The foot of a Martian glacier

The foot of a Martian glacier
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on February 18, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as the “terminus of possible glacier-like feature.” That feature is at the lower left, at the point where glacier-like material appears to be flowing out of the channel from the northeast but then ending in an area of rough fingers.

That this looks exactly like a glacier does not guarantee that it is one, which is why the scientists insert the word “possible.” Nonetheless, the geology resembles that of a glacier, from the parallel lines along its length as well as its existence inside this channel. The location is also at 49 degrees south latitude, well within the mid-latitude strips on Mars where scientists believe many such glaciers exist.

The overview map below adds further weight to this conclusion. It also suggests that there are even more glaciers on Mars than research up to now has suggested.
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The taffy terrain in Mars’ death valley

Taffy terrain in Hellas Basin on Mars

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on February 21, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled “banded terrain and layering,” it actually is a good example of “taffy terrain,” a weird Martian geological formation unique to the Red Planet that scientists as yet don’t quite understand. This 2014 paper only says this:

The apparent sensitivity to local topography and preference for concentrating in localized depressions is compatible with deformation as a viscous fluid. In addition, the bands display clear signs of degradation and slumping at their margins along with a suite of other features that include fractured mounds, polygonal cracks at variable size-scales, and knobby/hummocky textures. Together, these features suggest an ice-rich composition for at least the upper layers of the terrain, which is currently being heavily modified through loss of ice and intense weathering, possibly by wind.

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Complex ridged terrain in ancient Martian crater

Complex ridges in an ancient Martian crater
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken on January 16, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Because an electronic unit for one of this camera’s filters has failed, causing a blank strip in the image center, I have filled in that gap using an MRO context camera image taken October 31, 2015.

The scientists describe this geology as “ridged terrain.” What I see is a surface that was like wet plaster once, and then a giant finger touched it and pulled away quickly, so that as it left some material pulled upward to create random ridges within the depression created by that finger.

These ridges are inside a very very ancient 110-mile-wide crater dubbed Margulis. According to the 2021 poster [pdf] of the scientists who did the first geological mapping of this crater, the crater floor “show remnants of sedimentary materials, suggesting the [crater was] subjected to widespread episodes of resurfacing and denudation.”

Though located in the dry equatorial regions, this ridged terrain suggests it formed suddenly when underground ice sublimated into gas, bursting upward to break the surface when the gas pressure became high enough.
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Patches of volcanic Martian ash covering patches of frozen volcanic dunes

Patches of volcanic Martian ash over frozen volcanic dunes

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on December 24, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

What makes this terrain intriguing are the series of parallel ridges that cover most of the picture, with smaller ridges at right angles filling the hollows between. It appears we are looking at two different sets of dunes, the larger ridges indicating the southeast-to-northwest direction of the prevailing winds, while the smaller ridges in the hollows suggest the wind patterns within the hollows, causing smaller ripple dunes to form at right angles.

Note however the flat patches in the lower left. The material there appears to fill the hollows, covering the dunes. We can tell this by the hollows to the east, which have an almost identical dune pattern. Those flat patches then are likely covering similar dunes, with the patched material either having been blown away to expose the lower dunes, or having been blown here to cover them in patches. That the dunes appear unchanged under this patched material when exposed also suggests strongly that these dunes are hardened into stone, no longer soft sand that can be blown by the wind.
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The Martian view from high on Mount Sharp

The Martian view of mountains
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was downloaded today from left navigation camera on the Mars rover Curiosity.

The image looks to the north from the lower foothills of Mount Sharp. The view is downhill across the floor of Gale Crater. The intermittent dotted red line that weaves between those foothills marks the approximate route that Curiosity took to climb through them to reach this point.

About 20 to 25 miles away the mountainous rim of the crater can be seen dimly. The air is filled with dust, because its is almost the peak of the dust season at Gale Crater, located just south of the Martian equator.

The overview map below provides some further context.
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Martian waves of ridges and cracks

Martian waves of ridges and cracks
Click for original image.

In preparing today’s cool image I initially planned to post an picture taken on December 26, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), as it showed a strange series of ridges that almost resembled waves or ripples on a pond.

In digging into MRO’s context camera archive to get the larger context, however, I immediately switched to the photo on the right, cropped, reduced, and sharpened to post here. Taken on December 17, 2010, it shows a much more mysterious and striking set of geological features than the closer view of the high resolution image, with the wave-shaped ridges on its western half but another set of wave-shaped cracks on its eastern half.

Even more intriguing, the arcs for the ridges curve in the opposite direction from the arcs for the cracks. It is almost as if there were two flows moving in opposite directions, right next to each other.
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Scientists release detailed geological map of the landing site for Europe’s Franklin rover

Low resolution cropped section of map
Click for original image.

Scientists today released a new high resolution and very detailed geological map of the landing site for Europe’s Franklin rover, produced using orbital data from the U.S.’S Mars Reconnaissance Orbiter and Europe’s Trace Gas Orbiter.

A very low resolution version of the map is to the right.

The work was divided into 134 one-square-kilometre areas, so that the [80-person] team could fully cover the estimated landing area. Scientists used a web-based system that allowed everyone to work on the map in parallel. The software was provided by NASA’s Jet Propulsion Laboratory and set up at ESA [European Space Agency]. Data came from the Colour and Stereo Surface Imaging System (CaSSIS) onboard the ExoMars Trace Gas Orbiter and several instruments on NASA’s Mars Reconnaissance Orbiter (MRO), including the HiRISE camera, which returns images from Mars orbit at 25 cm per pixel.

The mapping leads then pieced together the information on all the areas to form a coherent map that shows the geology of the landing site in unprecedented detail. The map includes the main types of bedrock, and structures with distinct shapes like ridges and craters. It even features the material that rests on top, for example blown by the wind, or thrown long distances when meteorites impacted the surface.

The result is the highest resolution map of Oxia Planum yet, created at a scale of 1:25 000, by which every centimetre equals 250 metres on the martian surface. An average drive of 25 to 50 metres a day for Rosalind Franklin would be one to two milimetres on the map.

The team had the extra time to compile this map because the launch of Franklin to Mars was delayed a number of times because of engineering issues and the Ukraine War, which ended the Europe’s partnership with Russia, requiring ESA to find other means to launch and land the rover.

Data from Perseverance suggests the delta in Jezero Crater was formed by a wide variety of different “fluvial” events

Jezero Crater delta
Jezero Crater delta

Using data from the Perseverance rover in Jezero crater, scientists now conclude that the delta that poured through a gap in the crater’s rim was formed by a wide variety of different “fluvial” events, not a steady flow as previously assumed.

From the paper’s conclusions:

The origin of this variability as well as that of the high discharge represented by the boulder conglomerate is still unknown. Realistic hypotheses include seasonal variations due to melting of snow, glacial input with possible episodic surges punctuating more regular fluvial input, or arid climate type of flows with intense storms and related flash floods.

We do not speculate further about the nature of fluvial activity in this study. However, the variability and the presence of high discharge rates have important implications on the lake evolution. Firstly, previous modeling of Jezero delta formation used steady-state discharge rates to estimate the time required to form the delta, an assumption that we can no longer justify according to our observations. Secondly, estimates of discharge rates … may be used as upper limits for some of the peak discharge rates, although the number of flood events is still difficult to determine from the sparse outcrops and the ubiquitous presence of scree.

In other words, the delta was not formed by a single event or a long stream of liquid flowing into the crater to form the lake that scientists believe once filled the crater. Instead, that flow varied, involved numerous distinct and different events over time, and likely included glacial ice transport as well.

Not that this is a surprise, but as always, the closer we get to a planet and the more detailed our data about it, the more complicated we find its nature and origins.

Bursting bubbles of water gas on Mars

Bursting bubbles on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on January 12, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Because of a technical issue that leaves a blank strip down the center of recent high-res MRO images, I have filled in that gap using a MRO context camera photo taken on January 12, 2015. The resolution is much less, but by doing so we can see the ground features as a unit.

What are we looking at? According to the scientists, this picture shows “fresh-looking ruptures,” referring to the broken line of sharp tears inside that meandering canyon that almost resemble a fresh wound in flesh. As this location is at 28 degrees south latitude, it lies on the edge of dry equatorial regions, where orbital images have sometimes found hints of a few remaining buried glaciers that are much more common closer to the poles.

In this case it appears the warmer equatorial climate has acted to heat up the buried ice so that it sublimated into gas. At some point the gas pressure caused the surface to burst, much like bubbles bursting on the surface of a pot of simmering tomato sauce, leaving behind these scars.
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Martian vent or sink?

A Martian vent or sink?
Click for original image.

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

Though the scientists label this image showing “channels”, what I see is either a vent or a sink, with the channels to the south indicating past flows either coming out of the depression or into it. The uncertainty exists because the surface grade in this region is essentially flat. There is a lot of small up and down variations, but overall it is very difficult to determine the general trend, suggesting that when the depression and channels formed the grade was different, and there is no way from this data to determine the angle at that time.

Were the flows that created the channels lava or water or ice? Knowing the grade when these channels formed would help answer this question, but other research now suggests the latter.
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Some more “What the heck?” geology on Mars

What the heck?
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on January 1, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a small part of a region dubbed Iani Chaos, but what this geology shows is way beyond my pay grade.

Why there are those tiny aligned mounds, oriented at right angles to the slope, is not clear at all. Nor is it obvious what created the lighter chaotic terrain at the base of the slope.

The elevation difference between the low and high points is about 400 feet. The slope continues up to the west for another 600 feet to the top of a north-south ridgeline. The patterns here suggest vaguely some flows downhill, such as that widening east-to-west gap, but only vaguely.

The look at the overview map only compounds the mystery.
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Cracking terraces in Valles Marineris

Overview map

Cracking terraces in Valles Marineris
Click for original image.

Inset

Today’s cool image returns us to the truly spectacular terrain found on the floor of West Candor Chasma, one of the giant side canyons that form Valles Marineris, the biggest canyon in the solar system, many times larger than the Grand Canyon on Earth.

The picture to the right, cropped, reduced, and sharpened to post here, was taken on January 5, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). On the overview map above its location is indicated by the red dot in the inset. The two green dots mark previous cool images from August 2022 and February 2024.

All three images show the same wild alternating dark and light terracing, suggesting many sedimentary layers like those seen in our Grand Canyon, but enhanced by the different erosion processes of the thin Martian atmosphere and its one-third Earth gravity.

The second image to the right zooms in on the area indicated by the rectangle. What makes this area doubly interesting are the cracks that appear to cut through the terraces. In the north-south crack it also appears that the terraces are now offset on each side of the crack.

Apparently, some event, likely an earthquake that occurred after the terraces formed, caused the ground to rip apart, with the earth shifting sideways on either side. Though the seismometer on the InSight lander detected no major quakes in this region, this image suggests they have occurred here, sometime in the past.

To give you a sense of scale, the canyon’s nearby rim to the west is about 14,000 higher, making that canyon wall two to three times taller than the walls of the Grand Canyon.

The vast Martian plains of lava

The vast Martian lava fields
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on January 31, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled “Lava Embaying Highlands Ridge”, it shows an alcove along a ridgeline that appears filled with material, in this case solid lava.

If you look closely at the ridgeline, you can see several dark streaks on its southern slopes. These streaks could be one of two unique Martian features that remain unexplained. They could be slope streaks, which occur randomly through the year and fade with time, or recurring slope lineae, which occur seasonally at the same locations. In either case, though the streaks look like avalanches, they don’t change the topography, have no debris piles at their base, and even sometimes flow uphill for short lengths. Though there are a number of theories for their formation, many involving dust, none has been accepted as confirmed.

This location and its lava however are the stars of this picture, for a number of reasons, all revealed by the overview map below.
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Mapping the layered geology of Mars

Mapping the layers on Mars
Click for original image.

Today’s cool image is an update of a previous cool image from July 2021. Then, I posted a captioned high resolution Mars Reconnaissance Orbiter (MRO) photo of the many terraced layers within a 13-mile-wide crater dubbed Jiji and located in Arabia Terra, the largest transition zone between the Red Planet’s northern lowland plains and the southern cratered highlands. At that time the caption noted that research was on-going to see if the same layers could be identified in two other nearby craters, Banes and Sera, and thus use that data to extrapolate the long term geological history of this region on Mars.

Today’s cool image to the right, rotated, cropped, reduced, and enhanced to post here, was taken on January 4, 2024 as part of this research, and shows the layers in 18-mile-wide Sera crater, located only about ten miles to the east of Jiji crater. The highest mesa near the bottom of the picture is about twenty feet high on its southern side, but about 140 feet high to the north. The difference is because the crater floor under the mesa is sloping downward to its lowest point to the north.
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Scientists: Mars’ mysterious slope streaks and seasonal recurring lineae are caused by dust

Massive flow on Mars
A typical Martian slope streak.

On Mars there are two mysterious features that are somewhat similar but entirely unique to the Red Planet, and for years have baffled planetary geologists as to their origins.

One feature is called slope streaks, which appear randomly year-round as either dark or bright streaks on slopes. They resemble avalanches, except that they do not change the topography, have no debris piles at their base, and sometimes travel along that topography, sometimes even going uphill for short distances. Over time these streaks then fade.

The other feature is called recurring slope lineae, because though they look like slope streaks, they are not random but appear seasonally at the same places each year. Lineae are also always dark.

Scientists have proposed many theories to explain both, with most theories involving some form of water process, either the seepage of brine from below or water vapor causing the Martian surface dust to flow, like droplets on a car windshield. None of these theories has been confirmed, or entirely accepted.

Two studies at this week’s 55th annual Lunar and Planetary Science Conference in Texas have both concluded that water is not a factor in the formation of either phenomenon. Instead, both papers propose a much simpler explanation: Wind and blowing dust interact to cause small dust avalanches.
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Lucy’s first encounter with an asteroid produced surprises

Dinkinesh, with Salam

At the 55th annual Lunar and Planetary Science Conference presently being held in Texas, the science team for the Lucy asteroid mission presented their first papers outlining what they learned during the spacecraft’s first asteroid encounter, flying past the main belt asteroid Dinkinesh on November 1, 2023.

To the right is the the best image taken at closest approach, at about 270 miles distance, annotated to include the analysis of Dinkinesh’s shape by scientists. As noted in the summary paper [pdf], the asteroid is about a half mile in diameter, and appears to have an equatorial ridge, similar to the ridges found on the near-Earth rubble-pile asteroids Bennu or Ryugu. Dinkinesh is not a rubble pile, however. Though boulder-strewn, it appears more solid, and even has what the scientists call a longitudinal trough, as indicated in the picture.

The ridge overlays the trough implying that it is the younger of the two structures. However, there is as yet no information to better constrain their relative ages, and thus they could potentially have formed in the same event. Indeed, Dinkinesh’s ridge and trough are likely the result of mass failure and the reaccretion of material, and may both be linked to the formation of Selam.

That flyby had produced one major surprise, the existence of a smaller satellite asteroid orbiting Dinkinesh, now dubbed Selam. It is shown in the lower left, as it appeared from behind the main asteroid as Lucy flew past. A later picture however revealed an even greater surprise.
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There likely is little or no ice in the Moon’s permanently shadowed craters

Shadowcam-LRO mosaic
The floor of Shackleton Crater showing no obvious ice deposits,
as seen by Shadowcam. The black cross marks the south pole.
Click for original image.

This week the 55th annual Lunar and Planetary Science Conference is being held in Texas. The conference was originally established in connection with the Apollo missions to allow scientists to release their Moon research results. It quickly morphed into an annual event covering research from the entire planetary research community.

I have reviewed the abstracts for this year’s meeting, and culled what I think are the most significant new results from the conference, which I will report on in the next few posts.

We begin however with possibly the most important result from the conference, given by the science team for the ShadowCam instrument on South Korea’s Danuri lunar orbiter. That low-light camera was designed to take high resolution pictures of the permanently-shadowed craters of the Moon, to see if there was any visible or obvious ice hidden there. Though the science team presented a number of papers, the summary paper [pdf] by the instrument’s principal investigator, Mark Robinson of Arizona State University, gave the bottom line:

The data so far is finding very little evidence of water ice in these dark regions.
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A Martian tadpole

Overview map

A Martian tadpole
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on December 28, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The white dot on the overview map above marks the location, with the rectangle in the inset marking the area covered by the picture. The science team labels this “inverted features,” a more vague way to describe the feature geologists dub “inverted channels.” The flow of a river or glacier acts to harden and increase the density of the channel bed. Later, the water or ice disappears, leaving just the canyon.

Even later, erosion begins to wear away the surrounding terrain. Because the canyon floor is now harder than that surrounding terrain, that floor is more resistent to erosion, and eventually becomes ridge following the exact same path as the long gone river or glacier.

This is what we have here, with this inverted channel, which is about five miles long, once draining into the deeper eroded valley to the south.

The location is at 38 degrees north latitude and inside the 2,000-mile-long mid-latitude region I dub glacier country, because almost every image shows evidence of glaciers or ice flows on the surface. This picture however is a rare exception. The features in this picture instead appear to be bedrock, something that is rarely seen in the canyons and craters in glacier country. It is beyond my pay grade however to explain why this spot lacks such features. Or it could be the near surface ice here looks so much like bedrock I am misinterpreting the picture.

The strange surface of the perennial dry ice cap at Mars’ south pole

The strange surface of Mars' dry ice cap
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken on January 24, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a region about 180 miles from the south pole of Mars.

This terrain is intriguing because is the pattern of ridges that cover it entirely. I have simply cropped the original image to show these ridges in highest resolution. The full image shows them covering a region much larger than this.

What are we looking at? Because it is near the pole, it is likely that the black splotches are caused by carbon dioxide gas breaking through the winter mantle of dry ice that covers the poles during the winter months and then sublimates away, from the bottom, each spring. As the dry ice turns to CO2 gas that gas is trapped, until it can find a weak spot in the overlying mantle. When the pressure builds enough, the mantle breaks, the gas escapes, and as it does so it deposits the dark dust around the breakage. That dust fades as the mantle disappears.

Sounds good, eh? Not so fast.
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The really really strange landscape of Cydonia on Mars

Some really strange terrain on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on January 3, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what the camera team describes merely as “landforms.”

In truth, these features, as well as almost everything in the surrounding terrain beyond the edge of this picture, are possibly the weirdest geological features on Mars. The two mounds, no more than fifteen feet high at the most, resemble pimples. The rough ground to the north actually appears to be some flow that worked its way around the mounds, as indicated by the arrows. The crack to the southeast of the two mounds appears to be an extension of a fault line that cuts through the center of the larger mound, suggesting the mound is some form of eruption belching out of that fissure.

That the latitude is 42 degrees north, these weird features all suggest some form of ice-based volcanic activity, because the ground here is probably impregnated with ice.

As for the bridge connecting the two mounds, who knows what caused it?
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A Martian cliff of ash, flushed by wind

A Martian cliff of ash flushed by wind
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on December 27, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Described merely as an “exposed scarp” by the science team, this cliff edge is actually much more.

First some basic details. The elevation drop from the plateau down to the base of this cliff is about a thousand feet. The material that forms this plateau, scarp, and its base is all volcanic ash. The thicker sections of ash has caused its lower levels to compress, harden into a kind of sandstone. Near the surface however it is more friable, and like sandstone can break apart somewhat more easily.

The prevailing winds at this site are generally blowing to the south, but beginning to turn to the east, which explains the northwest to southeast orientation of the features.

The best analogy I can come up with to explain the erosion of this scarp is as follows: Imagine a deposit of dry mud a few inches thick on pavement. Take a leaf blower and blow at it hard, always in one direction. Eventually the outer edge will break up and blow away, leaving a sharp edge, that will also retreat with time as the wind continues to blow.

Here the winds are eroding that cliff, causing periodic avalanches which dissolve into sand that then blows away, leaving no debris pile at the base of the cliff. The ridges indicate harder material, that breaks away last, which is why there are some ridgelines extending outward from the scarp in line with these ridges. At the same time, these ridges of harder ash still break up with time, as some are cut off suddenly at the cliff edge.
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A recent volcanic eruption on Mars?

A recent volcanic eruption on Mars?
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on December 16, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team labels the two darkened patches in the picture “plume-like features,” suggesting that the dark material was eruptive material thrown out from the depressions in a volcanic venting, that then settled on the nearby surrounding terrain.

Is that a correct interpretation? It is certainly strengthened by a different feature located about 550 miles to the northwest that looks almost the same. There, researchers theorize that the dark material surrounding a surface fissure was caused by a small volcanic event that occurred somewhere between 50,000 to 210,000 years ago. For that other location, scientists concluded as follows:

After careful comparison of this symmetrical dark feature with other dark wind-caused streaks in this region, the scientists concluded that it was not caused by wind, but is the remains of a relatively recent volcanic eruption that laid down a thin layer of material only about one foot thick.

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LRO locates and photographs Odysseus on lunar surface

Overview map
Click for original LRO image of Odysseus

Scientists using Lunar Reconnaissance Orbiter (LRO) this weekend located and photographed Intuitive Machines’ Odysseus Nova-C lunar lander at a height of 56 miles during its first orbit over the site.

The inset in the map to the right shows the lander, with the white dot marking its landing site, several miles to the south of the planned landing site, as indicated by the yellow dot.

Odysseus came to rest at 80.13 degrees south latitude, 1.44 degrees east longitude, 8,461 feet (2,579 meters) elevation, within a degraded one-kilometer diameter crater where the local terrain is sloped at 12 degrees.

That slope could by itself explain why the lander tipped over and ended up on its side. First, it landed faster than planned. Second, Intuitive Machines designed this Nova-C lander with a relatively tall configuration, which gives it a high center of gravity. Hitting the ground fast and on such a slope could easily have been enough for momentum to tilt it over after touchdown.

Mars’ flaky rocks

Mars' flaky rocks
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on February 21, 2024 by the high resolution camera on the Mars rover Curiosity. It once again shows us a very typical many layered rock that the rover has seen routinely in Gale Crater and in the foothills of Mount Sharp.

The long flake tells us many things. First, Mars’ one-third Earth gravity, thin atmosphere, and lack of life allows such flakes to survive. On Earth not only would wind and rain break such delicate forms, plant life would eat away at it as well.

Second, the many thin layers tell us again that Mars’ geological history comprises many cycles and geological events, each of which placed another layer down. The many layers here could actually be evidence of year-by-year events, much like tree-rings detail the drought conditions yearly on Earth.

It will take study on Mars however to find out. These image only tantalize. They cannot give answers.

Frozen lava rapids on Mars

Frozen lava rapids on Mars
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on October 6, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows a spot on Mars where lava was squeezed between and around some small peaks as it flowed quickly south, flooding all the low areas in this landscape.

The science team describes the features in the full image as “streamlined”, a description that is literally accurate. As this “stream” of lava rushed past, it “lined” the higher terrain, carving it into tear-dropped shapes.

In the color strip, note the blueish spots at the northern base of the 400-foot-high hill. According to the science team’s explanation [pdf] of the colors in MRO images, “Frost and ice are also relatively blue, but bright, and often concentrated at the poles or on pole-facing slopes.” The picture was taken in summer, so if these bright spots are frost or ice, it suggests they are well shaded from sunlight in those north-facing alcoves. This location is only 9 degrees north of the equator, so finding any near surface ice here is highly unlikely. That frost might exist however is intriguing, to say the least.
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Curiosity’s view of Gale Crater from its new heights on Mount Sharp

Low resolution version of panorama
Click for full resolution version of panorama. For the original images, go here, here, and here.

Overview map

Cool image time! The panorama above was created from three pictures taken on Februay 13, 2024 by the left navigation camera on the Mars rover Curiosity (available here, here, and here). It looks to the north, across Gale Crater and its nearest rim, about twenty miles away. The red dotted line indicates the approximate route Curiosity took to get to this point. The yellow lines on the overview map to the right show the approximate area covered by the panorama.

The images were part of the routine mosaics created by both the left and right navigation cameras for helping engineers plot the rover’s future travels. The pictures that look back at the far rim however also provide important atmospheric data. In this case, the haze tells the scientists how much dust is in the atmosphere. It is presently winter in Gale Crater, which also corresponds to the dust storm season. Thus, the view is very hazy.

Curiosity will likely remain at this location for several more weeks, as the science team is about to begin another drilling campaign. Note the large dark area on the cliff face on the right that is also level with the terrace where Curiosity presently sits. The scientists want to get core data of this layer, and they think they are at a good spot to do so.

Martian gullies caused by glacial and water erosion

A gully on the north rim of Niquero Crater
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on December 23, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The image shows us the north interior rim of 7-mile-wide Niquero Crater on Mars. From the high to the low points the elevation difference is about 2,500 feet, with a steep downhill slope averaging about 18 degrees. The terrain appears to show several avalanche collapses that pushed lower material out of the way, though at the bottom where that material has been pushed aside there is no obvious large debris pile.

The science team labels this image simply “volatiles and gullies”, a label that carries a host of significant information. These gullies, which were among the earliest found by Mars Global Surveyor in the late 1990s, were the first evidence that the surface of Mars had a lot of near surface ice. It is for this reason that this relatively small crater on Mars has a name. Most craters this small remain unnamed, but the gullies on Niquero’s north slopes required more study, and thus the crater was given a name.

Subsequent orbital imagery has now shown that craters like Niquero, located in latitudes higher than 30 degrees, quite often are filled with glacial debris. In fact, the material that these avalanches pushed aside at the base of the slope is that glacial material, protected by a thin layer of dust and debris. The avalanche essentially disturbed that protected layer, and thus the debris pile (made up mostly of ice) sublimated away when warmed by sunlight. Thus. no big debris pile.

The gullies tend to be on the pole-facing slopes. Scientists believe they are the remnant evidence of ancient glaciers that grew on these slopes because they were protected from sunlight. In subsequent eons, when the climate on Mars changed, those glaciers collapsed, leaving behind the gullies we see now.
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Alternating dark and light terraces inside Valles Marineris

Overview map

Alternating dark and light layered terraces in Valles Marineris
Click for original image.

Cool image time! The picture to the right, cropped and enhanced to post here, was taken on October 9, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what appear to be the somewhat typical terrain at this location, in a part of the giant Martian canyon Valles Marineris dubbed West Candor Chasma. For example, I featured similar swirls in August 2022 at a place only about six miles to the east, that spot indicated by the green dot on the overview map above. The white dot marks the location of today’s image.

So, what are we looking at? The elevation drop from the high and low points is only about 180 feet, but in that short distance it appears there are more than two dozen visible layers, and those layers form terraces that alternate between bright and dark material.

The shape of the swirls also suggest that a flow of some kind, either water, ice, or wind, moved from the northwest to the southeast, carving these terraces as it descended the stair steps downward. It is also just as likely that we are seeing repeated lava flows going downhill to the southeast, each even laying another layer on top of the preceeding one. And it is also possible that we are looking at a combination of both.

The alternating dark and light layers suggest that each dark layer was an event that put down dark material, such as volcanic dust, that was subsequently covered with light material, with this process repeating itself many times over the eons.

That the floor of this part of Valles Marineris is uniquely covered in this manner is in itself intriguing. Why here, and not elsewhere within the canyon?

The alien surface of Mars

The alien surface of Gediz Vallis
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Overview map
Click for interactive map.

Cool image time! The picture above, brightened slightly to post here, was taken on February 15, 2024 by the right navigation camera on the Mars rover Curiosity. It looks east at the looming cliff face of the mountain Kukenan that the rover has been traveling beside for the last six months. On the overview map to the right the yellow lines indicate roughly the area covered by this picture. The blue dot marks Curiosity’s present position, while the green dot marks its position on February 5, 2024. As you can see, the rover is making slow but steady progress uphill into Gediz Vallis.

This image illustrates the alien landscape of Mars quite beautifully. First, there is absolutely no life in this picture. On Earth you would be hard pressed to find any spot on the surface that doesn’t have at least some plant life.

Second, there is the rocky layered nature of this mountain. When the Curiosity science team first announced its future route plans (the red dotted line) to drive into this canyon back in 2019, the orbital images of these layers from Mars Reconnaissance Orbiter (MRO) had suggested the terrain here would be reminiscent of The Wave in northern Arizona, a smooth series of curved layers smoothed nicely over time by the wind.

As you can see, there is no smoothness here. Instead, every single layer here is infused with broken rock, suggesting that each layer is structurally weak. As erosion exposes each, the layer breaks up, crumbling into the chaos in this picture. The curved nature of the terrain at the bottom of the picture however does suggest that some sort of flow once percolated down this canyon, either liquid water or glacial ice, carving the layers into this curved floor.

The shoreline of a Martian lava sea

The shoreline of a Martian lava sea
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken on October 2, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The science team labeled this a “lava margin.” The darker material on the right is apparently a newer deposit of lava, flowing on top of the lighter lava on the left. The newer deposit is only about three feet thick, so it had to have flowed fast almost like water to cover this large area with such a thin layer before freezing. Even so, this new lava layer has a roughness greater than the older layer below it. Either the older layer is smoother because of erosion from wind over eons, or the lava in these two layers was comprised of slightly different materials that froze with different textures.

The small ridges appear to be wrinkle ridges, created when material shrinks as it freezes.

This margin marks the edge of a very large flood lava event, as illustrated by the overview map below.
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