Tag: science

Saturn’s polar hexagonal vortex might tower high above clouds

3:35 pm

The uncertainty of science: A long term analysis of data from the probe Cassini suggests that Saturn’s north polar hexagonal vortex might tower many miles high above the planet’s clouds.

A new long-term study has now spotted the first glimpses of a northern polar vortex forming high in the atmosphere as Saturn’s northern hemisphere approached summertime. This warm vortex sits hundreds of kilometres above the clouds, in a layer of atmosphere known as the stratosphere, and reveals an unexpected surprise. “The edges of this newly-found vortex appear to be hexagonal, precisely matching a famous and bizarre hexagonal cloud pattern we see deeper down in Saturn’s atmosphere,” says Leigh Fletcher of the University of Leicester, UK, lead author of the new study.

“While we did expect to see a vortex of some kind at Saturn’s north pole as it grew warmer, its shape is really surprising. Either a hexagon has spawned spontaneously and identically at two different altitudes, one lower in the clouds and one high in the stratosphere, or the hexagon is in fact a towering structure spanning a vertical range of several hundred kilometres.”

There are many uncertainties here. For one thing, we have not yet even observed Saturn from up close through a complete year. We might be seeing random weather events having nothing to do with the gas giants overall planetary weather patterns.

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Sunspot update for August 2018: The slide to minimum

12:28 pm

As it does the first Sunday of each month, yesterday NOAA posted its monthly update of the solar cycle, covering sunspot activity for August 2018. And as I do every month, I am posting it below, annotated to give it some context.

The Sun in August had a slight uptick in sunspot activity, but not a very significant one. As such, the slide to solar minimum continues. Right now the lack of sunspot activity in 2018 is heading to match or even exceed 2007, the year in which the previous solar minimum began.

August 2018 sunspot activity

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

If you look at the original graph at NOAA, you will see that we are getting very close to the right edge of the graph. I expect that sometime in the next few months NOAA will update the graph, a necessary act that will in one sense be a shame, as they have been adding monthly updates to this graph since the beginning of the last solar minimum. This has allowed everyone to see a standard visual, month to month, for comparing solar activity. It has also allowed me to annotate the graph properly to show how the 2007 and 2009 predictions held up against actual activity. Once the graph changes it will be more difficult to do this.

Anyway, it is very clear we are entering solar minimum, and that the solar cycle we are now completing will be both a short and weak cycle. What happens next is really the big question. Will the Sun sunspot activity recover? Or will we enter the first grand minimum since the 1600s? Either way, for solar scientists the coming years are going to be very exciting.

Posted on interstate 10 going from Tucson to Phoenix, on the way to the wooded northern forests of Arizona, where Diane and I will spend a couple of days visiting friends at their upstate cabin/home.

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Some debate at NASA over Opportunity

8:58 am

This story yesterday had the following interesting paragraph:

Members of Opportunity’s engineering team recommended a different plan, the person close to the mission says. Their idea was to actively try to communicate with Opportunity until the end of January 2019 — the end of the seasonal cleaning period. After that, they suggested passive listening until the end of 2019. But these recommendations were ignored by management in order to save money, this person says, meaning the agency could be risking abandoning a still-functioning rover. The Opportunity team reportedly didn’t receive formal notice of the plan until “minutes before JPL published its press release,” according to The Atlantic.

It appears that some on the science team do not feel that the present plan to listen closely for only 45 days, through mid-October, is sufficient, as it will likely require a dust devil to clear Opportunity’s solar panels, and dust devil season will not begin until November.

However, it is very likely wrong to blame the resistance by NASA management to this plan solely to a desire to save money. There are other considerations, such as tying up the Deep Space Network for this one rover when, as I noted yesterday, the October to January time period will be a very very very busy time for that network, with many important new planetary probe events. Seven different spacecraft will either be landing or doing fly-bys on four different solar system targets during that time. Tying the network up to listen for Opportunity will likely not work.

It seems to me that Opportunity should be recovered, if possible, but it also must receive a lower priority during this time period. After New Horizons’ January 1st fly-by of Ultima Thule it might be possible to devote more time then to listening, but I can see the logic, at least in this context, for reducing the listening time from October to January.

Hat tip Kirk Hilliard.

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The upcoming very busy planetary probe season

12:08 pm

The next few months are going to be very busy and exciting for the planetary science community. Seven different probes will be either flying past or landing on four different solar system objects, with interesting events happening every few weeks:

  • September 21: One of Hayabusa-2’s mini-landers, Minerva-II-1, will land on the asteroid Ryugu
  • October 3: Another Hayabusa-2 mini-lander, MASCOT, will land on Ryugu
  • Late October: Hayabusa-2 itself will land and grab a sample of Ryugu
  • November 26: The U.S. lander InSight will land on Mars.
  • December 3: OSIRIS-REx will arrive at the asteroid Bennu.
  • December: Chang’e-4 will land on the Moon’s far side.
  • January 1: New Horizons will fly past the Kuiper Belt object Ultima Thule.

In addition, another Hayabusa-2 mini-lander will also land on Ryugu, sometime after Hayabusa-2’s landing. Moreover, as OSIRIS-REx and New Horizons approach their targets we shall see daily new and increasingly sharper images of both Bennu and Ultima Thule, prior to their arrival.

I expect from September to January there will be many many very cool images coming from space, on almost a daily basis.

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How the Curiosity science team found soft rock for drilling

10:15 am

Link here. They very much wanted drill samples on Vera Rubin Ridge, but had twice found the rock too hard for Curiosity’s drill. So how did they pinpoint the spot, dubbed Stoer, where the drill finally worked?

In the absence of direct data on rock mechanical properties, we came up with three criteria that we could use to try to find a softer rock. (1) Did the bristles of the DRT brush leave scratches on the rocks’ surfaces? While not necessarily a direct indicator of what the rock strength would be when we drilled into it, we could at least say rocks that got scratched with the DRT had a softer surface than those that didn’t. (2) How well exposed are the white calcium sulfate veins? On some rock targets, like Stoer, we clearly see veins. On other targets, like Voyageurs, the veins are recessed into the rock. Recessed veins erode much faster than the surrounding bedrock because the surrounding bedrock is harder. Non-recessed veins tells us the bedrock may be similar in strength to the veins, or, if the veins stick out, the bedrock may be lower in strength. (3) What does the large-scale topography tell us? Broadly, Vera Rubin Ridge is a ridge because it is composed of hard rocks that are more resistant to erosion than their surroundings. We realized we might use this same logic to find softer rocks within the ridge by trying to drill in local topographic lows or at bases of scarps where the bottom of the scarp is eroding more quickly than the hard rocks on top.

The successful drill hole, Stoer, was thus down somewhat from to top of the ridge. As they prepare to move on, it appears they want to try again to drill at the top of the ridge. It also appears that the work described above has maybe found another location there where the rock might be soft enough for the drill.

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As Mars dust storm clears, Opportunity remains silent

10:04 am

The Opportunity science team today provided a new update on the rover, noting that it remains silent even as the Martian dust storm is clearing.

With skies clearing, mission managers are hopeful the rover will attempt to call home, but they are also prepared for an extended period of silence. “If we do not hear back after 45 days, the team will be forced to conclude that the Sun-blocking dust and the Martian cold have conspired to cause some type of fault from which the rover will more than likely not recover,” said Callas. “At that point our active phase of reaching out to Opportunity will be at an end. However, in the unlikely chance that there is a large amount of dust sitting on the solar arrays that is blocking the Sun’s energy, we will continue passive listening efforts for several months.”

The additional several months for passive listening are an allowance for the possibility that a Red Planet dust devil could come along and literally dust off Opportunity’s solar arrays. Such “cleaning events” were first discovered by Mars rover teams in 2004 when, on several occasions, battery power levels aboard both Spirit and Opportunity increased by several percent during a single Martian night, when the logical expectation was that they would continue to decrease. These cleaning dust devils have even been imaged by both rovers on the surface and spacecraft in orbit (see https://mars.nasa.gov/resources/5307/the-serpent-dust-devil-of-mars/).

It appears however that if nothing is heard from Opportunity by sometime in mid-October, they will be very prepared at that time to begin shutting down ground-based operations here on Earth.

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Dates set for first landings on Ryugu

9:10 am

The science team for the Japanese probe Hayabusa-2 have set the dates for the first two landings on the asteroid Ryugu.

On 21 September, it will despatch the first of these piggybacked packages. A 3.3kg container known as Minerva II-1, which is mounted on the spacecraft, will deploy two robots known as Rover 1A and Rover 1B.

The 1kg “rovers” will actually move by hopping under the asteroid’s low gravity. Each one contains a motor-powered internal mass that rotates to generate force, propelling the robot across the surface. The rovers are equipped with wide-angle and stereo cameras to send back pictures from Ryugu.

Then, on 3 October, the mothership will deploy a lander called Mascot, which has been developed by the German Aerospace Center (DLR) in conjunction with the French Space Agency (CNES). Mascot, otherwise known as the Mobile Asteroid Surface Scout, is a 10kg instrument package that will gather a range of scientific data from the surface. It carries a wide-angle camera, a microscope to study the composition of minerals, a radiometer to measure temperature and a magnetometer to measure the magnetic field.

After it reaches the surface, Mascot can move its position only once, by jumping.

An earlier report had said that Hayabusa-2 would itself land late in October, but this report today leaves that landing date unstated.

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The aurora of Saturn

10:11 am

Cool movie time! Using the Hubble space telescope scientists have compiled an animation showing the changes in Saturn’s north pole aurora over time.

In 2017, over a period of seven months, the NASA/ESA Hubble Space Telescope took images of auroras above Saturn’s north pole region using the Space Telescope Imaging Spectrograph. The observations were taken before and after the Saturnian northern summer solstice. These conditions provided the best achievable viewing of the northern auroral region for Hubble.

…The images show a rich variety of emissions with highly variable localized features. The variability of the auroras is influenced by both the solar wind and the rapid rotation of Saturn, which lasts only about 11 hours. On top of this, the northern aurora displays two distinct peaks in brightness — at dawn and just before midnight. The latter peak, unreported before, seems specific to the interaction of the solar wind with the magnetosphere at Saturn’s solstice.

The animation of all the images is embedded below. At the link is a second video showing the aurora in close-up

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Lunar scientist Paul Spudis had passed away

10:03 am

R.I.P.: Paul Spudis, lunar scientist and strong advocate for the human exploration of space, passed away yesterday at the age of 66.

Spudis was one of the best lunar scientists we have had. He also saw past petty budget battles and his personal planetary research to recognize the need for human exploration and settlement on the Moon and elsewhere. This is a premature loss for us all.

Leonard David at Space News has written a fine obituary, which gives only a hint at how important Spudis was to the recent resurgence of the U.S. in the exploration of space.

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Looking for Marsquakes

1:24 pm

After eight and a half years of study of one particular very young fault system on Mars using high resolution images from Mars Reconnaissance Orbiter, scientists have found no evidence that any quakes occurred there in that time.

The team studied images of Mars’s surface over nearly a decade to look for changes that might have been caused by marsquakes. The researchers used images of Mars’s surface from the High Resolution Imaging Science Experiment (HiRISE) and applied Co-registration of Optically Sensed Images and Correlation (COSI-Corr)—software that has been validated to track terrestrial glaciers, landslides, and quakes on Earth, as well as dune movement on Mars itself—to hunt for signs of displacement near fault zones.

The researchers focused on the Cerberus Fossae fault system, the youngest fault system on the Red Planet and thus the most likely to still be active. They used the average coregistration performance of each study image to determine that this method should be able to detect fault slip rates of 0.1–10 millimeters a year.

The team identified only one displacement signal that could have been interpreted as evidence of a marsquake—but dismissed it as the result of a topographic artifact. Their results suggest that no seismic movement occurred in the Cerberus Fossae area over the course of the study, which spanned 8.5 Earth years’ worth of images from the planet.

This suggests, but does not prove, that Mars has very few quakes. We shall know more when InSight lands on Mars on November 26.

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New Horizons snaps first picture of Ultima

8:48 am

It isn’t much more than a tiny moving dot across a sea of stars, but on August 16, 2018 New Horizons was able to capture its first series of images of its January 1st fly-by target, the Kuiper belt object they have nicknamed Ultima Thule.

This first detection is important because the observations New Horizons makes of Ultima over the next four months will help the mission team refine the spacecraft’s course toward a closest approach to Ultima, at 12:33 a.m. EST on Jan. 1, 2019. That Ultima was where mission scientists expected it to be – in precisely the spot they predicted, using data gathered by the Hubble Space Telescope – indicates the team already has a good idea of Ultima’s orbit.

Ultima was 100 million miles away at the time.

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Arecibo gets upgrade, new funding

9:33 am

Back from the dead: Threatened with closure only last year due to lack of funds, then damaged badly from Hurricane Maria, the Arecibo radio telescope in Puerto Rico has not only obtained a new operational funding from a new partner but also a $6 million upgrade.

The money will help design and build a super-sensitive set of antennas to be installed at the focal point of Arecibo’s dish. The 166 antennas, together part of the phased-array feed to be installed in 2022, are expected to significantly increase Arecibo’s capabilities. The phased-array feed will boost the telescope’s sky survey speed, making it five to six times faster than it is now, and it’ll enable the telescope to look at a larger piece of sky at one time.

…This month’s announced upgrade comes after years of uncertainty about Arecibo’s operations. In September 2017 Hurricane Maria caused about $14 million in damage to the telescope and ancillary buildings, some of which is still being repaired today. The facility lost its 430-megahertz line feed, which was used for atmospheric studies. Pieces of the antenna fell and punctured panels in the primary reflector of the main dish, forcing the replacement of 80–90 of the panels. There was also significant flooding under the primary reflector, which damaged some of the lines and heating facilities. In addition, several pieces of electronic equipment, some imagers, and laser rangers were damaged. Three buildings — a maintenance facility, a heater/transmitter building and a family unit — were also partially or completely destroyed due to rock and tree debris.

The hurricane was only the latest challenge for the observatory, after Arecibo had fought off repeated threats of closure over the previous decade due to NSF funding concerns. The latest situation was resolved last February, when a consortium led by the University of Central Florida took over operation and management of the observatory, significantly lessening the burden on NSF.

While Arecibo is no longer the world’s largest single radio dish, having been topped by China’s FAST radio telescope, it appears at least for now better positioned to do research. China does not yet have the radio astronomers experienced enough to operate its telescope, and so FAST at present is significantly under-utilized.

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Hayabusa-1 sample pins down age of asteroid

9:19 am

Using particles gathered by Hayabusa-1 Japanese scientists have determined the age of the asteroid Itokawa.

Japanese scientists, including those from Osaka University, closely examined particles collected from the asteroid Itokawa by the spacecraft Hayabusa, finding that the parent body of Itokawa was formed about 4.6 billion years ago when the solar system was born and that it was destroyed by a collision with another asteroid about 1.5 billion years ago.

These results are only the beginning. As more samples return from more asteroids, scientists will start to add details to the overall history of the formation and evolution of the solar system, adding significant depth to the rough outline they presently have. And these new samples are already on the way, with both Hayabusa-2 and OSIRIS-REx approaching their target asteroids.

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Inexplicable high latitude Martian terrain

2:58 pm

Inexplicable high southern latitude Martian terrain

Strange image time! The image on the right, reduced in resolution to post here, comes from the August 1, 2018 image release from the high resolution camera on Mars Reconnaissance Orbiter (MRO). (If you click on the image you can see the full resolution version.) I have not cropped this image at all, so that you can see all of its swirling terrain.

This image did not come with a caption. The image site merely describes this terrain as having an “interesting morphology.” The location, in the very high southern latitudes (78 degrees south) just outside the southern rim of a very large crater, provides a slight explanation, as the growth and retreat of the Martian carbon dioxide polar caps is known to create very strange landforms. These swirling flows are obviously an example of one such landform.

The crater rim is just off of the top of the image and parallel with it. Therefore, the apparent erosional flows going around the hills and mesas are running parallel to the rim, not down from it. The black specks scattered about are probably points where dust was released as the carbon dioxide turned from ice to gas, a process that at the high latitudes on Mars often causes what planetary scientists call “spiders.”

I will not even try to make a guess at the process that formed what we see here. The image itself was taken on June 16, 2018 as part of a seasonal monitoring effort, which means scientists expect there to be changes occurring here from year to year as the polar cap shrinks and grown. An almost identical image had been taken two years ago, on December 18, 2016, and shows almost no black specks, probably because of the different time in the Martian year. A much closer comparison of both high resolution images would be necessary to tease out any more subtle changes.

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Volcanic rills and lava tubes on Mars

9:34 am

Rills and lava tubes on Pavonis Mons

Cool image time! The image on the right, cropped somewhat to show here, was taken by Mars Odyssey of the southwestern slope of Pavonis Mons, the middle volcano of the line of three giant volcanoes located between the biggest volcano in the solar system, Olympus Mons, and the biggest canyon in the solar system, Marineris Valles. The slope goes down to the south, from the top to the bottom of the image. As noted on the image page,

The channel and nearby oval depressions are both related to the flow of lava. Narrow lava flows can create channels. The cooling of the top of the channel will form a roof over the flow, creating a tube beneath the surface. After the lava stops flowing the tube can empty, leaving a subsurface void. The roof will then collapse into the void forming the oval surface features.

I have added arrows to the image to draw your eye to the features that extend south in line with those oval depressions, eventually widening out to resemble a river delta, with the obvious rill probably indicating the lowest point in that delta.

Though the oval depressions are likely sections of a lava tube that collapsed, the features in line with those depressions suggest that the tube itself might still exist below the surface to the south, feeding into that delta where the rill meanders. It is also possible that my desire to find underground voids here, where glacier ice might possibly exist, might be skewing my conclusion. It could also be that the lava tube ended at these depressions, and what the features indicate is a wide surface flow, later embellished by the smaller flow of the meandering rill.

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China reveals landing site for Chang’e-5 lunar sample return mission

8:56 am

The new colonial movement: In a recent paper Chinese scientists revealed their landing plans for the Chang’e-5 lunar sample return mission, presently scheduled for at 2019 launch.

If all goes according to plan, the robotic Chang’e 5 will land in the Rümker region, which lies within a huge basaltic lunar plain called Oceanus Procellarum (Latin for “Ocean of Storms”).

A recent paper lays out the scientific significance of this site, and what Chang’e 5 may be able to find there. “Recent studies find that the geological features and volcanic history of the moon are far more complex than previously thought, and many of the most interesting areas have been neither explored nor sampled,” states the study, which was led by Yuqi Qian of the School of Earth Sciences at the China University of Geosciences in Wuhan. “One such area is the northern Oceanus Procellarum region, which consists of very young (<2 Ga) [less than 2 billion years old] mare materials and hosts one of the largest volcanic complexes on the moon (Mons Rümker)."
For the study, the research team conducted a detailed geological mapping of the Rümker region using imagery, spectral and altimetry data.

Chang’e-5 should not be confused with Chang’e-4, which is set to launch in the fall to land on the Moon’s far side.

The choice of the volcanic region around the Ocean of Storms is significant, as it indicates that, for at least this mission, China is not focused on the possibly more valuable polar regions where water-ice might be present for future lunar bases. Instead, they are giving a priority to science and geology with this probe. They likely also picked this site because it is near the equator and therefore a bit easier to reach on this first daring sample return mission.

It does appear however that China is taking the long view. The landing choice here suggests to me that they plan many more missions to the Moon, and do not see anyone else in a position to compete with them for territory. The U.S., Russia, and Europe appear to be throwing their eggs into the basket of (F)LOP-G, which will merely orbit the Moon and eat up resources preventing these countries from planning and building any landing missions, for decades. India meanwhile might be a competitor, but at the moment it is far behind.

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Hayabusa-2 science team lay out Ryugu landing schedule

8:41 am

At a press conference yesterday the Hayabusa-2 science team laid out their landing schedule for the spacecraft and its three tiny landers.

The first lander will be one of its two tiny MINERVA-II probes, and will take place in September. This will be followed by the German/French MASCOT probe in early October, followed in turn in late October by Hayabusa-2 itself.

The landings of the first two probes will help them pick Hayabusa-2’s landing site, as well as the site for last MINERVA lander.

Mission planners faced tough choices because the body almost uniformly strewn with boulders. “Ryugu is beautiful, but challenging,” said Aurélie Moussi, a collaborator from the French space agency CNES in Toulouse, at a press conference in Sagamihara, Japan, on 23 August.

…To minimize risks for MASCOT, mission planners mapped the topography of Ryugu and the distribution and size of the boulders on its surface. They ran computer simulations to produce a shortlist of ten options, and then picked one spot on the asteroid’s southern hemisphere. The choice reflected a number of criteria, including average temperatures on the ground and the materials that MASCOT will analyse with its four on-board instruments. “The other sites would have been just as good, or just as difficult,” says MASCOT payload manager Stephan Ulamec of the German Aerospace Center in Cologne. “Wherever we look, there is a lot of big boulders.”

It does appear that the boulder-strewn surface is posing a problem for the engineers.

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Swooping over a lunar cold spot

10:20 am

cold spot crater

Cool image time! The oblique image on the right, reduced and cropped to show here, was taken by Lunar Reconnaissance Orbiter (LRO) of an unnamed crater on the Moon’s far side. (Click on the image to see the full picture.) What makes the crater of particular interest is that it during the long 14-day-long lunar night the area around this young crater quickly cools to a temperature about 10 degrees Fahrenheit colder than the surrounding terrain.

Einthoven cold spot crater, the subject of today’s Featured Image, is 1143 m wide, or about the size of Meteor Crater in Arizona. So far, it has no official name — we call it Einthoven cold spot crater because it is just south of Einthoven crater, which is old, degraded, and, at 69 kilometers in diameter, the largest crater in the neighborhood.

Though craters associated with cold spot anomalies are small, the cold spots themselves are often large. The Einthoven cold spot crater anomaly takes in 2070 square kilometers of terrain and extends up to 50 kilometers from the crater. That’s much too large an area for ejecta from the crater to cover, which eliminates the most obvious cold spot formation hypothesis: that material blasted from the crater during its formation could create the cold spot.

So, how to explain the cold spot anomalies? Some researchers invoke a cascading series of tiny secondary impacts traveling outward from the crater-forming asteroid impact, while others believe that gas produced by the impact flows through the top layer of lunar surface material. Either process might “fluff up” the surface, changing the way heat affects it. Few researchers, however, find these explanations to be 100% convincing.

Though the abstract of one science paper proposes using these cold spots as an easy way to quickly identify young lunar craters, the actual cold area of this particular crater does not correspond perfectly to the crater itself. The temperature map at the link shows that the colder region is not even centered on the crater, and has a very irregular shape. Using these mysteriously cold regions on the Moon to identify young impacts I think will be difficult and will have a very large margin of error.

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Oblique mosiac of bright spot on Ceres

9:40 am

Cerealia Facula on Ceres

Cool image time! With the Dawn spacecraft now swooping with 22 miles of the surface of Ceres every 27 hours, the science team has assembled a spectacular oblique image of Cerealia Facula, one of the dwarf planet’s bright spots thought to be brine deposits that at some point erupted up from below the surface.

The image on the right, reduced in resolution to show here, shows that mosaic. If you click on the image you can see the full resolution version. From the image webpage:

This mosaic of Cerealia Facula combines images obtained from altitudes as low as 22 miles (35 km) above Ceres’ surface. The mosaic is overlain on a topography model based on images obtained during Dawn’s low altitude mapping orbit (240 miles or 385 km altitude). No vertical exaggeration was applied.

There are a lot of intriguing details in the full resolution image. I have highlighted one feature, indicated by the white box and shown in full resolution below.
» Read more

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A strange bulge on Mars

2:45 pm

Pollack Crater

Cool image time! The image on the right is not the cool image, but a context image of 59-mile-wide Pollack Crater, located slightly south of the Martian equator in the planet’s southern cratered highlands. What makes this crater intriguing to planetary scientists, and has prompted them to take many images over the decades, is the bulge in the southwest part of the crater’s floor. You don’t normally see a rise off-center like this inside craters. If there were any peaks, you’d expect them to be in the center, formed during the impact, when the crater floor melts and acts more like water in a pond when you drop a pebble into it, forming ripples with an uplifting drop in the dead center.

It therefore isn’t surprising that planetary scientists have taken a lot of pictures of this bulge, going back to the Mariner 9 orbiter in 1972, which first discovered it. Scientists then dubbed it “White Rock” because in the first black & white images it looked much brighter than the surrounding terrain. Later color images revealed that it is actually somewhat reddish in color, not white. As noted at this Mars Global Surveyor webpage,
» Read more

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Trump EPA proposes new power plant climate rules

10:23 am

The Trump administration has now proposed a revision to the climate rules established by the Obama administration to limit carbon dioxide releases at power plants.

President Donald Trump’s administration released a plan today to regulate carbon dioxide emissions at power plants, undercutting a much broader effort by former President Barack Obama to slash planet-warming gases.

The U.S. Environmental Protection Agency (EPA) proposal would give states wide latitude for determining how to cut greenhouse gases from the power sector, a key contributor in the U.S. to climate change. The proposed rule is far narrower than the Obama plan, which sought to cut emissions across the power sector rather than only at individual plants.

On the campaign trail in 2016, Trump promised to repeal Obama’s rule, called the Clean Power Plan. His administration stopped short of that today and is instead offering a weakened alternative to avoid a potentially damaging defeat in court.

Based on the article and the actual proposal [pdf], I am far from convinced this change reduces regulation that much. It appears to shift the regulation to the states, but whether this simplifies things for power plant operators is very doubtful.

Not surprisingly, the Democrats and various leftist environmental groups oppose the change. Expect lawsuits, since it is absolutely forbidden for any subsequent president to ever change policies set by past Democratic presidents.

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Parker makes first course adjustment

9:29 am

The Parker Solar Probe successfully made its first mid-course correction burn yesterday.

Spacecraft controllers at the mission operation center initiated the two-part TCM-1 [trajectory correction maneuver] beginning at 6:00 a.m. EDT on Aug. 19 with a 44-second burn of the engines. The majority of the engine firing, which lasted just over seven minutes, began at 6:00 a.m. EDT on Aug. 20.

The spacecraft is now traveling at almost forty thousand miles per hour, easily enough to escape the solar system. Its course however is such that it will instead zip past the Sun, at closer distances after each orbit and Venus flyby.

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Can the Earth’s magnetic field shut down and flip in only two centuries?

11:49 pm

A new study of a stalagmite in China suggests that the Earth’s magnetic field can reverse polarity in as little as two centuries, not the thousands of years as previously thought.

He and his ANU colleague Dr Xiang Zhao from the Research School of Earth Sciences contributed to the study of the paleomagnetic record from 107,000 to 91,000 years ago that is based on precise magnetic analysis and radiometric dating of a stalagmite from a cave in southwestern China.

The stalagmite, which is one metre in length and eight centimetres in diameter, has a candle-like shape and ranges in colour from yellow to dark brown. “The record provides important insights into ancient magnetic field behaviour, which has turned out to vary much more rapidly than previously thought,” Professor Roberts said.

In the past century or so the Earth’s magnetic field has weakened by about 10%. Some scientists think it possible this presages a possible magnetic reversal, which is apparently overdue. However, up until now it was assumed from available data that any reversal would take thousands of years for the magnetic field to shut down and then restart with a flipped polarity. This new data says the shutdown can happen within the span of one human life.

It is unclear to me if this increases our risk or decreases it. The magnetic field acts to protect us from the solar wind and other space radiation. When it shuts down there will be consequences, many negative, that we now can’t even predict. If a reversal is beginning now but takes longer to happen we will have at least a thousand years to plan and adapt, but the period of shut down will be far longer, causing more harm. If it happens quickly we will have to scramble to adapt, but the period of harm will be very short, and thus might not have time to cause significant harm.

Either way, this result is decidedly uncertain, based on a single stalagmite. No one should take it too seriously without further confirmation from other evidence.

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New analysis strengthens evidence of water in lunar polar craters

11:37 pm

ice signatures in lunar south pole craters

The uncertainty of science: Scientists using data from India’s Chandrayaan-1lunar orbiter today claimed that they have confirmed water in the Moon’s polar craters.

A team of scientists, led by Shuai Li of the University of Hawaii and Brown University and including Richard Elphic from NASA’s Ames Research Center in California’s Silicon Valley, used data from NASA’s Moon Mineralogy Mapper (M3) instrument to identify three specific signatures that definitively prove there is water ice at the surface of the Moon.

M3, aboard the Chandrayaan-1 spacecraft, launched in 2008 by the Indian Space Research Organization, was uniquely equipped to confirm the presence of solid ice on the Moon. It collected data that not only picked up the reflective properties we’d expect from ice, but was able to directly measure the distinctive way its molecules absorb infrared light, so it can differentiate between liquid water or vapor and solid ice.

Most of the newfound water ice lies in the shadows of craters near the poles, where the warmest temperatures never reach above minus 250 degrees Fahrenheit. Because of the very small tilt of the Moon’s rotation axis, sunlight never reaches these regions.

The image on the right shows the craters surrounding the south pole with water ice signatures, according to this new analysis.

This press release has some puzzling aspects. First, it is almost a decade since this data was gathered. Why is this suddenly reported now, just prior to the launch of Chandrayaan-2? I suspect this release has come out now to garner some PR for that new mission.

Also, there is nothing in this release that explains why these results should be considered more certain than previous results. In fact, previous data from different lunar orbits has been somewhat contradictory, suggesting a lot of uncertainty about the presence of water-ice at the lunar poles that this story does not address or alleviate in any way.

Nonetheless, this new analysis and data adds more weight to the possibility of water near the lunar poles, making that real estate a prime target for future bases. Too bad it is China that is aiming to grab this territory, while NASA wants us to circle the Moon in LOP-G, going nowhere.

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Opportunity’s uncertain future

11:24 pm

Link here. This article from JPL provides a detailed status report on the rover, as well as what will happen if they should regain communications.

After the first time engineers hear from Opportunity, there could be a lag of several weeks before a second time. It’s like a patient coming out of a coma: It takes time to fully recover. It may take several communication sessions before engineers have enough information to take action.

The first thing to do is learn more about the state of the rover. Opportunity’s team will ask for a history of the rover’s battery and solar cells and take its temperature. If the clock lost track of time, it will be reset. The rover would take pictures of itself to see whether dust might be caked on sensitive parts, and test actuators to see if dust slipped inside, affecting its joints.

Once they’ve gathered all this data, the team would take a poll about whether they’re ready to attempt a full recovery.

Even if engineers hear back from Opportunity, there’s a real possibility the rover won’t be the same. The rover’s batteries could have discharged so much power — and stayed inactive so long — that their capacity is reduced. If those batteries can’t hold as much charge, it could affect the rover’s continued operations. It could also mean that energy-draining behavior, like running its heaters during winter, could cause the batteries to brown out.

They remain hopeful, but this article is clearly meant to prepare the public for the possibility that Opportunity’s long journey on Mars might have finally ended.

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Ancient drainage on Mars?

9:49 am

Drainage on Mars?

Cool image time! The image on the right, cropped from the original to post here, was taken by Mars Odyssey on May 13, 2018, and shows what clearly looks like a point where a south-to-north drainage broke through a cliff wall to allow a liquid to flow down into the larger and deeper east-west flowing canyon.

The caption at the website for this image provides only a little analysis.

The right angle intersection of the depressions in this VIS image is one of the graben that form Sacra Fossae. The fossae are located on Sacra Mensa, near the beginning of Kasei Valles. Graben are depressions caused by parallel faults where a block of material drops down along the fault face.

According to this geological interpretation, the depressions initially formed due to this geological process. The image however suggests that a flow of liquid also played a part.

Overview map

This region, indicated by the white cross on the map to the right, is part of the vast drainages that flow down from Mars’ four giant Martian volcanoes. It is located north of Valles Marineris, the largest of all these drainages. This region is also where you find a lot of chaos terrain, which is what the hummocky depression at the bottom of the image resembles. Much of this mysterious geology is thought to have been formed by the liquid water that is theorized to have once flowed down from the volcanoes. Here, it appears that the liquid ponded in the depression at the bottom of the image until it found a path along the north-south graben to break through into the east-west deeper graben.

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China unveils next lunar rover

8:54 am

The new colonial movement: In unveiling its next lunar rover, China today also announced they will hold a contest to name it.

Images displayed at Wednesday’s press conference showed the rover was a rectangular box with two foldable solar panels and six wheels. It is 1.5 meters long, 1 meter wide and 1.1 meters high.

Wu Weiren, the chief designer of China’s lunar probe program, said the Chang’e-4 rover largely kept the shape and conditions of its predecessor, Yutu (Jade Rabbit), China’s first lunar rover for the Chang’e-3 lunar probe in 2013. However, it also has adaptable parts and an adjustable payload configuration to deal with the complex terrain on the far side of the moon, the demand of relay communication, and the actual needs of the scientific objectives, according to space scientists.

Like Yutu, the rover will be equipped with four scientific payloads, including a panoramic camera, infrared imaging spectrometer and radar measurement devices, to obtain images of moon’s surface and detect lunar soil and structure.

The Chang’e-4 lunar probe will land on the Aitken Basin of the lunar south pole region on the far side of the moon, which is a hot spot for scientific and space exploration. Direct communication with the far side of the moon, however, is not possible, which is one of the many challenges for the Chang’e-4 lunar probe mission. China launched a relay satellite, named Queqiao, in May, to set up a communication link between the Earth and Chang’e-4 lunar probe.

I am not sure what they mean by “adaptable parts and an adjustable payload configuration.” That sounds like they upgraded this rover’s design to allow them to use it to build many similar rovers for use elsewhere, not just on the Moon. This sounds good, but the conditions on other planets are so different I’m not sure a direct transfer of the rover will work very well.

Chang’e-4’s launch is presently scheduled for December.

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A gas giant exoplanet so hot it resembles a star

8:45 am

Link here. Key quote:

This sweltering exoplanet, located about 620 light-years away from Earth in the constellation Cygnus, is what astronomers call an “ultrahot Jupiter.” KELT-9b is a giant gas world like Jupiter, the largest planet in our solar system. But it’s way bigger — it has three times the mass and twice the diameter of Jupiter — and it orbits extremely close to its hot parent star, KELT-9.

“Ultrahot Jupiter” is an unofficial term for a hot Jupiter exoplanet with temperatures exceeding 3,100 degrees Fahrenheit (1,700 degrees Celsius). They “are so hot that they have some resemblance to being stars even though they’re planets,” Kevin Heng, an astrophysicist at the University of Bern in Switzerland who participated in the study, told Space.com. KELT-9b can reach temperatures of up to 7,800 degrees F (4,300 degrees C).

This record-breaking heat enabled astronomers to detect iron and titanium in KELT-9b’s atmosphere. While researchers have long suspected that these elements are present on some exoplanets — iron is one of the most abundant elements in the universe — it’s difficult to detect them in cooler environments because the atoms are mostly “trapped in other molecules,” Heng said. However, KELT-9b is so hot that the clouds don’t condense in its atmosphere, allowing individual atoms of iron and other metals to fly solo.

Titanium has been found previously in the atmosphere’s of other exoplanets, but only as part of a molecule.

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Russian astronauts complete 8 hour spacewalk

8:36 am

Link here. Besides doing some basic maintenance work as well as literally tossing four cubesats into independent orbit, the most intriguing work was the installation of a German/Russian antenna designed to track animals.

Icarus is a collaborative environmental experiment between the German Aerospace Center (DLR) and Roscosmos to study the migratory patterns of small animals on Earth. It consists of an antenna and GPS hardware to track the movements of animals that have been tagged with small GPS receivers.

The experiment may provide data about how animals move from one location to another, how animal population density shifts over time, and how diseases spread.

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