Tag: geology

Weird Martian geology: Kaiser Crater

9:58 am

Kaiser Crater bedrock

Cool image time! This week JPL’s image site highlighted a picture taken by Mars Odyssey of the floor and dunes inside Kaiser Crater, located to the west of Helles basin in an area dubbed the Noachis Region.

To my eye, the Mars Odyssey picture was interesting, but not worth a post here on Behind the Black. However, I decided to take a look at what HiRise, the high resolution camera of Mars Reconnaissance Orbiter (MRO), had taken of the same area, just out of curiosity. A search at the master HiRise image site at the same latitude and longitude (-45 latitude, 180 longitude) showed that HiRise had imaged a part of the same area, but at much higher resolution.

When I zoomed in on this hi resolution image I came across some interesting and weird geology, cropped to show here on the right. Now this, I thought, is worth posting. Notice how the dark tracks, caused by dust devils, leave no tracks as they cut across the brighter areas. Obviously, these bright areas have no dust or sand, and are likely solid bedrock of some kind. The depressions might be craters, but they also might not. The raised area around the depressions might have been caused by the impact, or it might have been caused by some internal geological process that caused the depression while also raising the surrounding bulge. Since then the wind has been steadily depositing sand in the depressions, causing it to get trapped there.

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A spectacular collapse feature at Arsia Mons

3:55 pm

Collapse at Arsia Mons

Cool image time! This post could be called an update to my January 8th post, Exploring Arsia Mons. In that post I had compiled together the ten images of Arsia Mons, the southernmost volcano in the line of three giant volcanoes on Mars, that JPL had highlighted over several weeks in early January.

Today, I decided to do some of my own exploration of some of the many images taken of Arsia Mons by all of the Martian orbiters. My goal had been to explore the volcano’s western slopes (an area that had not been featured in the JPL releases) because that is the area where research has found evidence of past glacial activity as well as seasonal water clouds. I haven’t finished that survey, but in the process I came across a spectacular image of a collapse that had been visible in image nine of the January 8th post, but did not stand out there because of the lighting. The image on the right is that better image, cropped to focus in on the collapse itself.

The material at the base of the wall resembles piled up mud, which suggests this collapse is a Martian version of a mud slide. If so, it also suggests the presence of liquid. At the same time, the muddy look might not be from liquid but because of the lighter Martian gravity causing avalanches to be appear different there. The light gravity means material is not as dense, so when it collapses it might break apart more easily into a sandy type flow.

I am only an amateur geologist, so my theories here should not be taken very seriously. Nonetheless, I am sure there are planetary geologists who have looked at this closely because of the information about Martian geology that they can glean from it. I’d be curious to hear their thoughts.

Meanwhile, my exploration of the western slopes of Arsia Mons will continue. In Pioneer the science fiction book I wrote in the early 1980s (now available), I placed my Martian colony in Mangala Valles, a meandering canyon to the west of Olympus Mons that feeds out from the higher southern regions into the lower northern flat plains where even then some scientists thought an ocean might have once existed. My thinking then was that this might be a good location to find underground water. It now appears, with our greater knowledge, that the slopes of the volcanoes themselves might be more promising, and I am curious to find the most likely places in this region where a future colony might end up.

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Exploring Arsia Mons

2:01 pm

Master index

In November over a period of two weeks the Mars Odyssey team posted ten images of Pavonis Mons, the smallest of the aligned three giant volcanoes just to the east of Olympus Mons, the largest known volcano in the solar system. I then made all of those images available in a single link, with some analysis.

They have now done the same thing for the southernmost (and possibly the most interesting) of those three aligned volcanoes, Arsia Mons. From the first image below:

Arsia Mons is the southernmost of the Tharsis volcanoes. It is 270 miles (450km) in diameter, almost 12 miles (20km) high, and the summit caldera is 72 miles (120km) wide. For comparison, the largest volcano on Earth is Mauna Loa. From its base on the sea floor, Mauna Loa measures only 6.3 miles high and 75 miles in diameter. A large volcanic crater known as a caldera is located at the summit of all of the Tharsis volcanoes. These calderas are produced by massive volcanic explosions and collapse. The Arsia Mons summit caldera is larger than many volcanoes on Earth.

In other words, you could fit almost all of Mauna Loa entirely within the caldera of Arsia Mons.

The image on the right above is the master index, annotated by me to show the area covered by each image. The images can accessed individually below.
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Faults on Mars

9:20 am

Faults on Mars

Cool image time! The Mars Reconnaissance Orbiter (MRO) image on the right, reduced in resolution to post here, captures a distinctive fault line that cuts across some layered deposits. As noted by the MRO science team,

Some of the faults produced a clean break along the layers, displacing and offsetting individual beds (yellow arrow).

Interestingly, the layers continue across the fault and appear stretched out (green arrow). These observations suggest that some of the faulting occurred while the layered deposits were still soft and could undergo deformation, whereas other faults formed later when the layers must have been solidified and produced a clean break.

Meridiani Planum

These layers are located in Meridiani Planum, a relatively flat area on the Martian equator. Opportunity landed on this plain to the southwest of this region, as shown on the geology map to the left. The white cross in the southwest corner indicates Opportunity’s landing site, with Endeavour Crater just to the southeast. The white box in the northwest shows where the faulted layered deposits are located. Based on the scale of the map, this places Opportunity approximately 400 miles away.

What exactly caused these distinct faults remains unknown. The likely cause would be a earthquake, but since Mars does not have plate tectonics like the Earth, earthquakes would have to be caused by other geological processes not yet studied.

To my eye, they look like cracks in a mirror, though this provides no real explanation other than it illustrates how cool the image is.

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Squiggles on Mars

9:17 am

Squiggles on Mars

Cool image time! The image on the right, reduced and cropped to post here, shows a sand dune slope with numerous squiggly troughs that end either in a small pit or slowly fade away. At first glance one things the troughs were caused by a boulder rolling downhill, but there are no boulders at the base of the slope, and a rolling boulder wouldn’t create so many similar squiggles like this.

The explanation is that the boulders are made of carbon dioxide ice.

Just like on Earth, high-latitude regions on Mars are covered with frost in the winter. However, the winter frost on Mars is made of carbon dioxide ice (dry ice) instead of water ice. We believe linear gullies are the result of this dry ice breaking apart into blocks, which then slide or roll down warmer sandy slopes, sublimating and carving as they go.

The linear gullies exhibit exceptional sinuosity (the squiggle pattern) and we believe this to be the result of repeated movement of dry ice blocks in the same path, possibly in combination with different hardness or flow resistance of the sand within the dune slopes.

For a really entertaining explanation of this process, take a look at the embedded video below the fold.
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The mysterious dark splotches of Mars

11:58 am

The dark splotches of Mars

Cool image time! The image on the right, cropped and reduced in resolution to post here, shows one particular dark splotch in a region with several similar dark areas.

Geologists aren’t quite sure what to make of the dark splotch in the middle of this image, one of several similar dark splotches that extend east and west for over 100 kilometers. From measurements made in infrared, this and other dark splotches have what we call “high thermal inertia,” meaning that it heats up and cools down slowly. Scientists use thermal inertia to assess how rocky, sandy, or dusty a place is. A higher thermal inertia than the surrounding area means it’s less dusty.

The image below the fold shows at full resolution the area indicated by the white box. It provides me no clue as to the cause for the darker color. I think we can speculate all we want, but the truth is that we simply don’t have enough information. We need a closer look, including boots on the ground, to figure this out.
» Read more

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Database of presumed human-caused earthquakes created

9:52 am

The uncertainty of science: Geologists have assembled a database of more than 700 earthquakes they think might have been caused by human activity.

The Human-Induced Earthquake Database, or HiQuake, contains 728 examples of earthquakes (or sequences of earthquakes) that may have been set off by humans over the past 149 years. Most of them were small, between magnitudes 3 and 4. But the list also includes several large, destructive earthquakes, such as the magnitude-7.8 quake in Nepal in April 2015, which one paper linked to groundwater pumping.

Miles Wilson, a hydrogeologist at Durham University, UK, and his colleagues describe the database in a paper set to be published on October 4 in Seismological Research Letters2. The scientists say that HiQuake is the biggest, most up-to-date public listing of human-caused quakes ever made. By bringing the data together in this way, they hope to highlight how diverse induced quakes can be — and help society to understand and manage the future risk.

Many of these quakes were likely caused by human activity. Many however might not have been. The jury is still out, as the article reluctantly admits near the end.

All possible instances of induced quakes were included “without regard to plausibility”, writes the team, because of the difficulty involved in deciding what constitutes absolute proof that an earthquake was caused by human activity. But that could mislead people about the real hazard from induced quakes, says Raphaël Grandin, a geophysicist at the Institute of Earth Physics in Paris. “When you put a dot in the database, and a scientific reference behind it, then you may lead the non-expert to think that the earthquake was caused by humans,” he says. Such a listing might hide scientific uncertainty, as with the Chinese quake: despite the paper linking it to reservoir filling, many seismologists do not believe it was triggered by human activity.

In other words, they included every quake that had the slightest suggestion it was connected to human activity, without noting the uncertainties. This makes this database to me somewhat suspect. Rather than identify the known reliable links between human activity and quakes in order to learn what causes them, this database seems more designed as a political propaganda tool aimed at limiting future human activity. It certainly doesn’t clarify our knowledge on this subject, but instead muddies the water significantly.

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Astronomers discover complex molecules in protostar accretion disk

10:18 am

Astronomers have discovered several complex molecules in the accretion disk surrounding a very young baby star about 1300 light years away in the constellation Orion.

The research team’s ALMA observations have clearly detected an atmosphere of complex organic molecules above and below the disk. These include methanol (CH3OH), deuterated methanol (CH2DOH), methanethiol (CH3SH), and formamide (NH2CHO). These molecules have been proposed to be the precursors for producing biomolecules such as amino acids and sugars. “They are likely formed on icy grains in the disk and then released into the gas phase because of heating from stellar radiation or some other means, such as shocks,” says co-author Zhi-Yun Li of the University of Virginia.

What is even most interesting about this discovery is that these complex molecules are not scattered throughout the disk, but are concentrated in regions above and below its central plane, what the astronomers are labeling “an atmosphere.” This suggests that differentiation — the same process that separates the heavier molecules from lighter ones both in centrifuges and in the cores of planets — occurs quickly in accretion disks as well.

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A river canyon on Mars

11:02 am

A river on Mars

Cool image time! The image on the right, reduced in resolution significantly to show here, was taken by the Themis camera on Mars Odyssey, and shows an unnamed canyon on Mars. Be sure to click on the image to see the full resolution version.

This canyon of course no longer has anything flowing in it. Moreover, it is not clear whether this was formed by water or lava. Unfortunately, the image is part of a series of “Art images” from Mars Odyssey, where they pick an image and suggest it looks like something else. In this case, they are claiming this looks like a “snake, slithering down the image.” Cute, but not very helpful. And unfortunately, they don’t add any further details at all about the image or its location. The context image suggests this canyon is next to a volcano.

After doing further research at the Themis image site, I was able to locate this image on Mars (using latitude 32.0515 and longitude 152.236 given at the link) and look at the images surrounding this one. Further research identified the volcano as Hecates Tholus in the Elyesium Plantia region to the west of Mars’s giant volcanoes.

Looking at all the nearby Mars Odyssey images, it appears that there are a lot of flows like this in this area, and all of them appear to be lava flows, with this one being the largest. A close look at the area just to the south of where the deep canyon opens out shows that the small surface flow draining into the canyon also appears to sit on much larger surface flows (at least two) that left the surface higher than the surrounding terrain.

Elyesium Plantia itself is a plateau, somewhat close to the border between Mars’s southern highlands and the northern plains where some scientists think an ocean might have once existed. Thus, it makes sense that the canyon drains north, as it is following the dip down to those northern low plains.

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Largest quake in Yellowstone since 2014

10:03 am

The USGS today recorded a magnitude 4.5 earthquake at Yellowstone today, the largest since a magnitude 4.8 occurred in March 2014, and part of a continuing swarming of small quakes that began on June 12.

This sequence has included approximately thirty earthquakes of magnitude 2 and larger and four earthquakes of magnitude 3 and larger, including today’s magnitude 4.5 event.

It is hard to say whether this swarm of small quakes portend a really big volcanic event, or will simply die off in the coming days. Recent data at Yellowstone has suggested the former is possible, though not imminent.

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The rings of Saturn

9:38 am

The rings of Saturn up close

Cool image time! The image to the right, cropped to post here, is part of one of the closest and highest resolution images that Cassini has yet taken of Saturn’s rings. The image was taken in January during one of the spacecraft’s ring grazing orbits, and has a resolution of 2,300 feet per pixel. And yet, as noted by the Cassini science team, “Even at this level of detail, it is still not fine enough to resolve the individual particles that make up the ring.”

In prepping the image, all I did was crop it to show the closest rings. I purposely did not reduce its resolution, so that you can see that no individual particles are visible. The rings of Saturn are truly made up of billions of small objects, behaving in many ways like liquid floating in the gravity well of Saturn. If you don’t believe me, download the full image and zoom in on it as much as you like. All you will see are pixels.

The fundamental science question therefore is not how Saturn’s rings behave (though this is certainly important and quite fascinating) but why did those rings end up the way they are. No other planet has rings anything like Saturn’s in their density and make-up. Why? Are Saturn’s rings a normal process that only occurs for short times around planets, which is why only Saturn has these types of rings at present? Or is it a rare event, so rare that we happen to be very lucky to see such a thing at all?

Even more important, Saturn’s rings and their behavior are likely linked closely to the same phenomenon that describe the formation of planets around a star. The more we can learn about why these rings exist, the more we will learn about why planets exist, both here circling the Sun as well as around stars everywhere else.

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The layered mesas of Mars

12:06 pm

The mesas of Uzboi Valles

Cool image time! The image above, reduced and cropped to post here, shows the layered deposits and complex erosion that has taken place in this area of Mars dubbed Uzboi Vallis. As noted at the Mars Reconnaissance Orbiter post,

Layered deposits in Uzboi Vallis sometimes occur in alcoves along the valley and/or below where tributaries enter it. These deposits may record deposition into a large lake that once filled Uzboi Vallis when it was temporarily dammed at its northern end by the rim of Holden Crater and before it was overtopped and breached allowing water to drain back out of the valley.

It is important when looking at these erosion patterns, including the strangely shaped rippled sand dunes scattered through the larger image, that wind possibly plays an even more important part in causing erosion on Mars than liquid water might have in the far past.

Either way, the terrain here has the same stark and fascinating beauty as that seen in the American southwest. If we can ever make it possible to live on Mars, this will definitely be a place to visit when on vacation.

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Scientists estimate age of bright spots in Occator Crater on Ceres

8:22 am

Using crater counts and a careful analysis of features in Occator Crater on Ceres, scientists have estimated that the last major eruption occurred about 4 million years ago.

Nathues and his team interpret the central pit with its rocky, jagged ridge as a remnant of a former central mountain. It formed as a result of the impact that created Occator Crater some 34 million years ago and collapsed later. The dome of bright material is much younger: only approximately four million years. The key to determining these ages was the accurate counting and measuring of smaller craters torn by later impacts. This method’s basic assumption is that surfaces showing many craters are older than those that are less strongly “perforated”. Since even very small craters are visible in highly resolved images, the new study contains the most accurate dating so far.

“The age and appearance of the material surrounding the bright dome indicate that Cerealia Facula was formed by a recurring, eruptive process, which also hurled material into more outward regions of the central pit”, says Nathues. “A single eruptive event is rather unlikely,” he adds. A look into the Jupiter system supports this theory. The moons Callisto and Ganymede show similar domes. Researchers interpret them as volcanic deposits and thus as signs of cryovolcanism.

The volcano itself has slumped away, leaving behind the bright depression. Whether any cryovolcanism is still occurring underground remains unknown.

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The vanishing volcanoes of Ceres

10:02 am

New research based on Dawn data suggests that volcanoes on Ceres flatten and disappear over time.

NASA’s Dawn spacecraft discovered Ceres’s 4-kilometer (2.5-mile) tall Ahuna Mons cryovolcano in 2015. Other icy worlds in our solar system, like Pluto, Europa, Triton, Charon and Titan, may also have cryovolcanoes, but Ahuna Mons is conspicuously alone on Ceres. The dwarf planet, with an orbit between Mars and Jupiter, also lies far closer to the sun than other planetary bodies where cryovolcanoes have been found.

Now, scientists show there may have been cryovolcanoes other than Ahuna Mons on Ceres millions or billions of years ago, but these cryovolcanoes may have flattened out over time and become indistinguishable from the planet’s surface. They report their findings in a new paper accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union. “We think we have a very good case that there have been lots of cryovolcanoes on Ceres but they have deformed,” said Michael Sori of the Lunar and Planetary Laboratory at the University of Arizona in Tucson, and lead author of the new paper.

The cause of the flattening?

Viscous relaxation is the idea that just about any solid will flow, given enough time. For example, a cold block of honey appears to be solid. But if given enough time, the block will flatten out until there is no sign left of the original block structure. On Earth, viscous relaxation is what makes glaciers flow, Sori explained. The process doesn’t affect volcanoes on Earth because they are made of rock, but Ceres’s volcanoes contain ice – making viscous relaxation possible.

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USGS responds to Congressional inquiry about data tampering with blank documents

4:01 pm

Why we got Trump: In response to a demand for documents from a Congressional investigation into data manipulation that the US Geological Survey allowed two chemists to do for nearly two decades, the USGS turned over documents with almost all the pages blank.

“Are we supposed to play tic-tac-toe on this?” Gohmert asked Tuesday, while waving one of the documents during a hearing of the House Natural Resources Subcommittee on Oversight and Investigations on the data manipulation. The USGS lab where two chemists skewed data for nearly two decades was finally closed in March 2016.

Gohmert’s subcommittee had requested the documents in September. The blanks received Tuesday represented only a small portion of the total sought by the panel. “We’re still waiting for documents we requested three months ago,” Gohmert said. “Some of the documents we did receive were redacted, they were duplicates or were even blank pages.”

Meanwhile, the USGS refuses to name the two chemists or describe how they were punished. For all we know, they still work there. And it is important to note, that the data manipulation took place in connection with “various energy-related topics, including coal reserves and uranium deposits.” Want to bet the manipulation was done to discourage development?

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Curiosity finds a meteorite

6:37 pm

The Curiosity science team have identified and now analyzed a nickel-iron meteorite that Curiosity spotted on October 27.

Scientists of the Mars Science Laboratory (MSL) project, which operates the rover, first noticed the odd-looking rock in images taken by Curiosity’s Mast Camera (Mastcam) at at a site the rover reached by an Oct. 27 drive. “The dark, smooth and lustrous aspect of this target, and its sort of spherical shape attracted the attention of some MSL scientists when we received the Mastcam images at the new location,” said ChemCam team member Pierre-Yves Meslin, at the Research Institute in Astrophysics and Planetology (IRAP), of France’s National Center for Scientific Research (CNRS) and the University of Toulouse, France.

ChemCam found iron, nickel and phosphorus, plus lesser ingredients, in concentrations still being determined through analysis of the spectrum of light produced from dozens of laser pulses at nine spots on the object. The enrichment in both nickel and phosphorus at some of the same points suggests the presence of an iron-nickel-phosphide mineral that is rare except in iron-nickel meteorites, Meslin said.

The find is not unprecedented but it is interesting nonetheless.

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Comet 67P/C-G slowly breaking apart

5:56 pm

A comparison of Rosetta images before and after Comet 67P/C-G’s close approach to the sun last year found new fractures and an enlargement of older fractures.

The fractures appear to be developing as forces subtly bend the comet to and fro, Stubbe Hviid, a planetary scientist at the German Aerospace Center Institute of Planetary Research in Berlin, reported October 17 in a press conference at a meeting of the American Astronomical Society’s Division for Planetary Sciences. Hviid and colleagues combined maps from Rosetta with computer simulations of all the forces at work within the comet to determine how the cracks develop. They found that the two bulbous ends rock in opposite directions as the comet spins, flexing the neck and creating severe stress. Because the comet isn’t held together strongly — it’s a conglomeration of dust and ice not much stickier than snow, Hviid said — the neck is starting to break. After a few hundred more years, he said, the comet could fold itself in half as the two lobes snap apart and smoosh together.

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Active volcano on Venus?

5:18 pm

The uncertainty of science: A new analysis of past data from a variety of Venus orbiters suggests that at least one volcano is active there.

The review of old data from the Magellan and Venus Express orbiters suggests that some lava flows on the volcano’s slopes are fresh, though how fresh remains unknown. However, computer models and the detection of excess heat by Venus Express on the mountain’s eastern slopes adds weight to the theory that the volcano is spewing out lava.

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An ancient volcanic mountain chain on Mars

10:10 am

Using data from Mars Odyssey scientists have determined that a mountain chain on Mars was likely created as a chain of volcanoes.

They analyzed the geography and mineralogy of this area they termed Greater Thaumasia, which is about the size of North America. They also studied the chemistry of this area based on Gamma Ray Spectrometer data collected by the Mars Odyssey Orbiter, which was launched in 2001. What they found was the mountain ridge that outlines Greater Thaumasia was most likely created by a chain of volcanoes.

Their research also looked to see if water influenced the mountains’ formation and found no evidence for it. The mountain chain itself is south of the giant Valles Marineris canyons and southeast of the Tharsis region where Mars’ biggest four volcanoes are located.

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Mars’ weird windblown surface

1:39 pm

Wind scoured Martian surface

Cool image time! The image on the right, taken by Mars Reconnaissance Orbiter (MRO) and cropped from a wider view of a small crater and a small volcano caldera, certainly appears blurred and out of focus. Is MRO malfunctioning?

Nope. The blurring is actually an optical illusion caused almost entirely by our own assumptions of what a planet surface should look like combined with the alien processes occurring on Mars that have no equivalent here on Earth.

Below the fold is a wider view from the full image, showing the area of the cropped image to the right as well as the entire crater. Below that is another full resolution inset, this time showing the features on the crater rim that are sharp and stand out clearly. The blurriness of the rest of the image is not because the image is out-of-focus, but because a steady northwest-to- southeast wind has distorted everything in the same direction.
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An avalanche pile on Mars

11:41 pm

Avalanche pile on Mars

Cool image time! The Mars Odyssey science team has released this very interesting image, cropped on the right, of an avalanche debris pile formed when the large section of cliff on the left broke off and collapsed into the valley below. The valley is called Tiu Valles and is located close to Mars’ equator.

The wide spread of the debris is an indication of several things. For one, it illustrates the light Martian gravity, which allowed the debris to flow much farther than it would have on Earth.

For another, the spread of the debris pile suggests to me that the material that fell was very crumbly. It might have been able to hold together as a cliff for a long time, but when it collapsed the material broke apart almost like sand. Think of a sand castle you might have built as a kid on the beach. With a little moisture you can pack the sand to form solid shapes, but if your shape breaks apart the sand falls not as large blocks but as crumbly soft and loose sand. That is what appears to have happened here.

There is also the suggestion to me that water might have been involved somehow in this collapse. I am not a geologist so this speculation on my part is very unreliable. However, the shape of the debris pile suggests a liquid flow. The flow itself wasn’t liquid, but liquid might have somehow been involved in causing this geological event. We would need a geologist however to clarify these guesses on my part.

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Statistical analysis suggests Moon can cause quakes

9:37 am

The uncertainty of science: A careful statistical analysis of when major earthquakes occur has suggested they are more likely to be more powerful if they occur around the full and new moons when tidal forces are at their peak.

Satoshi Ide, a seismologist at the University of Tokyo, and his colleagues investigated three separate earthquake records covering Japan, California and the entire globe. For the 15 days leading up to each quake, the scientists assigned a number representing the relative tidal stress on that day, with 15 representing the highest. They found that large quakes such as those that hit Chile and Tohoku-Oki occurred near the time of maximum tidal strain — or during new and full moons when the Sun, Moon and Earth align.

For more than 10,000 earthquakes of around magnitude 5.5, the researchers found, an earthquake that began during a time of high tidal stress was more likely to grow to magnitude 8 or above.

As these results are based entirely on statistical evidence, not on any direct link between tidal forces and actual quakes, they are quite uncertain and unproven.

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The alien buttes of Mars

11:30 am

Weird Mars

The image above is cropped from a panorama created by reader Phil Veerkamp from images taken by Curiosity’s mast camera on August 25, 2016 of the terrain that partly surrounds the rover since it passed the Balanced Rock and traveled beyond Murray Buttes

The full image is too large to post here. However, if you click on the first link above you can either download it and peruse it at your leisure, or view it with your browser. You will definitely want to do so, as it is high resolution and shows a lot of strange and alien geology, including multiple slabs seemingly hanging in space because of the low gravity. (Hint: Be sure to pan all the way to the right!) On the image’s left Mount Sharp can be seen raising in the background. Below the fold I have annotated the most recent Mars Reconnaissance Orbiter image of Curiosity’s location to indicate what I think is the area included in this panorama. This MRO image also shows that once Curiosity gets through the narrow gap to the south, the path heading south up the mountain’s slopes will, for awhile at least, be relatively open with few large obstacles. The view will also change, as the rover will be out of the region of buttes.
» Read more

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Fossilized rivers on Mars

8:17 am

The uncertainty of science: Using high resolution images from Mars Reconnaissance Orbiter scientists have identified more than 10,000 miles of fossilized rivers on Mars.

The new study examined images covering an area roughly the size of Brazil at a much higher resolution than was previously possible – six metres per pixel compared to 100 metres per pixel. While a few valleys were identified, the team revealed the existence of many systems of fossilised riverbeds which are visible as inverted channels spread across the Arabia Terra plain.

The inverted channels are similar to those found elsewhere on Mars and Earth. They are made of sand and gravel deposited by a river and when the river becomes dry, the channels are left upstanding as the surrounding material erodes. On Earth, inverted channels often occur in dry, desert environments like Oman, Egypt, or Utah, where erosion rates are low – in most other environments, the channels are worn away before they can become inverted. “The networks of inverted channels in Arabia Terra are about 30m high and up to 1–2km wide, so we think they are probably the remains of giant rivers that flowed billions of years ago. Arabia Terra was essentially one massive flood plain bordering the highlands and lowlands of Mars. We think the rivers were active 3.9–3.7 billion years ago, but gradually dried up before being rapidly buried and protected for billions of years, potentially preserving any ancient biological material that might have been present,” added Joel Davis.

These geological forms are different than most of the more well-known Martian channels in that they are not channels but meandering riverlike ridges, higher than the surrounding terrain. Arabia Terra, where they are located, is a transition region in the northern mid-latitudes between Mars’s southern highlands and its northern flat plains, where some believe an ocean once existed.

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Curiosity prepares to move on

8:44 am

Route through Murray Buttes

After several days of drilling, the Curiosity science team is preparing to move forward. As one member of the team notes,

After a short drive we’ll acquire images for context and targeting. Overnight, Curiosity will complete a SAM electrical baseline test to monitor instrument health. Based on some of the recent Mastcam images that we’ve acquired…, the view ahead should be quite scenic as we drive through the Murray Buttes!

The image above is a close-up of those Buttes, showing Balanced Rock on the left, taken from one of three raw left navigation images. The image below is a panorama I have created from those navigation images, with an inset box to show the location of the above picture.
» Read more

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Craters on Ceres

4:10 pm

craters on Ceres
Cool image time! The image above, cropped and reduced in resolution to show here, was taken on May 30, 2016 by Dawn from 240 miles away. It looks northward at the dwarf planet’s horizon, and has a resolution of about 120 feet per pixel.

My only comment is to note how soft the terrain looks. I realize this is not really an accurate description, but data has shown that Ceres has a somewhat low density and is somewhat malleable. It sure looks that way here.

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Rivers of liquid carved deep gorges on Titan

9:07 am

Cassini radar data of Via Flumina

Cool image time! New data from Cassini has now both confirmed that there is liquid inside some of the river-like formations on Titan, and that this liquid has carved these formations into very deep gorges.

The Cassini observations reveal that the channels — in particular, a network of them named Vid Flumina — are narrow canyons, generally less than half a mile (a bit less than a kilometer) wide, with slopes steeper than 40 degrees. The canyons also are quite deep — those measured are 790 to 1,870 feet (240 to 570 meters) from top to bottom.

The branching channels appear dark in radar images, much like Titan’s methane-rich seas. This suggested to scientists that the channels might also be filled with liquid, but a direct detection had not been made until now. Previously it wasn’t clear if the dark material was liquid or merely saturated sediment — which at Titan’s frigid temperatures would be made of ice, not rock.

The diagram on the above right is from the paper itself, and shows some of the radar data obtained by Cassini. It also illustrates the deep and narrow nature of Via Flumina. This is almost the equivalent of what we call slot canyons on Earth, formed by periodic flash floods that cut their way down as the surface is slowly uplifted by other processes.

The new radar data showed that the surface at the base of the gorge was smooth and flat, just as you’d find if that base was filled with liquid.The altimeter data showed that gorge’s elevation matched that of Titan’s lakes at its insurgence, but as you traveled upstream the elevation rose, just as it does on any river on Earth. Moreover, this data was reasonably trustworthy as they had already used Cassini to successfully do exactly the same thing — identify a known river — when it flew past Earth on its way to Saturn.

Be prepared for one piece of misinformation when the press reports on this story, almost certainly caused by the American Geological Union’s press release about this paper. That press release incorrectly claims that the paper confirmed that these are methane rivers. It does no such thing. It only shows that the gorges have a liquid in them, and that the liquid almost certainly formed the gorges. Though methane is a very likely candidate for this liquid based on what we know of Titan, the actual make-up of the river remains uncertain.

I therefore predict our incompetent modern mainstream press will only read this press release and not the paper itself, and thus they will tout these incorrectly as methane rivers.

Below is a cropped Cassini radar image of Via Flumina, showing its river-like appearance. Scientists always suspected these were formed by flowing liquid. Now they have strong evidence from within the gorge to justify that suspicion.

Via Flumina on Titan

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Wind erosion on Mars

9:17 am

Wind erosion on Mars

Cool image time! The image on the right, cropped to show here, was taken by Mars Odyssey. While the features shown appear at first glance to have been formed by water, they have instead in etched by wind.

The narrow ridge/valley system seen in this image are a feature called yardangs. Yardangs form when unidirectional winds blow across poorly cemented materials. Multiple yardang directions can indicate changes in regional wind regimes.

The release does not say what direction the wind was blowing, but if I had to guess, I’d say from south to north.

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The interior of Ceres

11:06 am

Using data from Dawn, scientists have created their first rough map of the internal structure of Ceres.

The data indicate that Ceres is “differentiated,” which means that it has compositionally distinct layers at different depths, with the densest layer at the core. Scientists also have found that, as they suspected, Ceres is much less dense than Earth, the moon, giant asteroid Vesta (Dawn’s previous target) and other rocky bodies in our solar system. Additionally, Ceres has long been suspected to contain low-density materials such as water ice, which the study shows separated from the rocky material and rose to the outer layer along with other light materials. “We have found that the divisions between different layers are less pronounced inside Ceres than the moon and other planets in our solar system,” Park said. “Earth, with its metallic crust, semi-fluid mantle and outer crust, has a more clearly defined structure than Ceres,” Park said.

Scientists also found that high-elevation areas on Ceres displace mass in the interior. This is analogous to how a boat floats on water: the amount of displaced water depends on the mass of the boat. Similarly, scientists conclude that Ceres’ weak mantle can be pushed aside by the mass of mountains and other high topography in the outermost layer as though the high-elevation areas “float” on the material below. This phenomenon has been observed on other planets, including Earth, but this study is the first to confirm it at Ceres.

In other words, Ceres behaves more like a semi-hardened blob of jello than a rock.

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