Tag: geology

Ingenuity completes 21st flight on Mars

3:54 pm

Overview map
Click for interactive map.

According to a tweet today from JPL, the Mars helicopter Ingenuity has successfully completed its 21st flight on Mars, traveling 1,214 feet in two minutes and nine seconds at an average speed of 12.6 feet per second.

The red dot on the map to the right shows Perseverance’s location as of today. The green dot indicates Ingenuity’s position before the 21st flight. Since neither the Perseverance nor the helicopter teams have posted any updates describing the 21st flight, it is difficult to indicate a precise location for its landing site. All we know is that the helicopter is supposed to fly to the northwest, cutting across the rougher region while the rover follows the tan dotted line around that rough region, with both targeting the delta to the northwest.

As a guess, I have placed a black dot about 1,200 feet to the northwest.

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More thumbprints on Mars!

1:22 pm

Thumbprints on Mars
Click for full image.

Cool image time! Among the many strange and unexplained geological features that scientists have identified on Mars, the thumbprint feature is one of the most intriguing. The photo to the right, cropped and reduced to post here, is a fine example, and was taken on September 10, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The thumbprints are the lighter splotches, and are generally found near curved ridges located mostly in Martian lowlands. All appear to have crater-like features in them, though these craters are not impact craters, but likely (though not confirmed) caused by some form of underground eruption, be it mud, ice, lava or something else. Though scientists do not yet really understand the process that formed the thumbprints, the data strongly suggests that they formed in connection with glacial events. From this 2003 paper [pdf]:

TT [thumbprint terrain] as well as the associated trough systems were formed by a glacial mechanism. [Elevation] data show that the trough systems consistently lie topographically above the TT; this implies that if they were they formed by the same glacier, the troughs must have formed before the glacier retreated and formed the TT.

The splash apron around the crater near the bottom of the photo supports the glacial theory, implying the presence here of underground ice.

Scientists have also theorized wind processes and cinder cones as explanations for these features.

These particular thumbprints are located, as shown in the overview map below, in the same general area as a previous cool image of thumbprints, from April 2019.
» Read more

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Monitoring one glacier flowing off a mesa in Mars’ glacier country

1:28 pm

Vicous glacial flow on Mars
Click for full image.

Today’s cool image takes us back to the mesa in Mars’ glacier country that first clued me in on the prevalence of ice in the Martian mid-latitudes. The photo to the right, rotated, cropped, and reduced to post here, was taken on November 13, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows a viscous flow coming down from a hollow on that mesa’s southern wall.

The new image has likely been taken to see if anything has changed since the previous image was taken in 2014. Based on the resolution published at the MRO website, nothing seems to have changed, though with more sophisticated software higher resolution versions of the images are available that might show some changes.

In my first post about Mars’ glacier country in December 2019, this flow was one of four that I featured coming off this same 30-mile wide mesa, as shown by the first overview map below.
» Read more

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Fractured terrain on Mars

1:39 pm

Fractures on Mars
Click for full image.

Today’s cool image, which at first glance does not seem so puzzling, actually falls into my “What the heck?” category of baffling Martian geology. The picture to the right, cropped and reduced to post here, was taken on January 15, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled “Avernus Cavi fractures”, it shows what resembles the well-documented chaos terrain seen in many places on Mars, where erosion over eons along fault lines creates mesas with random criss-crossing canyons.

The problem is that this location is practically on the Martian equator, and chaos terrain tends to be found in the mid-latitude bands where there are many glaciers, suggesting the cyclical waxing and waning of those glaciers is what causes the erosion. Here at the Martian equator the terrain is very dry. No glaciers.

Moreover, note the higher mesa near the top center. Its flat top suggests that once this terrain was covered with an even higher layer of material, almost all of which was stripped away evenly everywhere, except where that mesa sits. As an amateur geologist I can’t think of any sequence of events that would do such a thing. I suspect professionals might have problems themselves.

Then there are the small parallel ridges. They suggest dunes, especially inside the depressions where sand and dust can get trapped. On the mesa tops however these ridges are more mysterious. Why for example are they aligned with the small ridge in some hollows, but not others? They in many ways remind me of the ridges in this earlier “What the heck?” cool image, also right on the equator.

The overview map below provides some help, though not much.
» Read more

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The layered Martian history exposed in Valles Marineris

12:28 pm

Overview map

The layers in Valles Marineris
Click for full image.

Cool image time! Like the Grand Canyon in the United States, Mars’ largest canyon, Valles Marineris, appears to have been carved out of a layered terrain, thus exposing those many layers in the walls of the canyon.

Valles Marineris, however, is much much larger than the Grand Canyon. You could fit dozens of Grand Canyons inside it and hardly fill it. Yet, its walls have the same layered look, suggesting that in Mars’ long geological history, first came many events that laid down new layers time after time, followed by a long period when the laying ceased and other events carved out the canyon to its almost 30,000 foot depth (which by the way is also about six times deeper than the Grand Canyon).

Today’s cool image to the right, cropped and reduced to post here, was taken on September 5, 2021 and shows a terraced terrain on the floor of Candor Chasma, one small side canyon of Valles Marineris that is still much larger than the Grand Canyon. The black dot in the overview map above indicates its location. I roughly estimate the elevation difference between the high and low spots in the picture is about 3,000 feet, a difference that while two-thirds that of the depth of the Grand Canyon is almost unnoticeable within the depths of Valles Marineris.

This layering is probably the canyon’s most important geological feature. See these previous cool images here and here for other examples. When geologists finally arrive on Mars and can begin dating these layers in detail they will likely reveal the planet’s entire geological history, going back five to six billion years.

Most of the layers are probably volcanic flood lava laid down by repeated eruptions from the giant volcanoes to the west. In between and within however will be deposits from the Martian atmosphere, telling us its composition and thickness. All told, the layers of Valles Marineris will likely unlock almost all of the most basic secrets of Martian geology.

We merely have to go there to find out.

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Martian crater overwhelmed by glacier?

1:32 pm

Martian crater overwhelmed by glacier?
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on January 28, 2022 by the high resolution camera on Mars Reconnaissance Orbiter. It shows what the science team labels a “modified crater.”

What I see is an old crater almost completely covered by glacial material. That material however is also very old, as there are numerous small craters on its surface, enough that it must have been here for a long time. Its cracked surface also suggests this glacier is very old.

Thus, while we might have ice here, buried by a thin layer of dust and debris to prevent it from sublimating away, it must be very old ice. The many climate cycles caused by the extreme swings in Mars’ rotational tilt, from 11 to 60 degrees, have apparently not caused this ice to ebb and flow very much.

Might it therefore not be ice, but hardened lava?

The location, as shown by the overview map below, provides some context, but only makes this mystery more puzzling.
» Read more

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Scientists: Yutu-2 spots tiny glass globules similar to those found by Apollo astronauts

9:45 am

According to a paper just published Chinese scientists running the Yutu-2 rover on the far side of the Moon have spotted several tiny glass globules similar to those found by Apollo astronauts.

Xiao and his team believe the small spheres, which are between 0.59 and 0.79 inches (1.5 to 2.5 centimeters) across, were probably formed by relatively recent meteor impacts. Specifically, the researchers believe that the globules formed from anorthosite, a volcanically-formed rock rich in the mineral feldspar, after a high-energy impact melted the rock and reformed into spheres.

In appearance these Yutu-2 globules appear translucent, unlike the Apollo globules which were either dark or opaque. Since the rover did not do spectroscopy on these objects before moving on, however, their actual make-up is unknown, with the speculations by the researchers above merely that, speculations, though reasonable.

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Scientists: Martian topography in one region suggests the past existence of lakes and river networks, but not a large single ocean

3:53 pm

Based on a just published paper, scientists using orbital topography data and imagery have concluded that more than three billion years ago on Mars ancient rivers in the transition zone between the southern cratered highlands and the northern lowland plains fed into numerous lakes in the lowlands, not a single large ocean as some scientists posit.

From their abstract:

The northern third of Mars contains an extensive topographic basin, but there is conflicting evidence to whether it was once occupied by an ocean-sized body of water billions of years ago. At the margins of this basin are the remnants of deltas, which formed into water, but the size and nature of this water body (or water bodies) is unclear, and detailed investigations of different regions of the basin margins are necessary.

In this study, we use high-resolution image and topographic datasets from satellites orbiting Mars to investigate a series of water-formed landforms in the Memnonia Sulci region, set along the boundary of Mars’s northern basin. These landforms likely formed billions of years ago, providing evidence for ancient rivers and lakes in this region. The geologic evolution of these rivers and lakes was complicated, likely influenced by water-level fluctuations, changes in sediment availability, and impact cratering. Our topographic analysis of these rivers and lakes suggests that they terminated in a series of ancient lake basins at the boundary of Mars’s northern basin, rather than supplying a larger, ocean-sized body of water. [emphasis mine]

Overview map

The Memnonia Sulci region is in the cratered highlands just south of the Medusae Fossae Formation, the largest volcanic ash deposit on Mars. The region of study in it is marked by the blue dot in the overview map to the right.

The study does not preclude the possible existence of a northern ocean on Mars, but it says that at least in this region at the equator, it did not exist. Instead, the various river valleys drained into separate smaller and relatively short-lived lakes.

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Curiosity images the Martian version of a cave formation

10:00 am

An helictite on Mars?
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken today by Curiosity’s Mars Hand Lens Imager (MAHLI), a camera designed to get close high resolution images of very small features on the surface.

The Curiosity image site does not provide a scale, but MAHLI, located at the end of the rover’s robot arm, is capable of resolutions as small as 14 microns per pixel. Since a micron is one thousandth of a millimeter, and the original image was 1584 by 1184 pixels in size, that means the entire image is likely only slightly larger than 18 to 25 millimeters across, or slightly less than an inch.

This feature, which closely resembles a cave helictite, is thus about a quarter inch in size. Helictites, which in caves often resemble wildly growing roots, are nonetheless made of calcite, not organic material. They grow wildly because the water is being pushed out from their center is under pressure, so that as it drips away from the formation it leaves its calcite deposits randomly, causing the formation to grow randomly.

MAHLI also took what looks to be an infrared or heat image of the formation, which appears to show that the tips of the branches are at a different temperature, I think cooler, than the rest of the formation.

While seeping water causes helictites on Earth, what formed this thing on Mars is beyond my guess. It sure looks cool however.

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Dry barren ground in Martian northern lowlands?

3:38 pm

Dry barren ground in the Martian northern lowlands?
Click for full image.

Today’s cool image is intriguing because of what appears to not be there, rather than what is there. The photo to the right, cropped and reduced to post here, was taken on November 3, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

At first glance it appears to show a very dry, barren surface. At its base are many parallel grooves running from the southwest to the northeast. On top of these grooves are several more recent crater impacts, as well as several patches of higher bedrock that appears to have been hard enough to resist whatever erosion process caused the groves.

Yet, based on the overview map below, the location of this photo should not be dry and barren, but instead home to a near-surface ice sheet covering everything.
» Read more

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Curiosity’s coming travels across the rocky Greenheugh Pediment

10:31 am

Curiosity's view west on February 21, 2022 (Sol 3393)
Click for full resolution panorama. Original images can be found here, here, and here.

Overview map
Click for interactive map.

Curiosity, having successfully climbed up and out of Gordon Notch, was able to aim its navigation cameras forward yesterday and get its first views from this position across the very rocky Greenheugh Pediment to its next major goal, Gediz Vallis Ridge. The panorama above, taken by the rover’s right navigation camera, shows this view. The ridge is about 1,500 feet away, at its closest point. The rim of Gale Crater, barely visible in the haze, is about 20-30 miles away.

The overview map to the right indicates the area covered in this panorama by the yellow lines. The red dotted line indicates Curiosity’s planned future route.

Curiosity’s first view of the pediment was made in March 2020, from a point on its northern border, just beyond the top edge of the map. The panorama taken then showed what appeared to be a very treacherous and rough surface, possibly too rough for Curiosity to traverse.

According to the science team’s most recent update from before the holiday weekend, the plan had been to spend February 19-20 studying the ground, then drive a short distance yesterday to get a better view ahead.

This will give us a good vantage point to look into the valley ahead and try to scope out our future route. … We chose to drive about 10m total, in order to get the rover oriented at a good heading and parked in a good spot. We expect a similarly beautiful view from our post-drive imaging.

That view is the panorama above. Though still very rough, the ground ahead appears far more traversable than the surface seen in 2020.

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Deformed Martian craters

2:04 pm

Deformed Martian craters
Click for full image.

Cool image time! The picture to the right, rotated, cropped, and reduced to post here, was taken on September 3, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The focus of the image for the MRO science team were the wedding cake layers inside the largest crater. These layers suggest glacial ice, with the layers suggesting multiple cycles of glacial ebb and flow. Since the crater is at 43 degrees north latitude, and sits in the chaos region dubbed Protonilus Mensae, smack dab in the center of what I call Mars’ glacier country, this conclusion makes perfect sense.

To my eye, however, the most interesting feature of this photo are the many distorted craters. The overview map below shows the picture’s location, as well as several nearby very large impact craters which might have caused many secondary impacts, including the many craters at this location.
» Read more

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Cracking ice on Mars?

12:43 pm

Cracking ice on Mars?
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on December 7, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the MRO science team dubs “erosion of scalloped terrain” in the northern lowland plains of Mars.

The cracks invoke the polygon cracks one sees in mud as it dries. The circular feature suggests a buried crater whose shape is merely suggested because the cracks are conforming to the underground topography.

Are we looking at dried mud? Maybe, but more likely we are seeing a sheet of ice now sublimating away and cracking as it does so. If you look at the full photo you will see the cracked material also appears to drape itself over several nearby low ridges, something that seems more likely from ice than mud.

The overview map below also suggests this is a buried layer of ice.
» Read more

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Curiosity looks out across the mountains

12:20 pm

Curiosity panorama, Sol 3387, February 15, 2022
Click for high resolution. Original images found here and here.

Overview map
Click for interactive map.

Cool image time! The mosaic above, created from two photos taken by Curiosity’s left navigation camera and downloaded from the rover today, looks to the southeast across the small rocky valley the rover has been traversing for the past two months towards Mount Sharp.

The rover had entered this valley through the nearest gap on the left, then traveled uphill from the left to the right until it had passed behind the nearest dark ridge on the right. It then retreated and turned left, starting uphill through Gordon Notch, as shown in the overview map to the right.

On the overview, the white line marks Curiosity’s past travels, with red dotted line indicating its planned future route. The yellow lines indicate the approximate view in the panorama above.

For scale, Navarro Mountain is about 450 feet tall. The actual peak of Mount Sharp is blocked by the white front range to the left. The rover is presently still 12,600 feet below that peak, which sits to the southeast about 35 miles away.

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A floating Martian rock

9:21 am

Mosiac of top of butte
For original images, click here and here.

A floating Martian rock
Click for original photo.

Cool image time! As Curiosity begins the slow and careful journey up through the rocky Gordon Notch onto the even rockier Greenheugh Pedimont layer above, the science team is using its cameras to take pictures of the buttes that form the northern and southern walls of that notch.

The mosiac above and the photo to the right, both cropped and reduced to post here, is one beautiful example. Taken by Curiosity’s high resolution camera on February 11th, both images show the consequences on geology of Mars’ low gravity, one third that of Earth’s. The top image shows the entire top of the butte, with the picture to the right focusing on one boulder that almost seems to be floating in the air. Look close and you can see daylight under the rock’s entire left half.

I think this butte is the north wall of Gordon Notch, but am not sure. Either way, the photos once again demonstrate that it is very dangerous to assign our Earth-based assumptions to Martian geology. There may be similarities, but the differences must not be ignored, or else our conclusions about what we see will be wrong.

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Global image of Mars from UAE’s Al-Amal orbiter

10:23 am

Mars as seen by Al-Amal in January 2022
Click for original image.

Cool image time! The United Arab Emirates (UAE) today released several new images taken by its Al-Amal Mars orbiter, showing the changing atmospheric conditions on Mars between September ’21 and January ’22.

The photo to the right, cropped and annotated by me, is the January image, showing the dust storm conditions that presently exist in the equatorial regions of Mars. The lighter puffy cloud-like features in the center of the image are a 1,500 mile wide dust storm centered on the equator. The white dot indicates the approximate spot where Perseverance sits in Jezero Crater, within that storm.

The previous Al-Amal image from September (available at the link) shows the whole Martian hemisphere with generally clear skies.

Below is a recent photo taken by Perseverance illustrating these dusty conditions.
» Read more

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Parker images the surface of Venus

3:23 pm

Parker image compared to radar maps of Venus
For original images go here and here.

During its flybys of Venus in July 2020 and February 2021 the Parker Solar Probe used its wide field camera to take images of the night side of Venus in red optical and near infrared wavelengths, essentially measuring the heat (in the range of 863 degrees Fahrenheit) being emitted by the planet’s surface.

The resulting images, the first orbital photos of Venus’ surface in the optical, showed continent-sized surface details that matched previously made radar maps, and confirmed as expected that the higher altitudes are cooler than the lower.

The paper outlining these results can be read here.

The two pictures to the right compare previous radar maps (on the right) with the new Parker image (on the left). The central dark and cooler area is a region called Aphrodite Terra, which like Earth’s continents sits higher than the surrounding terrain.

Note that though cooler, the surface at these dark areas is still hellishly hot, more than 800 degrees Fahrenheit. Exploring the surface of Venus is going to be a far far far more challenging task that going to Mars.

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Mars: Glaciers on top of glaciers on top of glaciers

1:16 pm

Overview map
Mars’ glacier country.

glaciers on top of glaciers on top of glaciers
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on December 12, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a small patch of layered glacial features flowing in all directions. The overview map above marks its location by the red dot, at 40 degrees north latitude in the region dubbed Deuteronilus Mensae, on the western end of the 2,000 long strip from 30 to 60 degrees north latitude that I dub Mars’s glacier country because practically every image in this region shows glacial features.

What makes the glacial features in this picture so remarkable is their number, their somewhat chaotic nature, and the evidence of many layers, suggesting a cyclical process of ebb and flow over the eons.

Below I zoom into one section of this photo, showing that section at full resolution.
» Read more

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Ingenuity completes 19th flight

9:19 am

Perserverance and Ingenuity as of February 8, 2022
Click for interactive map.

The Mars helicopter Ingenuity yesterday successfully completed its 19th flight on the Martian surface, traveling for 99 seconds about 200 feet to the northeast, landing close to the landing site of its 8th flight back in June 2021.

The map to the right shows the helicopter’s overall travels in tan, with the 19th flight path in green. The white line marks Perseverance’s travels, with the red dot indicating its present location. The dashed yellow line indicates the rover’s planned route. To achieve that the rover team is retracing its steps along the path it had previously traveled, with Ingenuity flying in front, along that path.

The flight had been delayed more than a month while waiting for a dust storm to settle as well as making sure Perseverance was in a good position to maintain communications throughout the flight. With Perseverance finally on the move to the east and the dust storm subsiding, the Ingenuity flight was finally possible.

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Random Martian ridges on a lava plain

1:02 pm

Random ridges on Martian lava plain
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on December 30, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). This was a terrain sample image, taken not as part of any specific research project but to fill a gap in the camera’s schedule and thus keep its temperature maintained properly. When the MRO team needs to take such pictures, they try to pick locations that might be interesting and previously unphotographed, but often the location is neither.

In this case this terrain sample captured a flat lava plain interspersed with sinuous ridges going in all directions. On top of this is a scattering of smaller impact craters, which obviously occurred after the lava had flowed and solidified.

What caused the ridges?
» Read more

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