Tag: Jezero Crater

Our second cool image takes us from grand galaxies, one of the universe’s largest coherent objects, to tiny cobbles on Mars. The picture to the right, taken by one of Perseverance’s close-up cameras on September 29, 2022, covers an area less than an inch across, making the largest rounded pebbles in this image only a few millimeters in size.

The rover presently sits on the floor of Jezero Crater, at the base of the delta that flowed into that crater eons ago. The data suggests that delta was created by flowing water entering a lake that filled the crater.

Did flowing water create these cobbles? These pebbles all have the look of the rounded cobble one finds either in river beds, or in glacial moraines. In both cases, the flow of the water or ice rolls the rocks along until they become rounded.

Two new papers (here and here), published last week in Science and using data obtained during Perseverance’s first year of roving on Mars, strongly suggest that the floor of Jezero Crater was first formed by lava flows, either from impact or later flows from eruptions, followed by a period where liquid water interacted with these igneous materials to produce the chemistry seen today. From the first paper:

After emplacement of the igneous rocks on the crater floor, multiple forms of aqueous interaction modified—but did not destroy—their igneous mineralogy, composition, and texture. Evidence for alteration includes the presence of carbonate in the Séítah abrasion patches, the iron oxides in the Máaz formation abrasion patches (which we presume are due to iron mobilization and precipitation), and the deposition of salts including sulfates and perchlorate. More broadly, the appearance of possible spheroidal weathering textures suggests that aqueous alteration played a role in rock disintegration.

The graphic to the right, figure 6 in the first paper, shows two different models for the geological formation of the floor of Jezero Crater. “Basalt emplacement” are the lava flows.

According to the press release today [pdf], the first core samples that the rover gathered for later pickup and return to Earth will likely show the following:

The salts include sulfates, similar to Epsom salts, which are common on Mars. Most importantly, high levels of chlorine-containing salts are also present, such as chlorides (“table salt”) and perchlorates. These highly soluble salts reveal that the rocks were soaked in brines, and hence contain clear evidence of liquid water.

The on-going big geological mystery of Mars remains. The data suggests liquid water once existed as some form in Jezero Crater. Other data suggests liquid water existed elsewhere on Mars as well. Yet, no model exists that anyone accepts with any confidence that makes it possible for liquid water to exist on the Martian surface. Its atmosphere has always been either too cold or thin.

To underline this conundrum, note that in the graphic above, neither model includes a time period when liquid water sat on top of these layers. Though the evidence calls for liquid water at some time, the scientists do not feel confident enough to include it in these initial models.

One possible explanation that I sense some scientists are beginning to consider is the chemical interaction of melted ice at the base of past long gone ice glaciers. The ice would be frozen, but the glacier’s movement might create pockets of liquid water at its base, which over eons might result in these chemical reactions. If Jezero Crater had once been filled with glaciers, as many Martian craters in the mid-latitudes appear to be now, this could have provided the water necessary for the chemical modifications the scientists are finding.

This theory however is entirely speculative on my part, and has not yet been proposed by any scientists, though I have seen hints of it in a number of different research papers.

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Cool image time! The photo to the right, cropped, reduced, and enhanced to post here, was taken on August 17, 2022 by one of Perseverance’s high resolution camera. It shows the exposed layers of a nearby cliff face that comprises the end of the delta that once flowed into Jezero Crater in the distant Martian past.

My guess is that this cliff is about 20 feet high. The more massive, thicker and younger layers near the top, compared to the thinner and older layers below, suggest a major change in the cyclic events. The early cycles that lay down this delta were initially shorter and able to place less material with each cycle, while the last few cycles were longer, producing thicker layers.

The difference in layers also strongly suggests that all the blocks at the foot of the cliff fell from more massive layers at the top. Material that broke off from the lower thinner layers has likely long ago eroded away.

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Since August 5th, the Perseverance science team has been trying to figure out the origin as well as the consequences of “two string-like pieces” of foreign object debris (FOD as used by today’s acronym-happy scientists) that they have spotted next to one of the rover’s coring drill bits.

The photo to the right, cropped and reduced to post here, looks directly down at that core drill bit and shows one of those strings both to the side of the bit as well in full resolution in the inset. From today’s update:

Since first identified Aug. 5 in imagery of the rover’s sample collection system after a 12th rock core sample was taken, the FOD has been the focus of several methodical diagnostic activities in an attempt to better understand the nature of the debris.

We’ve commanded the rover to move, rotate, or vibrate components we think could harbor FOD. And we’ve obtained multiple sets of images of the components from different angles and in different lighting conditions from rover cameras: Mastcam-Z, Navcam, Hazcam, Supercam, and even the WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) camera located on the rover’s turret. Finally, a thorough review of recent coring and bit-exchange activities confirm that they all executed nominally with no indication of interference from the FOD.

Analysis of the latest round of imaging, downlinked earlier today, indicates that while the two small pieces remain visible in the upper part of the drill chuck, no new FOD has been observed. In addition, imagery taken of the ground beneath the robotic arm and turret, as well as the rover deck, also showed no new FOD.

Because these strings do not appear to interfere in any way with the drill’s operation, the science team has decided neither is a cause for concern, and will therefore command the rover to leave this just-completed drill site and move on to the southwest to a location at the base of the delta the rover visited about three months ago.

The strings themselves are likely pieces from the equipment released during the rover’s landing, and might even have come from the tangled string the rover imaged on the nearby ground in July, and that was gone just four days later. The wind had blown it away, and may have even at that time blown pieces into the drill.

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The Perseverance science team today posted a detailed update on the various pieces of debris that both the rover and the Ingenuity helicopter have been tracking since both landed on Mars in February 2021.

Some of the EDL [entry, descent, landing] hardware broke into smaller pieces when it impacted the surface. These pieces of EDL debris have been spotted in images of the Hogwallow Flats region, a location roughly 2 km to the northwest of the EDL hardware crash zones. As of Sol 508 (July 24, 2022), the operations team has catalogued roughly half a dozen pieces of suspected EDL debris in this area. Some of these EDL debris are actively blowing around in the wind. So far, we’ve seen shiny pieces of thermal blanket material, Dacron netting material that is also used in thermal blankets, and a stringlike material that we conclude to be a likely piece of shredded Dacron netting.

To the right are two of the most interesting examples. The top image shows the parachute and associated equipment from the landing, taken by Ingenuity during a flight in April 2022. That image, when compared with an earlier picture taken from orbit, showed that the wind of Mars, though incredibly weak, had been able to shift the parachutes edges.

The second image shows the string that the rover photographed on July 12, 2022, and had blown away four days later when Perseverance re-photographed this site.

Today’s update notes that the area in the crater they have dubbed Hogwallow Flats “appears to be a natural collecting point for windblown EDL debris.” The flats are an area at the foot of the delta that flowed into Jezero Crater in the past, and is an area where Perseverance has been traveling most recently.

That the wind has been able to move small pieces so effectively is I think somewhat of a surprise. That it is gathering the material against the crater’s western cliffs suggests the prevailing winds here blow to the west.

For originals go here, here, and here.

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Cool image time! The mosaic to the right is made up of three images produced by the high resolution camera on the Mars rover Perseverance (found here, here, and here). All three were taken on July 24, 2022 and look north to the nearest cliff face at the head of the large delta that flowed into Jezero Crater some time in the distant past.

The rover was about 80 feet away from the feature when the photo was snapped. Though scale in the photo is not provided, using the scale in the overview map below I would guess this slot canyon is several feet wide, with some spots narrow enough that your body would touch both walls at spots. Its height is likely nor more than 20 feet high, at the very most.

On the overview map, the blue dots mark Perseverance’s location, in both the main map and the inset. The green dot marks where the helicopter Ingenuity presently sits. The red dotted line is my guess as to the future route of the rover up into the delta. The yellow lines indicate the area viewed in the mosaic.

Though hardly as deep as the many slot canyons found in the American southwest, that this slot exists on Mars is quite intriguing. Did it form like those southwestern slots from water flow? Probably not. More likely we are looking at a fracture produced by shifts in the entire delta itself, and then later widened by wind.

That the cliff shows multiple layers suggests the delta was laid down in multiple events, and that the fracture occurred after the delta was emplaced. That the layers on either side of the fracture appear to match up strengthens this conclusion. These layers also suggest that the layering is not simply in a series of small events. The layers are also grouped into larger aggregates, suggesting those larger groupings mark longer epochs, each with its own unique conditions.

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Cool image time! The photo above, cropped and reduced to post here, was taken on July 20, 2022 by one of high resolution cameras on the rover Perseverance. It shows what appears to be a collapsed dune on the floor of Jezero Crater.

The arrows mark the highest dune ridge line that suddenly ends at a cliff, with the sand that is piled up at its base appearing almost like it flowed like thick mud outward away from that cliff. Apparently, that material broke off in one single event sometime in the past.

Note the many parallel lines pointing outward from the base of the cliff. These lines appear to reflect the internal structure visible in the cliff itself. Somehow, when that sand collapsed, it flowed away while retaining some of that structure.

When this collapse happened is unclear. I don’t think it has happened recently, since Perseverance’s arrival, but I could be wrong.

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Cool image time! The photo above, rotated and cropped to post here, was taken on July 18, 2022 by the right navigation camera on the Mars rover Perseverance.

The view isn’t that remarkable, when compared to many other pictures from Mars. What makes it newly interesting is that it shows that Perseverance has gained a little elevation as it explores the base of the delta that flowed into Jezero Crater. It is no longer on the crater floor, but above it, though not by much.

You can see the far rim of Jezero Crater in the distance, obscured somewhat by the dust that builds up in the Martian atmosphere during the winter. You can also see the gentle left-to-right downward slope of material that flowed down from that delta some time in the past. Also, though the resolution isn’t good enough to show it, the helicopter Ingenuity probably sits somewhere near the center of this picture, just to the right of the nose of the biggest ridgeline.

The overview map on the right gives the context, with the yellow lines showing my estimate of the area viewed by the picture above. The blue dot is Perseverance, the green dot is Ingenuity. The red dotted line is my present guess as to the planned route of Perservance up onto the delta.

According to the principal investigator for Perseverance’s two wind sensors, one was recently damaged by a wind-blown tiny pebble.

Pebbles carried aloft by strong Red Planet gusts recently damaged one of the wind sensors, but MEDA can still keep track of wind at its landing area in Jezero Crater, albeit with decreased sensitivity, José Antonio Rodriguez Manfredi, principal investigator of MEDA, told Space.com. “Right now, the sensor is diminished in its capabilities, but it still provides speed and direction magnitudes,” Rodriguez Manfredi, a scientist at the Spanish Astrobiology Center in Madrid, wrote in an e-mail. “The whole team is now re-tuning the retrieval procedure to get more accuracy from the undamaged detector readings.”

…Like all instruments on Perseverance, the wind sensor was designed with redundancy and protection in mind, Rodriguez Manfredi noted. “But of course, there is a limit to everything.” And for an instrument like MEDA, the limit is more challenging, since the sensors must be exposed to environmental conditions in order to record wind parameters. But when stronger-than-anticipated winds lifted larger pebbles than expected, the combination resulted in damage to some of the detector elements.

The term “pebble” implies a larger-sized particle than what probably hit the sensor. I suspect the “pebble” was no more than one or two millimeters in diameter, at the most.

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Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera on the Mars rover Perseverance on June 16, 2022, shortly after it began its first climb up from the generally flat floor of Jezero crater and onto the delta that once in the far past flowed through a gap into that crater.

I have rotated the image about 8.5 degrees to make horizontal the crater floor and the distant rim of the crater (barely visible through the atmosphere’s thick winter dust). This shows that the rover was then climbing what appears to be a relative low angle grade, hardly as challenging as the serious grades that Curiosity has been dealing with now for the past two years in the foothills of Mount Sharp. Nonetheless, Perseverance has begun climbing.

To see where the rover is see the overview map from the start of this week. Unfortunately, I have been unable to determine the direction of this photo. It could be looking west, south, or east, based on features inside Jezero Crater. I therefore cannot tell you the distance to the rim, which depending on the direction, could be from five to twenty-five miles away.

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In our second cool image from Mars today, the Mars rover Perseverance gives us its own long distance view of the dusty winter air inside Jezero Crater. The photo above, cropped and reduced to post here, was taken on June 16, 2022 by the rover’s left high resolution camera, and looks to the southwest towards the crater’s western rim.

As with today’s previous cool image from Curiosity, we can see several ranges, each with distance faded more by the dust that hangs in the air during the winter on Mars. In the foreground right is the nearest cliff of the delta that flowed into Jezero over time in the past. Next is a knob and ridge line, also part of that delta flow but farther away. Third are some farther ridges that might have been part of that flow but maybe not.

Faintest of all are the highest mountains that form the western ridge of Jezero Crater, barely visible in the haze.

The blue dot in the overview map to the right marks Perseverance’s approximate position when the photo was taken. The yellow lines my guess as to the area covered by the photo. The green dot marks Ingenuity’s present position after its last flight, much closer to the delta that I had predicted.

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Time for some cool images from Perseverance! The rover, now on Mars for more than a year, has finally begun its journey up the delta of material that some time in the past flowed through a gap in the rim of Jezero Crater. In doing so, it has also finally got close to a nearby cliff, within fifty feet or so, and used its high resolution left mast camera (mastcam) to take the photos to the right. The first, cropped and reduced to post here, was a wider shot taken on June 10, 2022, with the red arrow pointing to the part of the cliff featured in the second image below, taken on June 12, 2022, after the rover had moved in closer. This second photo is also cropped and reduced to post here.
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Since early February the Mars Rover Perseverance has been toting with it a small rock in its front left wheel, as shown in the image to the right, cropped and reduced to post here and taken by the rover’s left hazard avoidance camera on February 6, 2022.

From an update today by the Perseverance science team:

Back on sol 341— that’s over 100 sols ago, in early February— a rock found its way into the rover’s front left wheel, and since hitching a ride, it’s been transported more than 5.3 miles (8.5 km). This rock isn’t doing any damage to the wheel, but throughout its (no doubt bumpy!) journey, it has clung on and made periodic appearances in our left Hazcam images.

You can see the most recent photo of the rock, taken on May 26, 2022, here. It is very clear that the rock’s repeated tumbling inside the wheel well has worn away its sharp edges as well as reduced its overall size. Given enough time its surface could even become somewhat smooth.

As the update notes, when this rock finally drops off it will create a potential mystery for future geologists, who if they are not aware that Perseverance moved it, will wonder how it got where it was, being geologically out-of-place in its new location.

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Today’s update from the Perseverance’s science team provided a rough outline of their travel and drill-sampling plans for the Mars rover in Jezero Crater as it begins its climb up onto the delta that once poured into the crater. The route they plan to travel initially is dubbed Hawksbill Gap.

At Hawksbill Gap, however, we may instead carry out the first portion of the sampling sol path (which includes abrasion and collecting observations using our proximity science instruments) at up to 5 locations along our ascent. After that, we’ll turn around and begin a descent back down Hawksbill Gap and collect rock core samples at 3 of our abrasion locations.

This modified sampling strategy is intended to provide the team with valuable contextual information as we climb Hawksbill Gap and interpret the delta stratigraphy around us. With proximity science data in-hand, we can down-select our sampling sites to ensure we’ll be collecting the most scientifically valuable cores along our descent. Of course, we still maintain the option of collecting sample cores at any point during our ascent, if the team decides a particular abrasion site warrants immediate sampling.

The map above shows my guess (the red dotted lines) as to their potential routes uphill. As the science team has so far not published a map indicating exactly where Hawksbill Gap is, I can only guess at this point. The blue dot indicates Perseverance’s present position, the green dot Ingenuity.

As for the helicopter, there is no word yet whether the engineers have successfully gotten its batteries back to full charge. Until then, it cannot fly, and is also at risk of freezing up in the cold Martian winter.