Tag: Mars

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Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on May 30, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label “Patching Mantling Unit,” located at about 57 degrees south latitude in a region where scientists have found good evidence of near surface ice. The top layer, or mantle, is likely patchy because it has a high content of water ice and is sublimating away. That almost all the cliffs are south-facing, which in the southern hemisphere gets the least direct sunlight, supports this supposition. For example, in the crater at the bottom of the image the ice would have disappeared first from the north-facing interior rim slopes, with the sublimation slowly working its way northward. Thus we have that butte extending out from the north rim.

The global map below not only indicates the location of these scallops with the green dot, it illustrates the overall icy nature of most of the Mars.
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Cool image time! The photo to the right, cropped to post here, was taken on May 21, 2022 and was today’s picture of the day from the high resolution camera on Mars Reconnaissance Orbiter (MRO). Dubbed “An Elongated Collapse Pit” by the science team, their caption explains:

This observation can help to tell whether or not there is a subterranean connection to this pit. As an added bonus, the much smaller depression to its south also appears to be another collapse pit.

This image had already been in my queue for a future cool image post, but since the scientists have posted it, it is time that I did as well.

In the inset I have brightened the image drastically to try to illuminate the darkest spots in both pits. The elongated pit appears to slope downward towards a hole in the southeast corner, while the interior of the second pit to the south remains completely dark. Both appear to suggest a void below that both reach.

The wider context image and overview map below shows that there is further evidence of more voids in this region of Mars, dubbed Ceraunius Fossae, because of its many north-south parallel fissures.
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Cool image time! The photo to the right, cropped and reduced to post here, was taken on January 1, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and shows one of the peaks of a 5,000+ foot high mesa inside Juventai Chasma, one of Mars’ deep mostly-enclosed chasms north of Valles Marineris.

I grabbed this picture because its label, “Bedform Change Detection in Juventae Chasma”, suggested something had changed from past photos, probably related to the sand dunes that hug the upper slopes of this peak. Unfortunately, in comparing this image with the earliest high-res image taken by MRO back in February 2018, I could not spot any change, probably because the resolution of the pictures released is not as high as MRO’s raw images.

However, the caption written for that 2018 image tells us where that change has likely occurred:

This image reveals a unique situation where this small dune field occurs along the summit of the large 1-mile-tall [mesa] near the center of Juventae Chasma. The layered [mesa] slopes are far too steep for dunes to climb, and bedform sand is unlikely to come from purely airborne material. Instead, the mound’s summit displays several dark-toned, mantled deposits that are adjacent to the dunes and appear to be eroding into fans of sandy material.

In other words, somewhere in the full resolution image scientists have spotted a change in the bedform sands that make-up these high mountain dunes that hug the peak. Since the data so far has suggested that the source for the sand of these high elevation dunes likely comes from the mesa itself — not from any distant source — any change found will help confirm or disprove that hypothesis.

The white box indicates the area covered by the close-up higher resolution picture below. Also below is an overview map, showing both the location of this mountain in Juventai Chasma as well as Juventai’s location relative to Valles Marineris.
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Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on February 17, 2012 by the wide-view context camera on Mars Reconnaissance Orbiter (MRO). It shows a section of the northern lowland plains of Mars, latitude 31 degrees north, where several very inexplicable and isolated ridges can be seen.

One ridge meanders mostly in a north-south direction, while a second instead meanders east-west. The shape of both says that neither has anything to do with any past impact crater. In fact, their random snakelike shape doesn’t really fit any obvious explanation. For example, they do not fit the look of the many fossil rivers found on Mars, where the hardened and dry riverbed channel resists erosion and becomes a ridge when the surrounding terrain erodes away.

What geological process caused them? In the decade since this photo was taken the scientists who use MRO have only been able to snap a handful of high resolution images of these ridges. The image below is the most recent, covering the area in the white rectangle above.
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Cool image time! The photo to the right, cropped and reduced to post here, was taken on January 2, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Simply labeled “slope features,” it was likely taken to monitor the gullies and streaks on the interior walls of this 4-mile-wide crater. Scientists have been using MRO to track the coming and going of frost on this crater’s interior walls since 2016.

Equally intriguing however are what appear to be squashed layers within the crater’s interior. These appear to be some form of glacial feature created by repeated climate cycles, similar to the glacial features routinely seen throughout the 30 to 60 degree mid-latitude strips north and south.

What makes the glacial features in this particular crater particularly intriguing is its location, as shown in the overview map below.
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Cool image time! The photo above, rotated, cropped, and reduced to post here, was taken on March 5, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as a “viscous flow feature,” which is another way of saying the flow was thick and syrupy.

Nor is such a flow unusual in this area of Mars. It is located in a region of chaos terrain dubbed Protonilus Mensae, which is also the central mensae region in the 2,000-mile-long strip in the northern mid-latitudes of Mars I label glacier country. The overview map above of Protonilus Mensae — covering about 500 miles in width — shows how common such flows are in this place. The black rectangles mark the locations of other cool images I have featured, as follows:

• 1. Buried glaciers flowing off of Martian mesa
• 2. Brain Terrain on Mars
• 3. How to spot a glacier on Mars
• 4. Glacier country on Mars
• 5. Revisiting Mars’ glacier country
• 6. Back to Mars’ glacier country
• 7. A cracking Martian glacier?
• 8. Ice-filled craters in Mars’ glacier country?

The red rectangle indicates the location of today’s cool image.

The glacial aspect of everything in this region is even more emphasized by the wider view provided by MRO’s context camera below.
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Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on November 22, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team labeled a sinuous ridge. Make sure you also look at the full image. The ridge goes on to the south, but then fades way as an almost perfect ramp, only to have another even more wiggly but thinner north-south ridge begin only a few feet to the west.

Sinuous ridges like this are found in many places on Mars. Almost always their origin is thought the result of a former river channel that became a ridge when the surrounding softer material eroded away.

That explanation however does not seem to work for this ridge. It has too many other inexplicable features. For example, note how the peak of the ridge smoothly transitions from sharp to flat-topped. It has a soft appearance that is strengthened by the gap near the top.

It is almost as if this ridge is a kind of elongated sand dune! And guess what: The overview map below gives that explanation some believability.
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In our third Martian cool image of the day, we go to the north pole of Mars, as seen from orbit by the high resolution camera of Mars Reconnaissance Orbiter (MRO). Taken on March 30, 2022 and cropped and reduced to post here, this picture shows some of the distinct and unique geological features found only on the polar caps of Mars. From the caption by Candy Hansen of the Planetary Science Institute in Tucson, Arizona:

Both water and dry ice have a major role in sculpting Mars’ surface at high latitudes. Water ice frozen in the soil splits the ground into polygons. Erosion of the channels forming the boundaries of the polygons by dry ice sublimating in the spring adds plenty of twists and turns to them.

Spring activity is visible as the layer of translucent dry ice coating the surface develops vents that allow gas to escape. The gas carries along fine particles of material from the surface further eroding the channels. The particles drop to the surface in dark fan-shaped deposits. Sometimes the dark particles sink into the dry ice, leaving bright marks where the fans were originally deposited. Often the vent closes, then opens again, so we see two or more fans originating from the same spot but oriented in different directions as the wind changes.

The top layer of translucent dry ice falls as dry ice snow during the winter, than sublimates away with the arrival of spring. Since this photo was taken in autumn, we are looking at features left over from the activity from the spring and summer.