Frozen waves of Martian lava?

Frozen waves of Martian lava?
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on March 17, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team labeled this a terrain sample image, which implies it was taken not as part of any specific request, but to fill a gap in the camera’s schedule in order to maintain its proper temperature.

What are we looking at? This stippled terrain with curved ridges actually extends quite a distance beyond this image. A MRO context camera picture taken on July 22, 2020 shows its full extent, about 10 miles wide but extending to the north and south about 30 miles total, butting up against a north-south mountain chain to its east that is about seventy miles long with its highest peak about 8,000 feet above this plain.
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Lunar Reconnaissance Orbiter spots Hakuto-R1 impact debris on Moon

Hakuto-R1 impact site, before and after
Click for original blink image.

NASA’s Lunar Reconnaissance Orbiter (LRO), scientists have spotted what they think is the impact debris produced when Ispace’s private lunar lander Hakuto-R1 crashed on the Moon on April 25, 2023.

To the right are two LRO images, the first at the top taken prior to Hakuto-R1’s landing attempt. The second at the bottom was acquired by LRO on April 26, 2023, the day after that attempt. The lettered arrows indicate four spots where the scientists identified changes between the two pictures. From the caption:

Arrow A points to a prominent surface change with higher reflectance in the upper left and lower reflectance in the lower right (opposite of nearby surface rocks along the right side of the frame). Arrows B-D point to other changes around the impact site.

According to the LRO science team, these changes suggest different pieces of debris, though it will take more analysis and more images under different lighting conditions to determine more precisely what they have found.

The presence however of four pieces strongly suggests that Hakuto-R1 hit the ground hard enough to break apart. Based on the initial data received during landing, it was thought the spacecraft had touched down softly but then was damaged by some unforeseen obstacle on the ground, such as a large boulder. The LRO image suggests instead that it did not touch down softly at all.

Ancient volcano vent in the Martian southern cratered highlands?

Ancient volcano vent on Mars?
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The nature of today’s cool image suggests both ancient and more recent geological activity, each coming from entirely different sources but both helping to shape the alien Martian surface.

The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on March 13, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team has labeled an “elongated depression,” sitting in the middle of a relatively flat but very rough stippled circular plain about 60 miles in diameter. An MRO context camera picture, taken on February 19, 2012, covered the central strip of this plain, and shows that its surface is equally rough and stippled everywhere, with only a few craters and one or two slight changes in elevation.

So, how does this feature tell us both about the ancient and recent geological history of this spot on Mars?
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Buried dying glacier in the Martian dry equatorial regions?

Buried glacial ice in dry equatorial regions?
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Today’s cool image from Mars is not so much unique visually as it is unique in terms of its location. The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on January 31, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the northern rim of a small crater, with its floor filled with an intriguing mound of material.

The picture was labeled a “terrain sample”, which suggests it wasn’t taken as part of any specific research project by instead to fill a gap in the camera’s schedule. To maintain the camera’s proper temperature, it is necessary to take pictures regularly, and when the camera team finds a gap that is too long, they fill it by choosing some almost random target in that gap that might be interesting. Sometimes it is, sometimes not.

In this case I strongly suspect this target was hardly random. The picture title also mentions MRO’s now retired radar CRISM instrument, which was used to detect evidence of underground ice. My guess is that the camera team thus likely decided to image this crater in high resolution because that radar data suggested the presence of underground ice.

This guess is strongly confirmed by a context camera picture taken of this crater on September 1, 2008. The crater appears surrounded by the typical splash apron one routinely sees around impact craters in the mid- and high-latitude northern lowland plains, where there is a lot of near surface ice.

The bumpy mound seen in high resolution on the floor of this crater could very well be buried glacial ice, as it mimics similar features in the many craters in the mid-latitudes of Mars. But is it buried ice? The location says otherwise.
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Lucy makes course correction in preparation for 1st asteroid fly-by

Lucy's route through the solar system
Lucy’s route through the solar system

The asteroid probe Lucy on May 9, 2023 fired its engines to successfully make a minor course correction in preparation for a fly by of the asteroid Dinkinesh, located in the main asteroid belt between Mars and Jupiter.

Even though the spacecraft is currently travelling at approximately 43,000 mph (19.4 km/s), this small nudge is enough to move the spacecraft nearly 40,000 miles (65,000 km) closer to the asteroid during the planned encounter on Nov. 1, 2023. The spacecraft will fly a mere 265 miles (425 km) from the small, half-mile- (sub-km)-sized asteroid, while travelling at a relative speed of 10,000 mph (4.5 km/s).

Dinkinesh, the white dot inside the main asteroid belt in the lower left of the map to the right, is the first of eight asteroids Lucy will fly past.

Chaos in the southern cratered highlands of Mars

Chaos in the southern cratered highlands of Mars
Click for full image.vi

Today’s cool image takes us to a part of the cratered southern highlands of Mars that I have not featured much previously. The picture to the right, rotated, cropped, and reduced to post here, was taken on March 7, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what appears to be a collection of rough hills and mesas surrounded by a sea of smooth ground that at the base of the cliffs seems to end abruptly.

The smooth ground is probably mantled by a layer of dust and debris. Since this location is at 36 degrees south latitude, there is also probably near surface ice under that layer. The abrupt edges likely indicate where the increasing slope next to the mesas and mounds caused that ice to be exposed and thus sublimate away.

As for the location, we must go to the overview map.
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Astronomers discover Earth-sized planet 90 light years away

Using data from a variety of space- and ground-based telescopes astronomers have discovered Earth-sized exoplanet orbiting a red dwarf star 90 light years away.

The exoplanet is dubbed LP 791-18 d, and is thought to be slightly bigger than the Earth. Its orbit, close to the star, causes it to be tidally-locked, with one hemisphere always facing the star. In addition, the presence of another much larger exoplanet in the system causes other tidal effects.

Astronomers already knew about two other worlds in the system before this discovery, called LP 791-18 b and c. The inner planet b is about 20% bigger than Earth. The outer planet c is about 2.5 times Earth’s size and more than seven times its mass.

During each orbit, planets d and c pass very close to each other. Each close pass by the more massive planet c produces a gravitational tug on planet d, making its orbit somewhat elliptical. On this elliptical path, planet d is slightly deformed every time it goes around the star. These deformations can create enough internal friction to substantially heat the planet’s interior and produce volcanic activity at its surface. Jupiter and some of its moons affect Io in a similar way.

The press release makes a big deal about the volcanism, even suggesting it could produce an atmosphere that, because the exoplanet sits on the inner edge of the habitable zone, could make the exoplanet habitable. These speculations are silly, considering the uncertainties, the exoplanet’s evolving orbit, and the star it orbits, and are being pushed mostly because the press office thinks this will be the only way the public will have any interest in the discovery.

While there is an infinitesimal chance there could be life here, a more likely scenario is that it is a lifeless volcano world like Jupiter’s moon Io. Even more probably however is that it is completely different than anything we have yet observed, in ways we can’t yet predict. To find out however we would need close-up observations that will likely not be possible without an interstellar mission.

Final assembly of Chandrayaan-3 begins for launch still targeting mid-July


Click for interactive map.

Engineers at India’s space agency ISRO have begun the installation of the payloads onto its lunar lander/rover, Chandrayaan-3, which is still targeting a mid-July launch.

The map shows the landing location (red dot) near the Moon’s south pole (indicated by the cross). Nova-C is Intuitive Machines private lander, now aiming for a late summer launch at the earliest. Luna-25 is Russia’s first lunar lander since the 1970s, and is also targeting a launch in July.

India’s first attempt, Chandryaan-2, to land a rover at this spot on the Moon failed in 2019. This new mission is essentially a re-do, except that it does not include an orbiter, since the orbiter from Chandrayaan-2 is still operational and can do the job.

All in all, it increasingly looks like the next six months will see a lot of new landing attempts on the Moon.

Alien textured Martian lava

Alien textured Martian lava
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken on February 17, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what the science team labels “regularly textured ground on Pavonis Mons.”

The arrow in the picture indicates the downhill trend. If you look at the full image, you will see that this texture pattern extends in all directions for a considerable distance, both uphill and down, and even covers the entire floor of a depression that appears to contour along the grade instead of going downhill.

The latitude here is very close to the equator. So, even though the elevation is high, being on the slopes of a giant volcano, there is probably no near surface ice here.
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What kind of barred spiral galaxy is the Milky Way?

Three types of barred spiral galaxies
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The uncertainty of science: Though astronomers have long believed that the Milky Way galaxy is a barred spiral galaxy, defined as having a major straight arm coming out in two directions from its nucleus with other spiral arms surrounding it, determining the exact structure has been difficult because of our presence within the galaxy.

The image to the right, taken from a paper just published, shows three different types of barred spirals. On the left is one where the surrounding spiral arms hardly exist. In the center the central bar is surrounded by multiple arms. On the right is a barred spiral with just one major spiral arm.

Though it has been generally accepted that the Milky Way belongs in the center category, astronomers remain unsure about the actual spiral structure. Previous work had suggested the galaxy actually had four major arms, not two as seen by most barred spirals. As noted in the paper, “If that is the case, the [Milky Way] may be an atypical galaxy in the universe.”

The research from the new paper however now proposes that the Milky Way is actually not atypical, but instead more resembles the center image, with two main arms and multiple segmented arms beyond. From the abstract:

Using the precise locations of very young objects, for the first time, we propose that our galaxy has a multiple-arm morphology that consists of two-arm symmetry (the Perseus and Norma Arms) in the inner parts and that extends to the outer parts, where there are several long, irregular arms (the Centaurus, Sagittarius, Carina, Outer, and Local Arms).

The astronomers cheerfully admit that this conclusion is uncertain, and will need many further observations for confirmation.

Brain terrain in and around pedestal crater on Mars

Brain terrain in and around a pedestal crater on Mars
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on March 10, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

As I noted in a cool image only two weeks ago, brain terrain is a geological feature wholly unique to Mars that planetary geologists still do not understand or can explain. They know its knobby interweaving nodules (resembling the convolutions of the human brain) are related to near surface ice and its sublimation into gas, but no one has much confidence in any of the theories that posit the process that forms it.

In this case the brain terrain not only fills the crater, it appears to surround it as well, but only appearing at spots where a smooth top layer has begun to break apart. Moreover, the crater appears to be a pedestal crater, whereby much of the less dense surrounding terrain has vanished, leaving the compacted crater sitting higher.
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Glacial sinkhole in the Martian southern cratered highlands?

Overview map

Glacial sinkhole in the Martian southern cratered highlands?
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken on February 21, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). This is a terrain sample image, which means it was snapped not as part of any specific research project but to fill a gap in the schedule in order to maintain the camera’s proper temperature. As usual, the camera team tried to pick something of interest, and I think they succeeded.

The two large depressions in the center of the picture do not resemble impact craters. They have no rim of ejected material and their shape is very distorted. Instead, both appear to be places where a top layer of ice/debris has sublimated away into gas, exposing a lower layer of glacial material that itself is sublimating away to form the bumpy mounds that fill the floor of the depressions.

The white dot inside the inset box on the overview map above marks this location, just south of the northern wall of a large 30-mile-wide canyon, with its northern floor even more depressed, as if the material in that raised middle a flat pile of glacial debris flowing to the southwest after leaving the gap in the crater to the northeast. An MRO context camera picture taken on January 6, 2016 gives a wider view, showing that there are a lot of these type depressions on the surface of this wide middle upraised floor, as well as some obvious impact craters.

This location is in the mid-latitude band where many glacial features are found. In this part of the southern cratered highlands there is also a lot of evidence of top layers sublimating away, as if the glacial material is a large buried ice sheet that is beginning to disappear at places where it has been exposed by impacts or shifting motion. The depression in the picture above appears to be an example.

Engineers free stuck radar antenna on Juice probe to Jupiter’s big moons

Engineers have successfully freed the 52-foot wide radar antenna on the Juice probe to Jupiter, shaking it enough to release a pin that was blocking deployment.

The pin was freed by employing “back-to-back jolts”. Imagine when you roll your car back and forth to get it freed from mud or snow. It appears this is what they did with the pin.

Juice will arrive in Jupiter orbit in 2031, where it will make numerous fly-bys of Europa, Calisto, and Ganymede, and then settle into an orbit around Ganymede alone. The radar antenna was essential for probing the ice content of these worlds, below the surface.

Hat tip to reader Mike Nelson.

Endless dunes amidst Mars’ giant volcanoes

Endless dunes amidst Mars' giant volcanoes
Click for originial image.

Past cool images on Behind the Black showing endless dune fields on Mars have generally focused on two places, the giant Medusae Fossae Formation volcanic ash deposits in the dry equatorial regions of Mars and the Olympia Undae dune sea that surrounds the Martian north pole.

Today’s image to the right, rotated, cropped, reduced, and sharpened to post here, takes us to a completely different dune sea. Taken on February 14, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), the picture also shows an endless dune sea, though there is faint evidence on those dune fields of buried features, such as the meandering east-west feature in the picture’s center.

This dune sea is also in the dry equatorial regions, like Medusae, but it is much farther east, and sits surrounded by Mars’ biggest volcanoes.
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Perseverance data suggests a strong river rushed down the delta in Jezero Crater

Skrinkle Haven on Mars
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Based on the images and geology so far gathered by the Mars rover Perseverance as it has climbed up onto the delta that flowed into Jezero Crater sometime in the far past, scientists now think a roaring river once flowed down that delta.

Years ago, scientists noticed a series of curving bands of layered rock within Jezero Crater that they dubbed “the curvilinear unit.” They could see these layers from space but are finally able to see them up close, thanks to Perseverance.

One location within the curvilinear unit, nicknamed “Skrinkle Haven,” is captured in one of the new Mastcam-Z mosaics [a section of which is posted to the right]. Scientists are sure the curved layers here were formed by powerfully flowing water, but Mastcam-Z’s detailed shots have left them debating what kind: a river such as the Mississippi, which winds snakelike across the landscape, or a braided river like Nebraska’s Platte, which forms small islands of sediment called sandbars.

When viewed from the ground, the curved layers appear arranged in rows that ripple out across the landscape. They could be the remnants of a river’s banks that shifted over time – or the remnants of sandbars that formed in the river. The layers were likely much taller in the past. Scientists suspect that after these piles of sediment turned to rock, they were sandblasted by wind over the eons and carved down to their present size.

The press release say nothing about glacial activity here, but I am willing to bet the scientists have considered this. As it requires a greater leap into the unknown, involving geological processes not yet understood on an alien planet, it is makes sense that they have put it aside at this point. I also am willing to bet that it will pop up again, with time and additional data.

Is this ice or lava in the death valley of Mars?

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

To put it mildly this is strange terrain. The curving east-west feature resembles a glacial flow, but it also has features that say otherwise. For example, what could cause that gap in the middle of the picture? Such things are not usually seen in an ice flow. Then there is that filled crater on the center left edge of the picture, inside the flow. Though filled with material, the flow itself does not flow around the crater, suggesting the impact occurred after the flow. Moreover the crater is a pedestal crater, whereby the surrounding terrain has eroded away so that the crater ends up standing above it.

These facts suggest that this flow is very old, and has not flowed for a very very very long time. This in turn suggests it isn’t ice but solidified lava, though for a lava flow it also has features that are anomalous when compared to typical flood lava on Mars.
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A rash on Mars

A Martian rash
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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on January 30, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team labeled this a “Circular Outcrop of Bright Rock.

What I see is a Martian skin rash. Based on the ripple pattern below the ridge one might think we are looking at sand dunes, except that the rash above the cliff has no such pattern. Instead, the ground in this one particular area looks very roughened in a random sort of way.

The location at 27 degrees south latitude suggests there is little near surface ice at this location to cause this feature. The overview map below provides another but not very helpful possibility.
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Paperwork on Mars

Paperwork on Mars
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Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on April 15, 2023 by the close-up camera on the Mars rover Curiosity. From the caption:

NASA’s Curiosity Mars rover took this close-up view of a rock nicknamed “Terra Firme” that looks like the open pages of a book, on April 15, 2023, the 3,800th Martian day, or sol, of the mission, using the Mars Hand Lens Imager (MAHLI) on the end of its robotic arm. The rock is about an inch across (2.5 centimeters).

Strange looking rocks like this have not been rare during Curiosity’s travels in Gale Crater, though it seems to me that the variety and strangeness has increased as the rover has climbed higher on Mount Sharp. In this case, the tall flake in the center — as well as the shorter flakes to the left — were among the many thin layers seen in this area. These layers however were clearly made of much harder material than the layers above and below. Those weaker layers eroded away over the eons, leaving behind these thin sheets.

Also, if you own red-blue 3D glasses, take a look at the anaglyph here.

Sinuous ridge inside Martian canyon

Sinuous ridge inside a Martian canyon
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Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on February 7, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the camera team labels a “sinuous ridge within valley.”

The location is at 30 degrees south latitude, right on the edge of the southern of the two 30-60 degree mid-latitude bands where orbital images show many glacial features. Closer to the equator and there is little or no evidence of near surface ice on Mars. Farther from the equator from this latitude and the evidence of near surface ice increases, becoming very dominant the closer to the poles you get.

At this spot, it appears there is little near surface ice. The channel has ripple sand dunes inside it, and the sinuous ridge appears to be bedrock. Similarly, the plateau above the channel also appears like bedrock, the craters showing no evidence of splatter that is common where there is near surface ice.

What made the channel? And what made that a sinuous ridge inside it?
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Brain terrain on top of Martian mountains

Brain terrain at high elevation on Mars
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Cool image time! The picture to the right, cropped and reduced to post here, was taken on March 26, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It is labeled by the scientists “Brain Terrain on Floor of Crater in Warrego Valles.”

Brain terrain is a geological feature entirely unique to Mars that remains unexplained in any way by geologists. The scientists know it is almost certainly related to near-surface ice and its sublimation into gas, but their theories as to its precise formation process remain incomplete and unconvincing, even to them.

In this case the brain terrain’s interweaving nodules seem to show flow patterns, but strangely those patterns go around depressions and hollows. Yet, the overall flow direction also seems to point downhill towards the slope on the image’s right edge.
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Weird dome near Starship candidate landing zone on Mars

Weird dome near Starship candidate landing zone on Mars
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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on February 27, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as domes in Arcadia Planitia, one of the many large northern lowland plains of Mars.

This to me is a “What the heck?” image. I won’t dare try to explain the warped concentric ringed pattern at the top of the mesa, nor the bright and dark splotch that surrounds it. The small craters around it appear to have glacier material within them, and the terrain here likely has a lot of near surface ice, being at 37 degrees north latitude in a region where the data suggests such ice exists. The different colors here likely indicate the difference between dust (orange) and coarser material (aqua).

The location, as shown in the overview map below, makes this mesa more tantalizing.
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In a Martian cold cauldron, boil and bake

bubbles and boiling ground
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Cool image time! My headline paraphrases slightly the witches’ chant from Shakespeare’s MacBeth, if only to make it more accurately describe the picture to the right, cropped and reduced to post here. Taken on January 5, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), it shows a patch of mid-latitude terrain in the icy northern lowland plains of Mars.

While some of the craters here were certainly caused by impact, it is also likely that most were instead cryo-volcanic in nature, whereby ice bubbles up from below as changing temperature conditions — none of which need to be very warm — cause it to either melt temporarily into liquid or sublimate directly into a gas. The dark pimplelike hole on the picture’s right edge is a perfect example, with the hole sitting at the top of a cone.
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SuperBIT balloon circling Antarctica snaps more high resolution astronomical pictures

Sombrero Galaxy
Click for full image.

The Super-Pressure Balloon Imaging Telescope (Super-BIT) that has been circling Antarctica for the last two weeks has now obtained two more more high resolution wide-field astronomical pictures.

The picture to the right, cropped to post here, is of Messier 104 (the Sombrero Galaxy). While the telescope cannot zoom in closer than this to such objects, it is able to get much wider and sharp pictures, covering an entire galaxy or nebula that ground-based telescope using adaptive optics (designed to counter the fuzziness caused by the atmosphere) cannot. Adaptive optics only work on very small fields of view, thus making it unable to observe some of the larger nearby astronomical objects like galaxies and nebulae.

If you look at the live stream of the balloon’s track, it has now almost completed its second circuit of Antarctica.

Astronomers record moment star eats planet

Animation of a star eating a planet
Click to watch full animation.

Using data from a variety of space- and ground-based telescopes, astronomers now think they have recorded the moment a star similar to our Sun actually swallowed a planet thought to be comparable to Jupiter or smaller.

Once the science team put all the evidence together, they realized the dust they were seeing with NEOWISE [in orbit] was being generated as the planet spiraled into the star’s puffy atmosphere. Like other older stars, the star had begun to expand in size as it aged, bringing it closer to the orbiting planet. As the planet skimmed the surface of the star, it pulled hot gas off the star that then drifted outward and cooled, forming dust. In addition, material from the disintegrating planet blew outward, also forming dust.

What happened next, according to the astronomers, triggered the flare of optical light seen by ZTF [survey telescope in California]. “The planet plunged into the core of the star and got swallowed whole. As it was doing this, energy was transferred to the star,” De explains. “The star blew off its outer layers to get rid of the energy. It expanded and brightened, and the brightening is what ZTF registered.”

Some of this expanding stellar material then escaped from the star and traveled outward. Like the boiled-off layers of the star and planet that previously drifted outward, this material also cooled to form dust. NEOWISE is detecting the infrared glow of all the newly minted dust.

The picture above is a screen capture from a short artist’s animation created to illustrate what happened. The most amazing aspect of this event is how long the planet skimmed the surface of that star. It appears it did so for several orbits at least.

The cliff wall of ancient Martian lava channel

The cliff wall of an ancient Martian lava channel
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Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on January 17, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) by the camera team not as part of any particular research project but in order to fill a gap in the camera’s schedule so as to maintain its proper temperature. In such cases the camera team tries to pick potentially interesting spots.

This cliff, about 1,100 feet high, is the north wall of a major volcano channel flowing across the Tharsis Bulge, the lava plains that surround Mars’ giant volcanoes. Located in the dry equatorial regions, there is no near surface ice here, but a lot of dust, much of it likely volcanic ash. In the full picture are several ancient craters, all of which are almost entirely buried by this dust and ash.

The cliff wall itself is made up of numerous layers, each representing a past volcanic flood lava event that covered this region with a new flow of material. These events occurred over more than a billion years.
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Exploring just one small corner of Valles Marineris, Mars’ Grand Canyon

One corner of Valles Marineris
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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on February 19, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the many many many layers that are found in the cliffs of Valles Marineris, the largest known canyon in the solar system and far far larger that Earth’s Grand Canyon.

The elevation difference between the red dots is just under 4,000 feet. Yet that high point is still more than 7,000 feet below the rim of the canyon, more than thirty miles to the south. And the lower dot is still about 18,000 feet above the low point in this side canyon of Valles Marineris, about thirty miles away to the northeast.

In other words, in sixty miles from rim to floor the canyon at this location drops about 25,000 feet, only 4,000 feet less than the height of Mount Everest. Compare that with the Grand Canyon’s slopes, which drops in eleven miles about 5,000 feet, beginning at the main south rim lookout at the start of Bright Angel trail.
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Galaxies without end

Galaxies without end
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Cool image time! The picture to the right has been significantly reduced but also significantly sharpened to post here. It was taken by the Hubble Space Telescope as part of a recent survey of “jellyfish” galaxies, galaxies located in galaxy clusters where there is a large concentration of galaxies whose combined gravity and intergalactic environment acts to pull material or “tendrils” out from the galaxy.

Rather than crop the image to focus on that single large central jellyfish galaxy, I have instead sharpened the much-reduced full photo to bring out clearly the number of surrounding galaxies. There is only one Milky Way star in this picture, the object with the four diffraction spikes in the lower-right. Every other dot is a galaxy, many of which can be seen to be very strangely shaped in the original full resolution image. In fact, I strongly recommend you click on the picture to explore that original image, just to see the variety of galaxy shapes.

The point of this picture today however is not to illustrate the wide variety of galaxies that can exist, but to underline the vast and largely incomprehensible scale of the universe. The large galaxy is thought to be 650 million light years away, which means it took light traveling at 186,000 miles per second that many years to get here. The surrounding galaxies are also all tens to hundreds of millions of light years from each other. Yet, their combined gravity, almost infinitesimal in strength, is enough to warp the shape of each.

We understand these numbers and facts intellectually, but do we understand them in reality? I think it is difficult, even if you work hard to come up with a scaled comparison. For example, it took nine years for the New Horizons spacecraft to get from Earth to Pluto, a distance of about 4.5 light hours. And New Horizons was the fastest traveling probe ever launched, moving at 36,400 miles per hour when it left Earth. Yet, this distance is nothing compared to the distance between these galaxies.

The vastness of existence really is beyond our comprehension. That we try to comprehend it speaks well of the human desire to achieve the impossible.

Glacier layers on the border of Hellas Basin

Dipping glacial layers
Click for original image.

Cool image time! The picture to the right, cropped and reduced to post here, was taken on February 21, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as “dipping layers”, referring specifically to the mesas with the terraces on their western flanks.

The layers obviously signify past cycles of geological events on Mars. That the terraces are only on one side of the mesas suggests that they are tilted, with the downhill grade to the east.

These layers however pose several mysteries. First, why are they located so specifically in only certain places of this region? It appears that the layered terrain is only found in the lower hollows and valleys. Why?

Second, why are they tilted at all?
» Read more

Frozen waves of lava on Mars

Frozen waves of lava on Mars

Cool image time! The picture to the right, cropped and reduced to post here, was taken on January 15, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows an area where the ground suddenly transitions from a crazy quilt of criss-crossing hollows and ridgelines to a very flat and smooth plain.

The location is at 21 degrees south latitude, so this is in the dry equatorial regions. Though it has a small resemblance to the chaos terrain that is found in many places on Mars, mostly in the mid-latitudes where glaciers are found, the scale here is too small and the ridges and canyons are not as sharply drawn. While chaos terrain usually forms sharply defined large flat-topped mesas with steep cliffs, here the ridges are small and the slopes to the peaked tops are somewhat gentle.
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One instrument on Mars Reconnaissance Orbiter ends its mission

Because Mars Reconnaissance Orbiter’s (MRO) CRISM instrument needed to be cooled to low temperatures to use infrared wavelengths for detecting underground minerals and ice on Mars, and the cryocoolers have run out of coolant, the science team has shut the instrument down.

In order to study infrared light, which is radiated by warm objects and is invisible to the human eye, CRISM relied on cryocoolers to isolate one of its spectrometers from the warmth of the spacecraft. Three cryocoolers were used in succession, and the last completed its lifecycle in 2017.

All the remaining instruments on MRO, including its two cameras, continue to operate nominally.

In its final task, CRISM produced a global map showing water related minerals on Mars, released last year, and a global map showing iron deposits, to be released later this year.

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