Crazy swirling Martian landscape

Crazy swirling Martian landscape
Click for original image.

Cool image time! The picture to the right, cropped, reduced, sharpened, and annotated to post here, was taken on July 1, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labels this “Contacts between Likely Sulfates and Chaos Blocks.” That contact I have indicated with the dotted line. To the west the lighter terrain is likely the sulfate-bearing unit, similar to the sulfate-bearing unit that Curiosity has been traversing on Mount Sharp for the past year or so.

To the east are the chaos blocks, but I think that description is wholly inadequate. In truth, I haven’t the faintest idea how this terrain got to be the way it is. It is evident that a lot of dust and sand has gotten trapped in the hollows, leaving behind ripple dunes in some places, but why the higher ridges swirl and curve about as they do is utterly baffling.
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Monitoring gullies on Mars for changes

Overview map

Monitoring gullies on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on June 29, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The scientists label the picture simply as “gully monitoring,” with an apparent goal of looking to see if this gully has changed since MRO took the first high resolution image two years previously. In the interim this terrain went from Martian spring, through summer and winter, and has now returned to spring.

As far as I can tell, no changes are visible, but then I am not using the highest resolution data available. Small changes might be detectable in the highest resolution using good detection software. Overall, the gully drops about 3,000 feet.

The white dot in the overview map above marks the location, on the southwest interior rim of an unnamed 30-mile wide crater. This region in the Martian cratered highlands was featured in a four part cool image series I did back 2023 (here, here, here, and here), with this as my conclusion:

Overall, our short survey of the southern cratered highlands suggests that the glacial material and ice found in the southern mid-latitudes affects the Martian surface differently than in the northern lowland plains. In the north the craters and the surrounding terrain often appear blobby, as if the ice is close to the surface and also a dominant component of the ground. Impacts therefore cause significant soft melt features, with craters often heavily distorted. Similarly, there is evidence of the existence of past mud volcanoes that once spewed water and mud from below ground.

In the south however the surface is at a higher elevation, and it appears the ice layer is deeper underground. Thus, it appears the ground is more firm, and the only obvious evidence of an underground layer of ice is revealed when sublimation and the subsequent erosion produce these large pits inside craters.

In the case of this crater, a small impact on its interior southwest slope apparently caused that underground layer of ice to melt temporarily and flow downhill, leaving behind the gully and flow features we see today. Based on the two MRO pictures taken a full Martian year apart, it appears the feature is generally stable and thus likely old, left over from that impact. If things are changing seasonally they are doing so in small amounts and slowly.

A puzzling striped rock on Mars

A striped rock on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on September 13, 2024 by one of the high resolution cameras on the Mars rover Perseverance. The rock’s striped nature makes it unique, unlike any feature spotted by any rover previously. From an update today:

The science team thinks that this rock has a texture unlike any seen in Jezero Crater before, and perhaps all of Mars. Our knowledge of its chemical composition is limited, but early interpretations are that igneous and/or metamorphic processes could have created its stripes. Since Freya Castle [the name the science team gave the rock] is a loose stone that is clearly different from the underlying bedrock, it has likely arrived here from someplace else, perhaps having rolled downhill from a source higher up. This possibility has us excited, and we hope that as we continue to drive uphill, Perseverance will encounter an outcrop of this new rock type so that more detailed measurements can be acquired.

Without doubt the rock’s rounded surface suggests it was ground smooth by either water or ice. That surface certainly resembles glacial cobble seen across the northeast of the U.S. where ice glaciers once covered the entire landscape. The rock also resembles river cobble, smoothed by flowing water.

The stripes however suggest that prior to its being smoothed, this rock underwent a much more complex geological process, whereby two different materials were intermixed and squeezed together.

Layered mesas in Martian chaos

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.
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Webb takes an infrared look at a galaxy looked at by Hubble

Comparing Hubble with Webb
For original images go here and here.

Cool image time! The bottom picture on the right, cropped to post here, is a just released false color infrared image of the galaxy Arp 107, taken by the Webb Space Telescope. The picture at the top is a previously released optical image taken by the Hubble Space Telescope and featured as a cool image back in September 2023. The Hubble image was taken as part of a survey project to photograph the entire Arp catalog of 338 “peculiar galaxies,” put together by astronomer Halton Arp in 1966. In this case Arp 107 is peculiar because it is actually two galaxies in the process of merging. It is also peculiar because the galaxy on the left has an active galactic nuclei (AGN), where a supermassive black hole is sucking up material and thus emitting a lot of energy.

The Webb infrared image was taken to supplement that optical image. The blue spiral arms indicate dust and star-forming regions. The bright orange object in the center of the galaxy is that AGN, clearly defined by Webb’s infrared camera.

When I posted the Hubble image in 2023, I noted that “if you ignore the blue whorls of the left galaxy, the two bright cores of these merging galaxies are about the same size.” In the Webb image the two cores still appear about the same size, but in the infrared they produce emissions in decidedly different wavelengths, as shown by the different false colors of orange and blue. The core of the galaxy on the right is dust filled and forming stars, while the core of the left galaxy appears to have less dust with all of its emissions resulting from the energy produced by the material being pulled into the supermassive black hole.

The universe is very active and changing, but to understand that process we humans have to look at everything across the entire electromagnetic spectrum, not just in the optical wavelengths our eyes see.

Some new “What the heck?” geology on Mars

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.
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Intuitive Machines targeting January 2025 for launch of its next lunar lander

The landers either at or targeting the Moon's south pole
The landers either at or targeting the Moon’s south pole

The company Intuitive Machines is now aiming to launch its second Nova-C lunar lander, dubbed Athena, during a January 1-5, 2025 launch window.

The landing site is indicated on the map to the right, on the rim of Shackleton crater and almost on top of the south pole. While Chang’e-7 is targeting the same crater rim, it is not scheduled for launch until 2026.

The lander will not only include a drill for studying the surface below it, it will release a small secondary payload, the Micro-Nova Hopper, which will hopefully hop down into the permanently shadowed craters nearby.

The launch will also carry a lunar orbiter, dubbed Lunar Trailblazar, which will not only do spectroscopy of the lunar surface, looking for water, it will also be used as a communications relay satellite with Athena. That orbiter, designed to demonstrate the ability to build a smallsat at low cost, was previously threatened with cancellation because its builder, Lockheed Martin, went way over budget.

New gravity map of Mars released

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.

A fluted mesa on Mars

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

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.

A crack on Mars more than 600 miles long

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.
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Musk: First unmanned Mars Starship targeting a ’26 launch

The prime and secondary Martian landing sites for Starship

According to a tweet yesterday by Elon Musk, SpaceX is aiming for a 2026 launch of its first unmanned Starship to Mars.

The first Starships to Mars will launch in 2 years when the next Earth-Mars transfer window opens. These will be uncrewed to test the reliability of landing intact on Mars. If those landings go well, then the first crewed flights to Mars will be in 4 years.

Flight rate will grow exponentially from there, with the goal of building a self-sustaining city in about 20 years.

The graphic to the right indicates the planned landing zone, with the four red dots the four prime locations. Three of the four are very flat, though they also appear to have a lot of very near-surface ice, accessible simply by digging a shovel into the ground. Attempting to land at any will definitely test Statship’s ability to land on Mars intact. A global map of Mars is shown below, showing the location of this landing zone. The map shows where researchers believe the saltiest water on Mars would be. According to this data, in the Starship landing zone some of that near-surface ice will turn to liquid brine a little less than one percent of each year. Otherwise it will be more easily processed for drinking and fuel.

As always with these ambitious predictions, Musk is aiming high, with the likelihood that this first mission will not make that ’26 date. At the same time, he is making it very clear that a first attempt will certainly happen by ’28.

I also think the timing of this announcement is intriguing, coming one day after NASA was forced to cancel the launch in October of two Mars orbiters because it could not be certain Blue Origin would have the New Glenn rocket ready on time. Musk’s response is to say that SpaceX is now about to begin regularly privately funded and privately built missions to Mars, on a schedule, essentially asking: “Which company would you choose to do things in space?”
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NASA cancels launch of its two Escapade Mars Orbiters due to Blue Origin delays

After reviewing the status of launch preparations by Blue Origin of its New Glenn rocket, NASA today decided to cancel the launch because it appeared that Blue Origin would not be able to meet the October 13-21 launch window for sending the agency’s two Escapade orbiters to Mars.

NASA announced Friday it will not fuel the two ESCAPADE (Escape and Plasma Acceleration and Dynamics Explorers) spacecraft at this time, foregoing the mission’s upcoming October launch window. While future launch opportunities are under review, the next possible earliest launch date is spring 2025.

The agency’s decision to stand down was based on a review of launch preparations and discussions with Blue Origin, the Federal Aviation Administration, and Space Launch Delta 45 Range Safety Organization, as well as NASA’s Launch Services Program and Science Mission Directorate. The decision was made to avoid significant cost, schedule, and technical challenges associated with potentially removing fuel from the spacecraft in the event of a launch delay, which could be caused by a number of factors.

The press release of course is vague about why the launch has been canceled, but the reasons are obvious if you have been paying attention. Though Blue Origin has clearly been making progress towards the first launch of New Glenn, recent reports suggested strongly that it would be impossible for it to assemble the rocket, integrate the two orbiters, and get everything on the launchpad on time.

Rocket Lab, which built the orbiters, of course fully supported the decision, though that company very much wanted it to fly now to demonstrate its ability to make low cost smallsat planetary probes.

This failure of Blue Origin to meet this deadline speaks poorly of the company. To serve the satellite and especially the planetary research community rocket companies must be able to launch on schedule and on time. Blue Origin has failed to do so in this case. It appears Jeff Bezos needs to ramp up the pressure on his moribund company to finally get it to perform in the manner he desires, as described by Bezos himself recently.

Curiosity takes another look south into Gediz Vallis

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.

A channel of ice, water, or lava?

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.
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A frozen Martian splash

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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A cliff of ice on Mars

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.
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Changing Martian slope streaks

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.

Evidence of Martian near-surface ice in an unusual location

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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A real whirlpool in space

A real whirlpool in space
Click for original image.
Cool image time! The picture above, cropped to post here, was taken by the Hubble Space Telescope as part of a survey of nearby galaxies that have what astronomers call an Active Galactic Nuclei (AGN), because the supermassive black hole at the center is devouring nearby material at a great rate and thus producing high energy emissions as it does so.

Many active galaxies are known to astronomers at vast distances from Earth, thanks to the great brightness of their nuclei highlighting them next to other, dimmer galaxies. At 128 million light-years from Earth, UGC 3478 is positively neighbourly to us. The data used to make this image comes from a Hubble survey of nearby powerful AGNs found in relatively high-energy X-rays, like this one, which it is hoped can help astronomers to understand how the galaxies interact with the supermassive black holes at their hearts.

The bottom line is that this spiral galaxy literally is a whirlpool, the entire galaxy spiralling down into that massive black hole in its center. One cannot help wondering why such galaxies don’t end up eventually getting completely swallowed by that black hole.

Or maybe they do, and we don’t see such things because all that is left is a supermassive black hole that emits no light or energy at all, a dark silent ghost traveling between the galaxies unseen and undetectable.

Finding beauty on Mars in all the strange places

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.

The massive scale of Mars’ biggest canyon

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.

The North Star has spots!

The spoted surface of Polaris
Click for original image.

Astronomers using an array of six ground-based telescopes have obtained best new data of Polaris, the North Star, including the first rough image of its surface, and discovered sunspots on its surface.

You can read the paper here [pdf]. The image to the right, taken from figure 4 of the paper, shows the surface as seen by the telescopes over two nights in April 2021. Polaris is what astronomers call a Cepheid variable star, which changes brightness on a very precise schedule as its diameter grows and shrinks. In the case of Polaris, that variation is four days long. The star’s brightness itself varies only slightly, and over the decades has even at times appeared to cease its variations.

As the true brightness of Cepheids is very predictable based on their pulse rate, these stars are one of the main tools astronomers use to determine distances to other galaxies. Knowing more about them thus has great importance to cosmological research.

The orbital motion showed that Polaris has a mass five times larger than that of the Sun. The images of Polaris showed that it has a diameter 46 times the size of the Sun.

The biggest surprise was the appearance of Polaris in close-up images. The CHARA observations provided the first glimpse of what the surface of a Cepheid variable looks like. “The CHARA images revealed large bright and dark spots on the surface of Polaris that changed over time,” said Gail Schaefer, director of the CHARA Array. The presence of spots and the rotation of the star might be linked to a 120-day variation in measured velocity.

The researchers plan to take regular images again of Polaris to better track the changes to its surface.

What the heck caused these cones to align on Mars?

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

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

Gullies on cliff wall
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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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Webb data suggests the possibility of ice and hydrated minerals on surface of Psyche

Using the Webb Space Telescope, astronomers have detected evidence of hydrated minerals and even possibly a very tiny amount of water ice on the surface of the metal asteroid Psyche.

The Webb data point to hydroxyl and perhaps water on Psyche’s surface. The hydrated minerals could result from external sources, including impactors. If the hydration is native or endogenous, then Psyche may have a different evolutionary history than current models suggest. “Asteroids are leftovers from the planetary formation process, so their compositions vary depending on where they formed in the solar nebula,” said SwRI’s Dr. Anicia Arredondo, another co-author. “Hydration that is endogenous could suggest that Psyche is not the remnant core of a protoplanet. Instead, it could suggest that Psyche originated beyond the ‘snow line,’ the minimum distance from the Sun where protoplanetary disc temperatures are low enough for volatile compounds to condense into solids, before migrating to the outer main belt.”

However, the paper found the variability in the strength of the hydration features across the observations implies a heterogeneous distribution of hydrated minerals. This variability suggests a complex surface history that could be explained by impacts from carbonaceous chondrite asteroids thought to be very hydrated.

You can read the research paper here [pdf]. The actual amount of water possible is at most 39 parts per million and is also an order of magnitude lower than that found on the Moon, which strongly suggests that it comes from outside sources, such as impacts from other asteroids, not from the inherent geological history of Psyche itself.

The uncertainties of this research, which are large, which should be resolved when the probe Psyche, launched last year, reaches the asteroid Psyche in August 2029.

Buried peaks in a sea of Martian sand

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

The strange carbon dioxide cap of Mars
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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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A galaxy with a ring

A galaxy with a ring
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Cool image time! The photo to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope, and appears part of a long term survey of nearby ringed galaxies. From the caption:

MCG+07-07-072 has quite an unusual shape, for a spiral galaxy, with thin arms emerging from the ends of its barred core to draw a near-circle around its disc. It is classified, using a common extension of the basic Hubble scheme, as an SBc(r) galaxy: the c denotes that its two spiral arms are loosely wound, each only performing a half-turn around the galaxy, and the (r) is for the ring-like structure they create. Rings in galaxies come in quite a few forms, from merely uncommon, to rare and astrophysically important!

Lenticular galaxies are a type that sit between elliptical and spiral galaxies. They feature a large disc, unlike an elliptical galaxy, but lack any spiral arms. Lenticular means lens-shaped, and these galaxies often feature ring-like shapes in their discs. Meanwhile, the classification of “ring galaxy” is reserved for peculiar galaxies with a round ring of gas and star formation, much like spiral arms look, but completely disconnected from the galactic nucleus – or even without any visible nucleus! They’re thought to be formed in galactic collisions.

This galaxy is about 320 million light years away, and is also known as Abell 426. Though astronomers think that these various shapes of galaxies, from barred to lenticular to ringed, are formed from a variety of galactic collusions and interactions with each galaxy’s nucleus, that remains nothing more than an educated guess. The complexity of galaxy evolution, involving billions of years and millions of stars, is barely in its infancy, and requires a lot of assumptions because our observations only involves a mere nanosecond in that grand history.

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