Tag: Mars Reconnaissance Orbiter

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Cool image time! The image to the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on December 15, 2020, and was actually a follow-up observation from an earlier image taken by the camera on Europe’s Trace Gas Orbiter (TGO), according to Dr. Livio Tornabene of the University of Western Ontario. As he explained in an email:

The team is rather polarized with their verdict on what exactly the feature is… while at first glance it appears to be a lava flow, it very well could be that these deposits eroded to yield this flow/lobate like appearance and isn’t lava at all. So as someone that is both involved with [TGO] and [MRO], I noticed that the lobate feature causing quite the debate had no coverage from [MRO].

It appears that some scientists think that instead of lava, this is a mud flow. Research presented [pdf] during the 2019 Lunar & Planetary Conference in Texas found evidence that mud could flow like lava under the right conditions.

At this point neither Tornabene nor anyone working on the TGO team have yet analyzed this new MRO image to see if they can answer this question. That this feature is located in a region just to the southeast of Marineris Valles where there is evidence both of volcanic activity and sedimentary deposition, makes answering the question even more challenging.

The data from TGO indicated [pdf] that the plateau was about 30 to 65 feet thick. Based on crater counts the age is thought to be between 1.6 to 1.9 billion years old.

What struck me about the plateau is that though it really does look like a flow, it also appears remarkably flat and smooth. Even more puzzling is that, according to the TGO paper, the plateau slopes downhill very gently (a 1% grade) to the south, not to the north as suggested by the shape of the flow. Maybe later geological events tilted the entire feature after it solidified, thus changing the grade?

Meanwhile that channel near the bottom of the image crosses through the grade and the flow, as if it was cut after the flow was placed. In other words, the flow and channel were formed separately, at different times.

Ah, the mysteries of planetary geology. If only we could just go there with a geologist’s hammer. These questions would then be so much more simple to answer.

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In doing my normal exploration through the monthly download of new images from the high resolution camera on Mars Reconnaissance Orbiter (MRO), the last to occur near the end of February, I came across a slew of 49 images, each labeled as an “ADC Settings Test,” each covering a completely different location with no obvious single object of study, almost as if they were taken in a wildly random manner.

The image to the right, cropped and reduced to post here, is a typical example. It shows the mega dunes located near the end of the canyon Chasma Boreale that cuts a giant slash into the Martian north polar ice cap, almost cutting off one third of the icecap.

The black areas are shadows, long because being at the high latitude of 84 degrees the Sun never gets very high in the sky, even though this image was taken just before mid-summer, when the Sun was at its highest.

I was puzzled why these images were being taken, and contacted Ari Espinoza, the media rep for the high resolution camera, to ask if he could put me in touch with a scientist who could provide an explanation. He in turn suggested I contact Shane Byrne of the Lunar and Planetary Lab University of Arizona, who coincidentally I had already spoken with several times before in connection with the annual summer avalanche season at the Martian north pole.

Dr. Byrne first suggested I read this abstract [pdf], written for the 2018 Lunar and Planetary Science conference by the camera’s science team. In it they outline two issues with the camera, one blurred images and the second an increasing number of bad pixels occurring in images over time.

The first problem has since been solved. To preserve battery life — another long term problem that they have to deal with — they had adjusted the orbiter’s orbit slightly to get more sunlight and stopped warming the camera during the night periods. “That had the unfortunate effect of changing the camera’s focus,” explained Byrne. “Since we understand that now, we do warm-ups before taking the images and that fixed the blurring problem.”

The other problem however remains, and these ADC test images are an effort to fix it.
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Cool image time! Or rather, a bunch of cool images! On February 17, 2020 the science team for the high resolution camera on Mars Reconnaissance Orbiter (MRO) released a very cool captioned photograph of a terraced mesa in a crater just north of Hellas Basin, shown in the image to the right, rotated, cropped, and reduced to post here.

The color strip down the center of this image illustrates how the colors of the different layers indicate the different make-up of each. These distinctions are not obvious in black & white. That array of colors also leads to some very beautiful scenery, as noted by planetary scientist Alfred McEwen in his caption:

Sedimentary layers record a history of Mars’ erosion and deposition by water and wind, and they make great landscapes for future interplanetary parks.

That this terraced mesa is located on the northern edge of Hellas Basin, the basement of Mars, is possibly not surprising. Other similarly terraced mesas like this have been found on the basin’s eastern edge, highlighted in my September 2019 post. The geology here appears to encourage this kind of erosion, where the different sedimentary bedrock layers erode away at different rates, leaving behind terraced mesas.

Terraced layers on Mars however come in other varieties, some of which build up over time instead of getting eroded away.
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Cool image time! Today the science team for the high resolution camera on Mars Reconnaissance Orbiter (MRO) released a beautiful captioned image of a secondary impact of an object into the icy plains of Utopia Planitia, the northern lowlands northeast of where the rover Perseverance will land in 2021. The image to the right, cropped and reduced to post here, shows one of several secondary craters in the full image. As planetary scientist Alfred McEwen explains in the caption,

One interpretation [for the crater’s unusual appearance] is that the impact crater exposed nearly pure water ice, which then sublimated away where exposed by the slopes of the crater, expanding the crater’s diameter and producing a scalloped appearance. The small polygons are another indicator of shallow ice.

Note the dunes at the bottom of the crater. This has become a trap of wind-blown sand and dust. Note also how this secondary impact gives us a rough idea of the thickness of this ice, based on the area sublimated away.

There is a lot of relatively accessible ice in those northern lowlands, which is why SpaceX likes them for its possible landing site for Starship. That candidate site is in Arcadia Planitia, on the other side of Mars, but it is still in these same northern lowlands, where scientists have found lots of evidence of buried ice.