The new colonial movement: Japan revealed yesterday that it plans to send unmanned probe to Mars’ moon Phobos, using the basic designs developed for the asteroid mission Hayabusa-2.
Like Hayabusa-2, they will attempt to grab a sample from Phobos, and will launch in September 2024, returning its sample in 2029.
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Cool image time! The photo to the right, rotated, cropped and reduced to post here, was taken on January 3, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows three strange teardrop-shaped depressions, clearly wind-swept and partly buried by dust and sand.
The location on Mars of these depressions is in the transition zone between the southern cratered highlands and the northern lowlands. This is also a region dubbed the Medusae Fossae Formation, a region where it appears a great deal of volcanic material was laid down during one or more eruptive events 3 to 3.8 billion years ago.
Whether these depressions were formed during those events is impossible to tell from the available data, especially because the underlying bedrock is buried in dust.
Their shape appears to have been caused as the wind slowly exposed three buried peaks of hard rock. The wind, blowing from the southwest to the northeast, would hit the peaks, producing an downward eddy that would churn out dust from the windward side. The wind and dust would then blow around the peaks, creating the teardrop tail on the leeward side to the northeast.
NASA’s Mars Reconnaissance Orbiter, in space now for fifteen years, will undergo a two week computer software upgrade.
The maintenance work involves updating battery parameters in the spacecraft’s flash memory – a rare step that’s been done only twice before in the orbiter’s 15 years of flight. This special update is necessary because it was recently determined that the battery parameters in flash were out of date and if used, would not charge MRO’s batteries to the desired levels.
In addition to the battery parameters, engineers will use this opportunity to update planetary position tables that also reside in flash. The spacecraft will go into a precautionary standby mode, called safe mode, three times over the course of the update. It will also swap from its primary computer, called its Side-A computer, to its redundant one, called Side-B.
During these two weeks the spacecraft will suspend its science and communications operations.
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The image to the right, reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and provides a close-up of the relative smooth terrain found in the region on Mars that the Chinese have said is one of their prime landing sites for their 2020 Mars rover and lander. According to planetary scientist Alfred McEwen of the Lunar & Planetary Laboratory in Arizona,
There was a presentation at the European planetary & science conference in Geneva last fall, and a Chinese scientist gave an update on their plans and showed this area with the lat-long coordinates. That’s what I’m going on.
McEwen also admits that “there might have been a change since then. I’m not in the loop.” No one outside China really is, as that government remains quite opaque on these matters. They will likely only reveal their final landing site choice as we get closer to launch.
This location, on the northern lowlands plains of Utopia Planitia, makes great sense however for a first attempt by anyone to soft land on Mars. In fact, in 1976 these plains were the same location that NASA chose for Viking 2, for the same reasons. (The Viking 2 landing site was to the northeast of the Chinese site, just beyond the right edge of the overview map) While there are plenty of craters and rough features, compared to most of Mars’s surface, Utopia could be considered as smooth as a bowling ball.
Even so, a look at the full image shows that there are numerous features nearby that would be a threat for any robotic lander. McEwen notes,
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Cool image time! The photograph on the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on December 21, 2019. It shows the eastern half of the floor and interior rim of a large squarish-shaped crater or depression in what seems to be an unnamed region of chaos terrain located in the transition zone between the Martian southern highlands and the northern lowland plains.
The floor of this depression has many of the features that indicate the presence of a buried ice glacier, including flow features on the depression floor, linear parallel grooves, and repeating moraine features at the slope base. In fact, all these features give the strong impression that this crater is ice-filled, to an unknown depth.
Chaos terrain, a jumble of mesas cut by straight canyons, are generally found in this transition zone, and could be an erosion feature produced by the intermittent ocean that some believe once existed in the northern lowlands. Whether or not an ocean lapped against these mesas and created them, this chaos terrain is believed to have been caused by some form of erosion, either wind, water, or ice.
The location is of this chaos terrain in that transition zone is illustrated by the context map to the right. It sits on the edge of the vast Utopia Basin, one of the largest and deepest northern lowland plains. It also sits several hundred miles due north of the planned landing site of the Mars2020 rover in Jezero Crater. There is a lot of chaos terrain in this region, with lots of evidence of buried glaciers flowing off the sides of mesas.
Today’s image, with its numerous features suggesting the presence of a buried glacier filling the depression, reinforces this evidence.
What impresses me most about this particular depression — should it be ice-filled — is its size. I estimate from the scale of the image that the depression is about six miles across, somewhat comparable though slightly smaller than the width of the Grand Canyon. And yet, unlike the Canyon it appears to have a wide flat floor across its entire width. The second context map to the right zooms in on this chaos region to show how relatively large the depression is. It would not be hard to spot it from orbit. We don’t know the depth, but even if relatively shallow this depression still holds a heck of a lot of water ice.
While the depression appears like a crater in lower resolution wider photographs, higher resolution images suggest it is not round but squarish. Why is not clear, and unfortunately MRO’s high resolution camera has taken no other images of it. This image was also one of their terrain sample photographs, taken not because of any specific research request, but because they need to use the camera regularly to maintain its temperature. This location, having few previous images, fit this schedule and made sense photographing.
Thus, no one appears to be specifically studying this location, making it a ripe subject for some postdoc student who wants to put their name on some Martian geology.
In January 2018 scientists announced the discovery of eight cliffs with visible exposed ice layers in the high mid-latitudes of Mars. At the time, those eight ice scarps were limited to a single crater in the northern hemisphere (Milankovic Crater) and a strip of land in the southern highlands at around latitude 55 degrees south.
In the past two years scientists have been using the high resolution camera on Mars Reconnaissance Orbiter (MRO) to monitor these scarps for changes. So far they have seen none, likely because the changes are below the resolution of the camera.
They have also been able to find more scarps in the southern hemisphere strip beyond that strip at 55 degrees south.
Now they have found more scarps in the northern hemisphere as well, and these are outside Milankovic Crater. As in the south, the new scarps are still all along a latitude strip at about 55 degrees.
The map above shows with the black dots the newer scarps located in the past two years. The scarp to the east of Milankovic Crater is typical of all the other scarps, a steep, pole-facing cliff that seems to be retreating away from the pole..
The scarp to the west of Milankovic Crater is striking in that it is actually a cluster of scarps, all inside a crater in the northern lowland plains. Moreover, these scarps are more indistinct, making them more difficult to identify. According to Colin Dundas of the U.S. Geological Survey’s Astrogeology Science Center in Arizona,
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Cool image time! Using both Martian orbiters and rovers scientists are increasingly convinced that Mars has lots of buried glaciers in its mid-latitudes. These glaciers are presently either inactive or shrinking, their water ice sublimating away as gas, either escaping into space or transporting to the colder poles.
The image to the right, cropped and reduced to post here, shows some apparent proof of this process. Taken by the high resolution camera of Mars Reconnaissance Orbiter (MRO) on December 23, 2019, it shows a weird meandering ridge crossing the floor of a crater. The north and south parts of the crater rim are just beyond the cropped image, so that the gullied slope in the image’s lower left is actually a slope coming down from that rim.
My first reaction upon seeing this image was how much that ridge reminded me of the strange rimstone dams you often find on cave floors, formed when calcite in the water condenses out at the edge of the pond and begins to build up a dam over time.
This Martian ridge was certainly not formed by this process. To get a more accurate explanation, I contacted Dan Berman, senior scientist at the Planetary Science Institute in Arizona, who had requested this image. He explained:
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Cool image time! The science team for the high resolution camera today posted a new captioned image, cropped by me to the right to post here, showing an active Martian dust devil as it moves across the surface of Mars.
Dust devils are rotating columns of dust that form around low-pressure air pockets, and are common on both Earth and Mars. This Martian dust devil formed on the dust-covered, volcanic plains of Amazonis Planitia. The dust devil is bright, and its core is roughly 50 meters across. The dark streak on the ground behind the dust devil is its shadow. The length of the shadow suggests the plume of rotating dust rises about 650 meters into the atmosphere!
That’s about 2,100 feet tall, almost a half mile in height. The location, Amazonis Planitia, is part of the northern lowlands of Mars, flat and somewhat featureless. It is also somewhat near the region near Erebus Montes that is the candidate landing site for SpaceX’s Starship rocket, a region that appears to have a lot of ice just below the surface.
The science team also linked to a 2012 active dust devil image that was even more spectacular. I have also posted on Behind the Black a number of other dust devil images, highlighting this very active, dramatic, and somewhat mysterious aspect of the Martian surface:
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Cool image time! The photo on the right, cropped and reduced to post here, was taken by the high resolution camera of Mars Reconnaissance Orbiter (MRO) on November 30, 2019. It shows a lone crater on the flat northern lowlands of Mars in a region dubbed Arcadia Planitia.
The crater is intriguing because of its concentric ridges and central pit. As this region is known to have a great deal of subsurface water ice, close to the surface, these features were probably caused at impact. My guess is that the ice quickly melted, formed the kind circular ripples you see when you toss a pebble in a pond, but then quickly refroze again, in place.
This location is also of interest in that is it just north of the region that SpaceX considers the prime candidate landing site for its Starship manned spaceship.
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Cool image time! The image to the right, cropped to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on November 15, 2019 during the height of the Martian summer in the northern hemisphere. It shows the scarp of the polar ice cap, looking directly down that scarp at what the MRO image post dubs an “exposure of basal unit”, or the bottom of the cap itself. This suggests that the base of that cliff is no longer ice, but the bedrock below it. If this cliff is similar to other scarps off the polar ice cap it should be at least 1,600 feet tall. It might be more, however, as the elevation difference between the cap and the floor of this basin is estimated by scientists to be more than a mile total.
This scarp however is different than the outer icecap scarps where avalanches occur with great frequency during the spring and summer. Instead, it is located in the heart of the ice cap, at the very end of the gigantic canyon Chasma Boreale that slashes a deep cut into that ice cap, practically cutting it in half.
The overview map on the right, with the red dot showing where this image is located, illustrates the cutting nature of Chasma Boreale. The canyon itself is 350 miles long with a width of about 75 miles at its beginning and with walls that at some points rising a mile in height.
Scientists theorize this canyon was formed by melting ice from cap that built up at the cap’s base, causing erosion and collapse, with the flow following the grade down hill from this end point out to the lowland plains beyond. It is also possible winds played a part in this process, encouraging the canyon formation.
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Cool image time! The photo on the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on October 27, 2019. It shows a dramatic lava flow coming off the flanks of the giant volcano Elysium Mons, a flow that has probably been frozen in place for somewhere between 600 million to 3.4 billion years.
If you look close you can see several craters on top of the lava flow. To my eye these impacts look like they occurred when the lava was still soft, which suggests they were debris thrown up by the volcano. This however would be surprising, as the eruption of Elysium Mons is not thought to have been explosive, but slow and steady. Either way, these crater impacts are one of the ways scientists have been able to estimate the age of this volcano and its long frozen flows.
MRO has taken a scattering of high resolution images in this area, all of which are aimed at similar frozen flows coming off the volcano. All are about 250 miles from the caldera, which gives you a sense of the size and extent of Elysium Mons. While it is the fourth largest volcano on Mars at 7.5 miles high, its grade is so gentle that if you were standing on the surface the peak would be hard to see from any point.
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The science team for the high resolution camera on Mars Reconnaissance Orbiter (MRO) today posted a nice lesson on what features to look for when you are trying to find glaciers on Mars.
To do this they used one of the earliest images of a Martian glacier, taken by MRO on June 12, 2008. The image to the right, cropped and reduced to post here, shows that entire glacier, coming off a mesa in the chaos terrain region of Protonilus Mensae, a region of mesas and glaciers that I highlighted in an earlier post in December, showing images of a mesa that had numerous glaciers flowing down from all sides.
The overview map to the right shows the location of both that earlier glacier-surrounded mesa (the red dot in Protonilus Mensae) and today’s image (the blue dot).
What the MRO science team has done with the image today however is to use it to illustrate the most important geological features that one will see when looking at a Martian glacier.
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