Janus, and was developed by Italy and operated by the Italian National Institute for Astrophysics.

JANUS will study global, regional and local features and processes on the moons, as well as map the clouds of Jupiter. It will have a resolution up to 2.4 m per pixel on Ganymede and about 10 km per pixel at Jupiter.

The main aim of JANUS’s observations during the lunar-Earth flyby was to evaluate how well the instrument is performing, not to make scientific measurements. For this reason, JANUS took images with various camera settings and time intervals – a bit like if you’re going out to test a DSLR camera for the first time. In some cases, researchers intentionally ‘blurred’ the images so that they can test out resolution recovery algorithms. In other cases, they partially saturated the image to study the effects induced on the unsaturated areas.

As can be seen by the sample image above, the test images appear to have demonstrated that Janus will function as planned when Juice arrives in orbit around Jupiter in 2031 in order to study that gas giant’s upper atmosphere as well as its larger icy moons, Ganymede, Calisto, and Europa.

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Finding beauty on Mars in all the strange places

12:08 pm

Overview map

Beauty on Mars
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken on May 23, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The white dot in the inset of the overview map above indicates the location on Mars, smack dab in the middle of the 2,000-mile-long mid-latitude strip that I call glacier country, because practically every close-up image of this region shows glacial features.

This picture is no exception. The arrows in the inset show the downhill grade, falling about 1,700 feet across the entire inset. That grade is a reflection of the transition that takes place in this glacier country from the cratered southern highlands to the northern lowland plains.

I decided to crop the image at full resolution — showing only a tiny portion — because to my eye these curving linear grooves, produced naturally as Mars’ climate cycles cause glaciers to shrink and then grow repeatedly so that each cycle lays down a new line while squeezing the previous lines, are almost like a work of art. This might be nothing more than a glacier on an alien planet, but nature has caused it to form a very beautiful picture.

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Chinese scientists find method to extract water from Chang’e-5 lunar samples

12:04 pm

Proposed concept for extracting water from lunar regoilth
Proposed concept for extracting water from
lunar regoilth

Chinese scientists have found that by heating Chang’e-5 lunar samples to 1,700 degrees Fahrenheit it is possible to extract a significant amount of water. From the paper’s abstract:

FeO and Fe2O3 are lunar minerals containing Fe oxides. Hydrogen (H) retained in lunar minerals from the solar wind can be used to produce water. The results of this study reveal that 51–76 mg of H2O can be generated from 1 g of LR [lunar regolith] after melting at temperatures above 1200 K. This amount is ∼10,000 times the naturally occurring hydroxyl (OH) and H2O on the Moon. … Our findings suggest that the hydrogen retained in LR is a significant resource for obtaining H2O on the Moon, which are helpful for establishing scientific research station on the Moon.

A video in Chinese (hat tip BtB’s stringer Jay) that describes this research can be found here. (If any of my readers understands Chinese and can provide a translation of this video’s narration, I would be very grateful.) It includes an artist’s rendering (screen capture to the right) showing how such a system on the Moon could work to extract water from the soil. Sunlight would be focused by a lensed mirror into a glass-domed container, heating the ground. The water would evaporate, condense on the glass and be sucked into a tube that would transfer it to a water tank.

This design is of course very simple and preliminary. According to Jay, “They need to heat the soil to 1000℃ (1832°F) to get the iron oxide in the lunar soil to split, the oxygen combines with hydrogen to make water and iron (melting point of iron is about 1500℃). You will need a nuclear reactor to produce that much power for an inductive furnace to get that hot. Doing the calculation, it would take about 245kw to heat up a metric ton of dirt in one hour to a 1000℃ degrees. It could be done slower over 24 hours at 10kw.”

Despite the technical difficulties getting such equipment operational on the Moon, that this research suggests water can be produced practically anywhere on the lunar surface is signficant. It suggests that even if no easily accessible water ice is found in the permanently shadowed craters at the poles, lunar bases still have viable options for obtaining water, and they don’t have even be at the poles.

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The massive scale of Mars’ biggest canyon

12:24 pm

Overview map

The south rim of Valles Marineris
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on May 24, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled merely a “terrain sample” by the camera team, it was likely taken not as part of any particular research project, but to fill a gap in the picture-taking schedule in order to maintain the camera’s proper temperature.

When the camera team needs to do this, they try to pick interesting targets within the required timeframe. Sometimes they succeed, sometimes not. In today’s example, they succeeded quite well. As shown by the overview map above, this picture captures (as indicated by the rectangle) the top of the southern rim of Valles Marineris, the biggest canyon on Mars and quite possibly the biggest in the entire solar system.

For scale, the drop from the rim to the low point in this picture is about 9,000 feet. That’s a 1,000 feet more than the drop from the north rim of the Grand Canyon to the canyon bottom at the Colorado River. In Valles Marineris however our descent has barely begun. To get to the bottom of the southern canyon here you still need to drop 15,000 more feet, for a total descent of 24,000 feet, an elevation change similar to most of the mountains in the Himalayas.

Nor are you yet at the bottom. If you climb over the ridge of 18,000-foot-high mountains that bisect Valles Marineris at this point, you can drop down even further, to a depth 31,000 feet below the southern rim.

Mount Everest is just over 29,000 feet high, which means if placed inside Valles Marineris is peak would still sit 2,000 feet below the rim.

The photo itself highlights part of the erosion process that formed Valles Marineris. This is the dry tropics, so no water was involved in shaping this terrain for many eons. Instead, what appear to be flows within the hollows is alluvial fill, material that over time breaks off and rolls downhill, filling the slopes below. Erosion will grind this material into smaller particles, so given enough time it flows almost like sand.

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Pragyan data confirms theory that the Moon’s surface was once largely covered with molten lava oceans

10:03 am


Vikram as seen by Lunar Reconnaissance Orbiter.
Click for interactive map. To see the original
image, go here.

Data from India’s Pragyan lunar rover that landed in the high southern latitudes of the Moon in August 2023 has now confirmed the theory that the Moon’s surface was once largely covered with molten lava oceans.

Santosh Vadawale, an X-ray astronomer at the Physical Research Laboratory in Ahmedabad, India, and his colleagues analysed radiation data collected by the APXS [one of Pragyan’s instruments], and used this information to identify the elements in the regolith and their relative abundances, which, in turn, revealed the soil’s mineral composition. The team found that all 23 samples comprised mainly ferroan anorthosite, a mineral that is common on the Moon. The results were reported in Nature today.

“It’s sort of what we expected to be there based on orbital data, but the ground truth is always really good to get,” says Lindy Elkins-Tanton, a planetary scientist at Arizona State University in Tempe.

Previous landers obtained similar results. However, the Chandrayaan-3 samples are the first from the subpolar region: previous landers visited equatorial and mid-latitude zones. Together, this suggests that the composition of the regolith is uniform across the Moon’s surface.

These results are no surprise, but they confirm the global nature of the Moon’s early molten history. More important, they demonstrate that India now has the capability to send landers and rovers to other planets that are also capable of doing real research.

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What the heck caused these cones to align on Mars?

2:48 pm

Another
Click for original image.

Time for another “What the heck?” cool image! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 23, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team labels as “longitudinally aligned cones”.

To my eye the cones visibile in this picture seem more aligned latitudinally, to the east-west, instead of longitudinally, north-south, but the larger view in the inset on the overview map below shows that on a larger scale, the cones do appear aligned in a north-south direction.

Either way, this is one of those photos from Mars orbit that leaves me entirely baffled. The cones and the flow feature that cuts across the middle of the image might be either volcanic or glacial, but it is beyond my pay grade to explain what caused this patch of aligned cones.
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Mining Mars

12:08 pm

Mining Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 22, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The picture’s focus of study is the bright strip running diagonally across the center, which the scientists label as a “linear feature exposure of infrared-bright material.”

This bright strip with all the swirls of alternating light and dark terrain is a fissure about 80 feet deep. What is interesting is that the parallel bright features to the north and south are actually ridges, not depressions, even though there appears to be some resemblance between them all. (Note that the patches of very thin parallel lines are likely ripple dunes sitting on top of the topography.)

So, what created this fissure? And why is its inner surface so strange? As is usually the case, a wider look provides some clues.
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Martian gullies flowing down to a Martian river of ice

11:30 am

Gullies on cliff wall
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on May 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The scientists label this as “gullies previously identified in the walls of Harmakhis Vallis.” The gullies are obvious, the series of erosion features on the cliff wall. The cliff itself drops about 2,800 feet from the rim to the floor, and also appears to have internal horizontal layers that the gullies cut through.

What causes the gullies? Planetary scientists have a number of theories, none of which appear to explain the gullies everywhere on the Martian surface. They all appear in the mid-latitudes, where the most glaciers on Mars are found, and appear to be related to ice or frost freeze-thaw processes, with some gullies actually very ancient and formed when the planet’s rotational tilt was significantly different.
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Buried peaks in a sea of Martian sand

12:46 pm

Buried peaks in a sea of sand
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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on April 13, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the MRO science team labels as “streamlined features”, though that doesn’t seem to me to be the best description.

Granted, the prevailing winds, from the northeast to the southwest, appear to pushing the sand dune fields to the southwest. The dark line — created recently by a dust devil — indicates the wind direction. The mesas, from 100 to 200 feet high, do not however appear very streamlined. Instead, they simply look like they are poking up through this sea of sand and dunes, with the wind able over time to successfully push that sand uphill a hundred-plus feet into the saddle between the mesas.

The overview map below provides some context and possibly an explanation, though not a very conclusive one.
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The strange carbon dioxide ice cap of Mars’ south pole

12:33 pm

The strange carbon dioxide cap of Mars
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken on July 1, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The image is labeled simply as a “terrain sample,” which usually means it was taken not as part of any specific research project but to fill a gap in the picture-taking schedule in order to maintain the camera’s proper temperate. When the camera team needs to do this, they try to picture interesting features availabe at that time slot. Sometimes the image is boring. Sometimes it is surprisingly interesting.

In this case the picture is the latter, and certainly quite alien. The curly parallel dark lines appear to be grooves, and seem to have ripple dunes within them, as if the only dust here got trapped in those low spots. It is also possible that the dunes are frozen and ancient, and are only being revealed as the top layer in each groove goes away.

What could possibly explain what we are looking at? The overview map below gives only a clue.
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