India’s Mars orbiter Mission (MOM) has confirmed that the periodic Martian global dust storms act to accelerate the loss of the red planet’s atmosphere.
The U.S. orbiter MAVEN found the same thing during the 2018 global dust storm. Moreover, the two orbiters focused on observing different hemispheres (MOM in the morning and MAVEN in the evening), and bot got comparable results.
In our on-going exploration of Mars using the amazing high resolutions being taken by Mars Reconnaissance Orbiter (MRO), we return today to Kasei Valles, the drainage valley coming down from Mars’ giant volcanoes that I featured only a few days ago. And like that post, we must begin from afar and zoom in to understand what we are seeing in the final cool image.
Kasei Valles is a canyon system is about 1,900 miles long, and would cover two-thirds of the continental United States if placed on Earth. Its north-trending upstream section to the west and south of the area shown on the overview map to the right is thought to have been formed by some combination of glacial and volcanic processes. The downstream west-east section shown in the map instead appears to have been formed by a sudden catastrophic flood, which some scientists have theorized [pdf] occurred when a three hundred long ice dam broke suddenly, releasing the flood quickly across this terrain to create its features. The second map to the right, from their paper, illustrates this hypothesized event.
The white box in 60-mile wide Sharonov Crater near the center of the first map above indicates the location of today’s cool image below. The 1976 landing site of VIking 1 about 420 miles to the east is also indicated.
If you look closely at the first overview map above you can see that the rim of Sharonov Crater appears breached in its southwest quadrant, just to the west of the white box. This breach is less a break and more an area of increased erosion. Regardless, it sure appears that a massive flow pushed through the rim here.
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For today’s cool image, we are going to start from afar and zoom in, because I think that might be the best way to gain at least a rudimentary understanding of the strange geology visible at this one particular Martian location.
The first image, to the right, is the overview map. The red cross indicates our target, a chaotic canyon that flows into the larger Kasai Valles, one of Mars’ largest and longest canyons and possibly only exceeded in size by Valles Marineris. This part of Kasai is near its end, where it drains out into the vast northern lowland plains of Mars.
The second image, below, comes from the wide angle camera on Mars Reconnaissance Orbiter (MRO).
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Click for full image.
An update today on the mole digging tool on the Mars lander InSight has revealed that the mole appears to finally be completely buried, though it remains unclear whether its most recent digging effort had succeeded in digging downward.
We found that during the first two rounds of hammering and during the first half of the third round of hammering, the scoop went further into the sand. Since the Mole was hidden under the scoop, the penetration of the probe itself could not be observed directly.
During the hammering, the flat tether running to the probe moved considerably, but these could only be clearly identified as forward movements during the hammering on 22 August. Overall, we could estimate from the movements of the scoop that the Mole moved at most one centimetre further into the ground. It was interesting to observe that during the second half of the round of 250 hammer blows on 19 September, the scoop did not go any further, probably because it encountered duricrust. This was certainly a desired outcome, as it allowed a second Free Mole Test to be conducted. In fact, the probe continued to move according to the movements of the tether, but it could not be clearly determined that these movements brought the Mole deeper into the ground.
The image shows InSight’s arm above the filled hole, with the mole’s flat tether coming out of the ground.
They are now going to fill the hole more, and then press down with the scoop during later drilling efforts to see if this allows the mole to proceed downward. If it fails I’m not sure if there is anything else they will be able to do to get the mole to work.
Click for full image.
No, today’s cool image is not a variation of the absurd “face on Mars” that our alien-obssessed fantasy culture focused on for more than twenty years that turned out to be nothing more than a mesa whose shadows in one image made it look very vaguely like a face.
Instead, today’s cool image is of a very weird Martian geological feature that strongly resembles the whorls and curls seen in all fingerprints, and is thus apply named “Fingerprint Terrain.”
The photo to the right, rotated, cropped, reduced, and annotated to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter on August 26, 2020. It shows part of the surface of Mars’ south pole residual icecap, about 130 miles from the south pole, at a place where the temporary thin dry ice mantle that arrives every winter with the bulk of it sublimating away with the coming of spring.
The fingerprint in this image shows that sublimation process, with the gaps in dry ice mantle getting wider and larger as you move north, until the ridges between disappear altogether.
But why does it look as it does, like a fingerprint? In other places this sublimation process does not look like this at all. Sometimes we get spiderlike formations. Sometimes we get splatters that suggest geysers. Sometimes the surface sublimates to produce swiss cheese shapes. But why a fingerprint here?
I asked this question of Shane Byrne of the Lunar and Planetary Lab University of Arizona, who had requested this particular image, hoping he and other planetary scientists had investigated this geology and come up with an explanation. His answer illustrates how little we yet know about Mars.
It’s almost definitely some sort of sublimation process, but it hasn’t been well investigated. There are some papers that talk about sublimation landforms on the cap in general and map out where different types are, but nothing that I know that’s specific to the fingerprint terrain.
In other words, why the dry ice cap sublimates away in this manner, at this and other locations, remains unexplained.
I’ll say it again: Mars is strange, Mars is alien, and Mars is therefore a place humans must go.
Click for full image.
Cool image time! The photo to the right, cropped and reduced to post here, was taken on June 29, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). In this one spot we see three obvious volcanic features, all however formed by different processes.
The location of this image is west of Olympus Mons. It sits on the vast lava plain that was laid down by that volcano, the largest in the solar system.
In order of likely occurrence, the cone probably came first. It likely indicates a past eruption coming up from below to create a small volcano.
The shallow meandering channel that sweeps around it to the north and east probably marks a later lava flow coming down from Olympus Mons.
The deeper straight fissure to the south probably came last. It is a graben, a crack caused by the uplift of the entire surface because of pressure from a magma chamber below, causing cracks to form as the surface is stretched.
Three different volcanic events, each probably taking thousands of years, with maybe thousands to millions of years between them. The context map below adds weight to the scale of time and size represented by this one Martian photo.
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Click for full image.
If you ever had any doubt about the existence of glaciers on Mars, today’s cool image should ease those doubts. The photo to the right, taken on August 27, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and rotated, cropped, and reduced to post here, shows many features that are appear identical to features found on typical massive glaciers on Earth.
Downhill is to the northwest. The many parallel grooves or fractures running along the length of the glacier resemble what are seen in many similar Earth glaciers. Some of these fractures are caused by the glaciers slow drift downward, with different sections moving at slightly different rates, thus causing a separation along the flow. Hence the parallel fractures.
These fractures also show evidence of some erosion. Because these Martian glaciers are no longer getting more snowfall, they are no longer growing. However, if the thin layer of dust and debris that protects the ice gets blown off or removed by motion, the ice is exposed and can then sublimate into gas so that the glacier erodes.
On the flow’s edges the darker parallel lines also resemble features seen on Earth, showing the exposed layers of the glacier’s past levels. The same thing can be seen on either side of the canyon’s walls.
The wide smooth section near the center of the parallel lines could very well be an impact crater that landed on this glacier sometime in the far past, and has since been distorted in shape as the glacier flowed downward.
If you still have doubts, the context image below, taken by MRO’s wide angle context camera, should help further allay those doubts.
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Click for full image.
Though the number of new pictures showing pits and possible caves from the high resolution camera on Mars Reconnaissance Orbiter (MRO) has significantly tailed off in the past year, as I noted in my previous post on Martian pits in September, the pictures are still rolling in. This post will highlight five new photos and the pits therein.
The first two, on the right, are both located on the southern flanks of the giant volcano Arsia Mons, where many such pits are found. They were taken respectively on August 16, 2020 and August 27, 2020. The first was a captioned image from MRO’s science team:
In this image, the ceiling of the lava tube collapsed in one spot and made this pit crater. The pit is about 50 meters (150 feet) across, so it’s likely that the underground tube is also at least this big (much bigger than similar caves on the Earth). HiRISE can’t see inside these steep pits because it’s always late afternoon when we pass overhead and the inside is shadowed at that time of day.
What I find most interesting about both images is that the skylights do not occur where you’d expect. In image #1, the meandering rill that suggests an underground lava tube is about 1,000 feet south of the pit. The pit itself seems unrelated to that rill. In image #2, the surface shows no obvious evidence of an underground tube matching the three aligned pits. There is the hint of a narrow depression along the alignment of the three pits, but this could just as easily be evidence of wind-blown dust along that alignment.
In the full image all three pits appear to sit inside a very wide and very shallow northwest-to-southwest depression, but this is hardly certain, and regardless the three pits align in a different direction.
The overview map below provides some context.
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Capitalism in space: SpaceX’s eighth Starship prototype has passed its tank, thruster, and even fin tests, setting it up for the installation of its three Raptor engines.
Once installed, they will perform several static fire tests, on the launchpad. If those tests are successful, the company will then proceed with a full 50,000 foot test flight. Based on the pace of operations, my guess is that this hop will occur in about two to four weeks.
I’ve embedded one of the videos at the link below the fold, showing a variety of activity at the site.
In other SpaceX news, the Tesla that was put in solar orbit on the first Falcon Heavy test launch has just made its first “fly-by” of Mars, getting to within 5 million miles of the red planet. At that distance the planet really isn’t very close, which is why I put the word fly-by in quotes. That Tesla’s future:
The Roadster will eventually barrel into either Venus or Earth, likely within the next few tens of millions of years, a 2018 orbit-modeling study determined . But the chances of an Earth or Venus impact in the next million years are just 6% and 2.5%, respectively.
Click for full image.
Cool image time! The crater on the right, the image cropped and reduced to post here, is a great example of many craters scientists have found in the mid-latitudes on Mars containing a variety of features that suggest buried glaciers. In this case we are looking at what they have dubbed a concentric crater fill, material that resembles glacial material that fills the crater’s interior and floor, and appears often to erode in a series of rings. You can see another example here.
The photo was taken on June 29, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The crater itself is located in a region of chaos terrain dubbed Nilosyrtis Mensae, located in the transition zone between the cratered southern highlands and the lowland northern plains.
Nilosyrtis Mensae is part of a region of Mars I call glacier country. When you include the mensae regions Protonilus and Deuteronilus to the west, this transition zone of random mesas, knobs, and criss-crossing canyons stretches about 2,000 miles. The context map below focuses in on Nilosyrtis Mensae, where this crater is located.
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China has released several images taken of its Tianwen-1 orbiter/lander/rover by a camera ejected by the spacecraft on its way to Mars.
The images released by the China National Space Administration on Oct. 1 show the Tianwen 1 spacecraft traveling through the blackness of space. Tianwen deployed a small camera to take the self-portrait as it tumbled away from the mothership.
Two wide-angle lenses on the deployable camera were programmed to one image every second. The images were transmitted back to Tianwen via a wireless radio link, then downlinked back to ground teams in China.
In the images, Tianwen 1’s solar array wings and dish-shaped high-gain communications antenna are prominently visible. The white section of the spacecraft is the mission’s entry module and heat shield, which contains a Chinese rover designed to land on Mars and explore the surface.
The spacecraft is about halfway to Mars, and will arrive in Mars orbit in February. It will then spend several months surveying its candidate landing sites, of which there appear to be two, before releasing the lander/rover to the surface.
Click for full image.
Today’s cool image to the right, cropped to post here, shows an ice scarp located in the high southern latitudes south of Hellas Basin. It was taken on August 15, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and was released today as a captioned image. From the caption:
Scientists have come to realize that, just below the surface, about one third of Mars is covered in ice. We study this ice to learn about Mars’ ancient climate and astronauts’ future water supplies.
Sometimes we see the buried ice because cliffs form like the one in this image. On the brownish, dusty cliff wall, the faint light-blue-colored ice shows through. [emphasis mine]
This ice scarp is one of about two dozen [pdf] that have so far been found within the latitude bands of approximately 45 to 65 degrees latitude in both the north and south hemispheres. The data so far obtained suggests that the scarp exists because of a pure water ice layer just below the surface. Over time this pole-facing cliff retreats away from the pole towards the equator, leaving behind it an extended pit. In the cliff wall scientists think they have detected evidence of that water ice layer.
Blue in MRO hi-res images can indicate both water as well as very rough surfaces. While much of the blue here could be ether, the blocky cracks suggest it is ice. As explained by Colin Dundas of the U.S. Geological Survey’s Astrogeology Science Center in Arizona and lead author of the pdf above,
The crack patterns are likely thermal contraction cracks, which form in shallowly buried ice due to seasonal temperature changes causing it to expand and contract. When that repeats over many years it creates regular patterns of cracks that organize themselves into polygons.
The overview image below gives the location of all known such scarps, as of March of 2020, taken from the pdf paper that I linked to above.
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