Tag: spaceflight

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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 on November 30, 2019. Located just east of Hellas Basin in southern mid-latitudes, the color strip shows dry ice frost both in the crater as well as on the ridgelines to the north. As noted in the caption, written by Candy Hansen of the Planetary Science Institute in Tucson, Arizona,

When we acquired this image, it was [winter in the southern hemisphere] on Mars, but signs of spring are already starting to appear at latitudes not far from the equator. This image of Penticton Crater, taken at latitude 38 degrees south, shows streamers of seasonal carbon dioxide ice (dry ice) only remaining in places in the terrain that are still partially in the shade.

The turquoise-colored frost (enhanced color) is protected from the sun in shadowed dips in the ground while the sunlit surface nearby is already frost-free.

Note for example how the frost disappears in the southern half of the crater floor, the part exposed to sunlight.

What immediately struck me however were the underlying features. The entire northeast quadrant of the crater’s rim appears to have been breached by some sort of catastrophic flow, as if there had been a glacial lake inside the crater that at some point smashed through suddenly, wiping that part of the rim out as it ripped its way through.

To the right is a full resolution inset, indicated by the white box above, of the dry ice frost on the outside of the crater. I find myself however drawn more to the underlying features, which once again have a chaotic aspect suggesting a sudden violent event, coming from the south and moving north.

I have no idea if my visceral conclusions here have any validity. At this latitude, 38 degrees, scientists have found a lot of buried inactive glaciers of ice, so I could be right. Or not. Your guess is as good as mine.

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Cool image time! If we were told that the photo on the right was taken by an airplane over some southwest desert gully, no one should be surprised if we were to accept that description entirely. The gully sure looks like a lot of drainages one can routinely see when flying over the American southwest, dry, treeless, but showing the typical dendritic pattern seen for most desert water drainages.

Of course my readers all know that this is not in the American southwest, but on Mars, in a crater located in the transition zone between the southern highlands and the northern lowland plains. The image, cropped to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter on October 12, 2019.

It appears that this particular gully has been subject to repeated monitoring, since November 2015. A rough and very quick comparison of the earlier image with today’s image does not show any obvious change. This does not mean there hasn’t been any evolution, as my look was cursory, and I could easily be missing changes. Seasonal variations might also be occurring that I could be missing.

The reasons for the monitoring are of course obvious. This gully strongly suggests the flow of liquid downhill. Is that occurring today, or are we seeing the evidence of a past flow from long ago? Only some long term monitoring can tell.

There is also the possibility that we are looking at a buried glacier. The crater is located at 42 degrees north latitude, well within that mid-latitude band where scientists have located many buried Martian glaciers. If so, then the monitoring is to see if that glacier is active in any way.

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Cool image time! The photo on the right, cropped and reduced to post here, shows a cluster of really strange mesas, craters, and pits, located in Utopia Planitia, the largest and deepest plain of Mars’ northern lowlands where an intermittent ocean might have once existed.

The image was taken on October 26, 2019 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) as part of its regular image-taking program. In this case it was dubbed a “terrain sample” image, meaning that it was not specifically requested by any researcher, but was taken because they need to use the camera regularly to maintain its temperature, and thus sometime produce images over previously untouched areas, not knowing what they will find, as part of that maintenance schedule.

In this case the terrain sampled is especially intriguing. Are the upraised depressions what are called pedestal craters, created when the impact landed on what was once an icy plain, which subsequently sublimated away to leave the crater sitting high above the surrounding flats? Maybe, but this location is at 23 degrees north latitude, and research has generally found these pedestal craters at latitudes higher than 30 degrees.

Moreover, that many of these upraised depressions are not circular suggests that their formation was not impact related.

Other mysteries: Why are all the ridgelines bright? What caused the parallel white streaks to the east and west of some mesas? And if these are impact craters, why are some distorted?

If this region was once the seabed of an intermittent ocean, this fact might explain the features. Then again, it is more likely that this lowland area was once covered in ice in the far past, when the planet’s tilt was greater and the lower latitudes were actually colder than the polar regions, and thus allowed ice to build up in those lower latitudes. We might therefore be seeing the end result of an erosion/sublimation process as that ice disappeared when Mars’ inclination shifted.

Lots of questions, and no answers.

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It’s a slow news week, with the too much partying only real space news today the expected third launch of China’s Long March 5 rocket (supposedly scheduled for this morning but so far no word). (To my gentle reader: For some reason I have been losing a day during this whole week, always thinking that Christmas was on Thursday and that today was Friday. Thus my error in thinking the Long March 5 flight was today. It is tomorrow morning. Forgive me for my absent-mindedness.) So let’s look at a cool image!

The photo on the right, cropped and reduced to post here, was taken my the high resolution camera on Mars Reconnaissance Orbiter (MRO) on October 8, 2019. Entitled “Scalloped Depressions in Utopia Planitia,” it shows a strangely eroded surface in the northern lowlands of Mars, where an intermittent ocean might have once existed.

The location of these scallops is shown to the right.

I have taken the same overview map used from two recent cool image posts, showing how these scallops relate in location to the strange crater in Utopia Planitia as well as the glacial-surrounded mesa in Protonilus Mensae.

In caves, scallops like this form from water or wind flow, but when they do, they are all oriented the same way. Here the scallops are at different orientations, terracing down from the center of the image. In this case it appears that scientists believe [pdf] the formation process is related to the sublimation of underground ice at this location.

According to [one hypothesis] scallop formation should be ongoing at the present time. Sublimation of interstitial ice could induce a collapse of material, initially as a small pit, then growing southward because of greater solar heating on the southern side. Nearby scallops would coalesce together as can be seen to have occurred.

What is most cool is that the geologists think the process that forms these scallops is related to the same processes that cause the formation of the swiss cheese landforms in the south polar regions.