Tag: science

More successful image downloads for Curiosity

11:24 am

It increasingly looks like the computer download issues on the Mars rover Curiosity are being solved. For the first time in more than five weeks engineers were able to download numerous images from both of the rovers hazard avoidance cameras as well as both of its navigation cameras. More importantly, for the first time in five weeks they were able to do this two days in a row.

The Curiosity science team has as yet released no press update, but it appears that they are carefully testing the computer to make sure it is functioning properly. This computer was the rover’s original primary computer, but when it had problems several months after landing they had switched to the back-up computer. When that back-up computer had problems sending data back to Earth in September they decided to switch back to the original computer, which had been thought fixed.

Because of the original issues with the primary computer I suspect they are simply proceeding very slowly, so as not to have something fail in a manner that will not be recoverable. First they used it two weeks ago to upload a handful of small images from the hazard avoidance and navigation cameras. Then, after a week of analysis they uploaded a few more images from these cameras.

Then, after another week of analysis, they uploaded a full complement of images from all four cameras, and they did it two days in a row, suggesting that they are increasingly confident that the computer is operating correctly.

I expect a press release updating us on the specifics any time now.

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Hayabusa-2 completes third Ryugu touchdown rehearsal

9:34 am

Ryugu up close

Hayabusa-2 today completed its third Ryugu touchdown rehearsal.

According to their operation schedule, they were planning to descent to about 20 meters of the surface, about 65 feet. The image on the right is the closest image taken during the rehearsal. You can see the shadow of Hayabusa-2 in the middle of the frame.

They have not released any information about the rehearsal results. The key here is how accurately they were able to get Hayabusa-2 to approach the asteroid’s largest flat spot, a tiny 20 meter wide spot less than half the size of their original planned landing diameter. From the image, it is unclear how successful they were.

They will now spend the next two months analyzing the data from their landing rehearsals in preparation for a landing attempt in January. During this time observations will be reduced because the Sun will be between the Earth and the asteroid.

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Parker looks back at Earth

8:51 am

Earth and Moon, taken by the Parker Solar Probe

The Parker Solar Probe, flying inward towards its first close fly-by of the Sun, has looked back at the Earth and snapped its picture.

The image was captured by the WISPR (Wide-field Imager for Solar Probe) instrument, which is the only imaging instrument on board Parker Solar Probe. During science phases, WISPR sees structures within the Sun’s atmosphere, the corona, before they pass over the spacecraft.

…Zooming in on Earth reveals a slight bulge on the right side: that is the Moon, just peeking out from behind Earth. At the time the image was taken, Parker Solar Probe was about 27 million miles from Earth.

The importance of this image is that it demonstrates that the spacecraft’s camera is working properly, and that the spacecraft itself can point accurately.

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Stripes on Dione

2:55 pm

Using data produced by Cassini while orbiting Saturn scientists have discovered long narrow stripes on the moon Dione.

Dione’s linear virgae are generally long (10 to 100s of kilometers), narrow (less than 5 kilometers) and brighter than the surrounding terrains. The stripes are parallel, appear to overlie other features and are unaffected by topography, suggesting they are among the youngest surfaces on Dione.

“Their orientation, parallel to the equator, and linearity are unlike anything else we’ve seen in the Solar System,” Patthoff said. “If they are caused by an exogenic source, that could be another means to bring new material to Dione. That material could have implications for the biological potential of Dione’s subsurface ocean.”

That they cut across the topography implies strongly that they were laid down from above, after the surface irregularities were created.

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Pluto orbiter mission could also explore Kuiper belt

1:16 pm

An analysis by scientists of the orbital mechanics surrounding Pluto and Charon, combined with the use of an ion engine similar to that used by the asteroid probe Dawn, suggests that an orbiter sent to Pluto could also break from from that planet to travel out into the Kuiper Belt and explore additional objects there.

The team first discovered how numerous key scientific objectives can be met using gravity assists from Pluto’s giant satellite, Charon, rather than propellant, allowing the orbiter to change its orbit repeatedly to investigate various aspects of Pluto, its atmosphere, its five moons, and its solar wind interactions for up to several years. The second achievement demonstrates that, upon completing its science objectives at Pluto, the orbiter can then use Charon’s gravity to escape the system without using fuel, slinging the spacecraft into the Kuiper Belt to use the same electric propulsion system it used to enter Pluto orbit to then explore other dwarf planets and smaller Kuiper Belt bodies.

“This is groundbreaking,” said Stern. “Previously, NASA and the planetary science community thought the next step in Kuiper Belt exploration would be to choose between ‘going deep’ in the study of Pluto and its moons or ‘going broad’ by examining smaller Kuiper Belt objects and another dwarf planet for comparison to Pluto. The planetary science community debated which was the right next step. Our studies show you can do both in a single mission: it’s a game changer.”

The key here is a willingness to make increased use of the ion-type engine used by Dawn in its journey from the asteroids Vesta and Ceres. Such a probe could spend decades traveling from one Kuiper Belt object to the next.

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Strong India monsoons cause more hurricane landfalls in North America

10:28 am

A new study has found a correlation between the strength of the monsoon season in India and the number of hurricanes that make landfall in North America.

According to Kelly, La Niña and the Indian monsoon are correlated, but the strength of the monsoon influences the steering of hurricanes independently of La Niña fluctuations, which are responsible for changes in hurricane frequency. In other words, La Niña fluctuations may result in more Atlantic hurricanes, but strong Indian monsoons steer them further westward, making it more likely they will make landfall in the Americas.

It’s important to account for the correlation when studying hurricane steering and landfall probability.

In reading the article, ignore the propaganda promoting global warming, as the research has zero to do with that subject. It instead now provides meteorologists another clue to predicting the frequency and paths of hurricanes in the Atlantic.

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Hubble gyro problem appears fixed

8:18 am

Engineers have apparently pinpointed and fixed the issue that was causing the Hubble Space Telescope’s last back up gyroscope to operate incorrectly, making it likely that the telescope will return to full normal operations shortly.

In an attempt to correct the erroneously high rates produced by the backup gyro, the Hubble operations team executed a running restart of the gyro on Oct. 16. This procedure turned the gyro off for one second, and then restarted it before the wheel spun down. The intention was to clear any faults that may have occurred during startup on Oct. 6, after the gyro had been off for more than 7.5 years. However, the resulting data showed no improvement in the gyro’s performance.

On Oct. 18, the Hubble operations team commanded a series of spacecraft maneuvers, or turns, in opposite directions to attempt to clear any blockage that may have caused the float to be off-center and produce the exceedingly high rates. During each maneuver, the gyro was switched from high mode to low mode to dislodge any blockage that may have accumulated around the float.

Following the Oct. 18 maneuvers, the team noticed a significant reduction in the high rates, allowing rates to be measured in low mode for brief periods of time. On Oct. 19, the operations team commanded Hubble to perform additional maneuvers and gyro mode switches, which appear to have cleared the issue. Gyro rates now look normal in both high and low mode.

This is wonderful news, in that it means the telescope will once again be able to point accurately enough to continue to take sharp images across the entire sky. It also highlights how close we are now to the telescope’s demise, since it no longer has a back-up gyroscope. With the next failure, which will occur eventually, Hubble will descend into one gyroscope operations, holding off its second working gyro as a backup.

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Ariane 5 launches BepiColumbo to Mercury

12:48 am

An Arianespace Ariane 5 rocket successfully launched the joint European/Japanese BepiColumbo mission to Mercury this weekend.

BepiColombo consists of two orbiters: Japan’s Mercury Magnetospheric Orbiter (MMO) and ESA’s Mercury Planetary Orbiter (MPO), both of which will be carried together by the Mercury Transport Module (MTM).

While MPO will go into an approximately 400 x 1500 km mapping orbit around Mercury, MMO will enter a highly elliptical orbit to study the planet’s enigmatically strong magnetic field.

The leaders in the 2018 launch race:

28 China
17 SpaceX
8 Russia
8 ULA
7 Europe (Arianespace)

China still leads the U.S. in the national rankings 28 to 26.

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First interplanetary image from a cubesat

12:39 am

One of the two MarCO cubesats launched with the InSight Mars lander has successfully taken its first picture of Mars, the first such image ever taken by an interplanetary cubesat.

The image itself is not that interesting, with Mars not much more than a dot. What makes this significant is that it proves that a small, inexpensive cubesat can be built with the capability to accurately point and take photographs during an interplanetary mission. This means that the entire field of interplanetary probes is prime for major changes, shifting from big expensive and rarely launched spacecraft to small inexpensive cubesats launching frequently and it large numbers.

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Land of swiss cheese and spiders

12:04 pm

Swiss cheese on Martian south polar cap

Time for some cool images! In one of their periodic captioned releases of an interesting high resolution image, the Mars Reconnaissance Orbiter (MRO) science team this week released a picture of the strange “swiss cheese” terrain found throughout the Martian southern polar cap. (I have already highlighted in an early post the spiders that form in the south pole as the carbon dioxide evaporates.) The image to the right is a cropped section of that image, which you can see in its entirety if you click on it.

The South Polar residual cap is composed of carbon dioxide ice that persists through each Martian summer. However, it is constantly changing shape.

The slopes get more direct illumination at this polar location, so they warm up and sublimate, going directly from a solid state to a gaseous state. The gas then re-condenses as frost over flat areas, building new layers as the older layers are destroyed.

The captioned link above also included a link to a gif animation showing how this terrain has changed since 2009. The holes have become bigger, their cliffs retreating with time.

The section I highlight above not only shows the retreating swiss cheese dry ice, you can also see ghosts of several buried craters slowly becoming visible as the dry ice evaporates away.

This is only one of many images taken of the south pole by MRO. In the October archive release, I found almost two dozen, and that’s only the images taken during August of this summer. MRO takes images of the south pole regularly to track its changes, though I suspect it took more this summer because the global dust storm blocked imagery in the middle latitudes. Below and to the right is just one of these images, a particularly good illustration of the swiss cheese formation.
» Read more

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A new virus that mimics polio appears in U.S.

9:14 am

Not good: Several dozen children in twenty-two U.S. states have been struck by a new polio-like virus that causes paralysis.

Sixty-two AFM cases in 22 states have been confirmed in recent weeks, scientists at the Centers for Disease Control and Prevention (CDC) in Atlanta said at a news conference today; 65 more are under investigation.

Similar waves occurred in 2014 and 2016, and scientists have fingered a relative of the poliovirus, called enterovirus D68 (EV-D68), as a possible culprit. But the evidence isn’t conclusive yet, and it’s unclear why the virus would only paralyze a small minority of children it infects. Solving these mysteries is urgent because the paralysis can be severe and irreversible. AFM is “pretty rare, but it’s pretty devastating,” says Priya Duggal, a genetic epidemiologist at Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, who’s studying whether some patients may have a genetic vulnerability to the virus. “And it appears that it’s cyclical. It’s not going away.”

It appears that in most cases the virus simply causes cold-like symptoms that go away like a cold. In a few cases, however, it produces paralysis.

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Giant planets around young star defy model predictions

8:21 am

The uncertainty of science: The recent discovery of four Saturn/Jupiter-sized planets orbiting a star only about two million years old throws a wrench into all existing solar system formation theories.

The star, CI Tau, is located about 500 light years away in a highly-productive stellar ‘nursery’ region of the galaxy. Its four planets differ greatly in their orbits: the closest (the hot Jupiter) is within the equivalent of the orbit of Mercury, while the farthest orbits at a distance more than three times greater than that of Neptune. The two outer planets are about the mass of Saturn, while the two inner planets are respectively around one and 10 times the mass of Jupiter.

The discovery raises many questions for astronomers. Around 1% of stars host hot Jupiters, but most of the known hot Jupiters are hundreds of times older than CI Tau. “It is currently impossible to say whether the extreme planetary architecture seen in CI Tau is common in hot Jupiter systems because the way that these sibling planets were detected – through their effect on the protoplanetary disc – would not work in older systems which no longer have a protoplanetary disc,” said Professor Cathie Clarke from Cambridge’s Institute of Astronomy, the study’s first author.

According to the researchers, it is also unclear whether the sibling planets played a role in driving the innermost planet into its ultra-close orbit, and whether this is a mechanism that works in making hot Jupiters in general. And a further mystery is how the outer two planets formed at all.

“Planet formation models tend to focus on being able to make the types of planets that have been observed already, so new discoveries don’t necessarily fit the models,” said Clarke. “Saturn mass planets are supposed to form by first accumulating a solid core and then pulling in a layer of gas on top, but these processes are supposed to be very slow at large distances from the star. Most models will struggle to make planets of this mass at this distance.” [emphasis mine]

In other words, the present models are absurdly premature. We simply don’t know enough to formulate any theory that can be taken seriously.

This is not to say that models shouldn’t be formulated, only to emphasize that no one should consider them predictive of any part of reality. They give astronomers some guidance on what to look for, but if they take them too seriously they might not look in the right places.

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Hayabusa-2 will do two touchdown rehearsals prior to landing in January

9:37 am

In order to test whether they can bring Hayabusa-2 down to the surface within a circle only 20 meters (65 feet) across (the largest smooth landing area they have found so far on Ryugu), their engineering team has decided to first do two more touchdown rehearsals in October.

In the area where the spacecraft will touchdown, it is dangerous to have boulders with a height greater than about 50cm. Since the length of the sampler horn is about 1m and the spacecraft will be to be slightly inclined during the touchdown, there is a possibility that if a boulder with a height above about 50cm is present, it will strike the main body of the spacecraft or the solar panels. Viewed from the position in Figure 2, there is no boulder larger than 50cm in the area L08-B. L08-B is the widest part within all the candidate sites without a boulder larger than 50cm.

The difficulty is that area L08-B is only about 20m in diameter. Originally, it was assumed that a safe region for touchdown would be a flat area with a radius of about 50m (100m in diameter). This has now become a radius of just 10m; a fairly severe constraint. On the other hand, during the descent to an altitude of about 50m during the MINERVA-II1 and MASCOT separation operations, we were able to confirm that the spacecraft can be guided within a position accuracy of about 10m for a height 50m above the surface of Ryugu (Figure 3). This is a promising feature for touchdown.

Although the spacecraft can be controlled with a position error of 10m at an altitude down to 50m, there remains the question of whether this accuracy can be retained as the spacecraft descends to the surface. This must be confirmed before touchdown operations. Therefore, the touchdown itself will be postponed until next year, during which time we will have two touchdown rehearsals; TD1-R1-A and TD1-R3.

After the rehearsals in October they must wait until January to do the landing because in November and December the sun will be in-between the Earth and the spacecraft, making operations more difficult. They want to also use this time to review the results of the rehearsals to better prepare for the January landing.

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Curiosity sends down images for the first time in weeks

9:28 am

Good news! For the first time since September 15 Curiosity has sent back images.

The last raw images were received on Sol 2171, equivalent to September 15. Today’s images (Sol 2199) from the front and rear hazard cameras and the two navigation cameras suggest that the engineers have solved the computer issues that prevented the rover from sending its science data to Earth.

No press release has yet been released, but I suspect we shall see something shortly.

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Chandra goes into safe mode

11:43 pm

When it rains it pours: The Chandra X-ray Observatory went into into safe mode on October 10 for reasons that are either not yet understood or have not yet been revealed.

Chandra, Spitzer, and Hubble are the three remaining of the original four great observatories proposed in the late 1980s, with the Compton Gamma-Ray Observatory the fourth. Compton was de-orbited in 2000. Spitzer’s infrared observational capabilities became limited when its cryogenic cooling gas became exhaused in 2009.

Hubble and now Chandra are both in safe mode, leaving astronomy badly crippled.

This situation is actually the fault of the astronomical community, which in the early 2000s put all its money behind the James Webb Space Telescope, leaving little for the construction of replacement space telescopes for either Hubble or Chandra. In addition, the astronomical community has continued to put is money behind similar big, expensive, and giant projects like Webb, pushing for WFIRST with its 2011 decadal survey. Like Webb, WFIRST will cost billions and take almost a decade to build and launch, assuming there are no delays.

Meanwhile, the workhorses in orbit are failing one by one.

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Update on Hubble: no real news

2:15 pm

NASA today released an update on the effort to bring the Hubble Space Telescope out of safe mode and back to full operation.

The only new information they really provide is what they will do, depending on whether they can fix the back up gyroscope or not.

If the team is successful in solving the problem, Hubble will return to normal, three-gyro operations. If it is not, the spacecraft will be configured for one-gyro operations, which will still provide excellent science well into the 2020s, enabling it to work alongside the James Webb Space Telescope and continue groundbreaking science.

In other words, if they cannot find a way to get this third gyro functioning properly, they will shut down one of the two remaining working gyros so that it can operate as a backup, and operate the telescope on one gyroscope.

I find the last section of the quote above very amusing, in a dark sort of way. Not only does NASA rationalize the sad loss of Hubble’s ability to take sharp images, it tries to rationalize the decade-long delays it has experienced building the James Webb Space Telescope. Webb was supposed to have been launched in 2011. It should have been up there already, working alongside Hubble for the past seven years.

Now, the best we can hope for is that Webb will finally reach space while Hubble is still functioning, in a crippled condition. I would not be surprised however if Webb is further delayed, and Hubble is gone before it gets into space.

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MASCOT’s journey on Ryugu

8:31 am

MASCOT's journey on Ryugu

MASCOT’s German science team has released a summary of the lander/hopper’s results and seventeen hour journey across the surface of the asteroid Ryugu. The image on the right, reduced and cropped to post here, shows the spacecraft approach, landing, and numerous hops across the surface. If you click on the image you can see the full high resolution image.

Having reconstructed the events that took place on asteroid Ryugu, the scientists are now busy analysing the first results from the acquired data and images. “What we saw from a distance already gave us an idea of what it might look like on the surface,” reports Ralf Jaumann from the DLR Institute of Planetary Research and scientific director of the MASCOT mission. “In fact, it is even crazier on the surface than expected. Everything is covered in rough blocks and strewn with boulders. How compact these blocks are and what they are composed of, we still do not know. But what was most surprising was that large accumulations of fine material are nowhere to be found – and we did not expect that. We have to investigate this in the next few weeks, because the cosmic weathering would actually have had to produce fine material,” continues Jaumann.

The spacecraft apparently bounced eight times after first contact, then executed three hops. The rubble pile nature that is observed I think explains why the Hayabusa-2 science team decided to delay its own landing for a few months so they could figure out a plan. It really appears that Ryugu does not have any smooth flat spots, as expect.

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Astronomers double the number of known fast radio bursts

9:31 am

Using a radio telescope in Australia astronomers have now doubled the number of known fast radio bursts.

Fast radio bursts come from all over the sky and last for just milliseconds. Scientists don’t know what causes them but it must involve incredible energy—equivalent to the amount released by the Sun in 80 years.

“We’ve found 20 fast radio bursts in a year, almost doubling the number detected worldwide since they were discovered in 2007,” said lead author Dr Ryan Shannon, from Swinburne University of Technology and the OzGrav ARC Centre of Excellence.

In other words, only forty bursts total have ever been detected. The data here however suggests that the bursts are coming from very far away and from the early universe, information which will help scientists figure out what is causing them.

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Hayabusa-2 landing on Ryugu delayed until January

9:22 am

Because of the roughness of the surface of Ryugu, the Hayabusa-2 science team has decided to delay the landing of the spacecraft on the asteroid from the end of this month until late January at the earliest.

JAXA project manager Yuichi Tsuda said they needed more time to prepare the landing as the latest data showed the asteroid surface was more rugged than expected.

“The mission … is to land without hitting rocks,” Tsuda said, adding this was a “most difficult” operation. “We had expected the surface would be smooth … but it seems there’s no flat area.”

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This decision is a wise one. They will have the ability to land very precisely, and this will give them time to find the least risky spot. It does indicate however that the landing itself is going to be risky, which is probably why they want more time to gather data beforehand. Should the landing fail, the mission will essentially be over. This way they can maximize what they learn.

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Ceres’s poles have shifted by as much as 36 degrees

10:31 am

A new analysis of Dawn data suggests that the poles of Ceres have wandered by as much as 36 degrees, and the data also adds further support for the existence of a liquid water layer between the dwarf planet’s crust and mantle.

“The most surprising aspect of this paper is to me the observation that the pole of Ceres must have followed an indirect path to its current pole. A multi-step reorientation could mean that the equatorial density anomaly was still evolving during the reorientation, and this could be because the crust and mantle were weakly rotationally coupled, allowing the crust to start reorienting while the mantle would lag behind,” Tricarico said. “If crust and mantle are allowed to shift with respect to one another, that could point to a layer of reduced friction between crust and mantle, and one of the possible mechanisms to reduce friction could be an ancient water ocean beneath the crust.”

In other words, the crust and mantle are not locked together. Imagine a baseball where the ballcover is not tightly held to the inner core, and slides around it. (Boy there are a lot of pitchers who wish they could get a hand on that baseball.) The cause of that looseness on Ceres is possibly because of a liquid layer in-between the crust and the mantle.

Need I note that there are uncertainties here?

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Sunspot update September 2018: Minimum!

9:58 am

NOAA yesterday released its monthly update of the solar cycle, covering sunspot activity for September 2018. As I have done every month since this website began in July 2011, I am posting it below, annotated to give it some context.

Sunspot activity on the Sun in September dropped slightly from August. More significantly, the activity continues to match closely the weak activity seen in 2008, when the Sun last went through its last solar minimum. We are unquestionably now in the new minimum, and its arrival in the past few months makes the now-ending solar cycle about one to two years shorter than predicted.

September 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.

As I noted last month, the NOAA graph is now getting very close to its right edge, which ends in December 2019. They will very soon have to update this graph so that it can take us into the next solar cycle.

What that new cycle will bring will be the next mystery. I have been following this cycle now since its unusual beginning, with a solar minimum much much longer and more inactive than any solar scientist had ever expected. We can only guess at the surprises the Sun will give us in the coming decade, especially since the science of solar sunspot activity remains superficial and in its infancy. We do not really understand why the Sun’s activity fluctuates. Nor do we understand why it periodically stops producing sunspots for long periods, resulting in what solar scientists call a grand minimum.

There are some scientists who think another grand minimum is coming. We shall have to wait and see. I certainly am going to follow their upcoming observations, as this work remains one of the great scientific studies humans are presently pursuing.

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The central peaks of Copernicus crater

9:41 am

Central peaks of Copernicus Crater

Cool image time! Lunar Reconnaissance Orbiter science team has released a new image of the central peaks of Copernicus Crater, shown on the right cropped and reduced in resolution.

Copernicus (9.62°N, 339.92°E), which is easily seen with a moderately powerful backyard telescope, is one of the best-known craters on the Moon. Despite its age (around 860 million years), it is well preserved with over 4000 meters of relief from floor to rim, and the tallest of its central peaks rises approximately 1300 meters above the crater floor. This image, centered on the central peaks, was captured just after dawn (86° incidence angle) as the Lunar Reconnaissance Orbiter slewed west to a 67°angle.

The image is similar to one taken back in 2012, but has a higher resolution because it was shot from 50 miles elevation instead of 75.

This crater was also the subject of one of the first breath-taking images ever taken of the Moon from lunar orbit, by Lunar Orbiter in November 1966.

The wider view taken by LRO gives some context for the image above. The peaks shown in closeup here are part of the lower right grouping. If you go to the first link above you can zoom in and explore all parts of the full image, and see some quite amazing details, including the large boulders scatter throughout the hollows between the peaks.

Copernicus Crater

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Giant ice pinnacles on Europa

9:15 am

In a new paper scientists note that getting the congressionally mandated Europa Clipper safely to the surface of Jupiter’s moon might be threatened by the existence there of forests of giant five-story high ice pinnacles.

Probes have shown that Europa’s ice-bound surface is riven with fractures and ridges, and new work published today in Nature Geosciences suggests any robotic lander could face a nasty surprise, in the form of vast fields of ice spikes, each standing as tall as a semitruck is long.

Such spikes are created on Earth in the frigid tropical peaks of the Andes Mountains, where they are called “pentinentes,” for their resemblance to devout white-clad monks. First described by Charles Darwin, pentinentes are sculpted by the sun in frozen regions that experience no melt; instead, the fixed patterns of light cause the ice to directly vaporize, amplifying minute surface variations that result in small hills and shadowed hollows. These dark hollows absorb more sunlight than the bright peaks around them, vaporizing down further in a feedback loop.

This work is based on computer models, so it has a lot of uncertainty. It also appears to assume that these pentinentes will be widespread across Europa’s equatorial regions, something so unlikely I find it embarrassing that they even imply it. I guarantee Europa’s surface will be more varied than that. If they are designing Europa Clipper properly, it will go into orbit first to scout out the best landing site, and will be able to avoid such hazards.

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Hubble in safe mode, down to two gyroscopes

8:52 am

The end might be near: The Hubble Space Telescope went into safe mode this weekend when one of its three working gyroscopes failed.

Hubble has six gyroscopes, all of which were replaced by spacewalking astronauts during a servicing mission in May 2009. The telescope needs three working gyroscopes to “ensure optimal efficiency,” mission team members have written, and the failure brings that number down to two (if the “problematic” one that had been off can’t be brought back online).

But that doesn’t mean it’s time to panic. Hubble can do good science with two gyroscopes, or even one, astrophysicist Grant Tremblay, of the Harvard-Smithsonian Center for Astrophysics, said via Twitter Sunday.

While it is true that Hubble can do science on one or two gyroscopes, in that mode it will no longer be able to take the sharp spectacular pictures that represent its great glory.

Hubble was launched in 1990, fixed in 1993, and has been the most successful science robot ever launched. Scientists had hoped, when they made the James Webb Space Telescope their priority in the very early 2000s that both would be in space and operating to provide top notch science data, with Hubble working in visible wavelengths and Webb in the infrared. Webb’s endless delays and cost overruns has now probably made that impossible.

Worse, there are no plans to build a replacement for Hubble. For the first time since 1993, the human race will no longer be able to see, with our own eyes, the universe sharply.

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Data from Voyager 2 suggests it is entering interstellar space

7:50 pm

New data since August from Voyager 2 now suggests it is finally leaving the heliosphere of the solar system and entering interstellar space.

Since late August, the Cosmic Ray Subsystem instrument on Voyager 2 has measured about a 5 percent increase in the rate of cosmic rays hitting the spacecraft compared to early August. The probe’s Low-Energy Charged Particle instrument has detected a similar increase in higher-energy cosmic rays.

Cosmic rays are fast-moving particles that originate outside the solar system. Some of these cosmic rays are blocked by the heliosphere, so mission planners expect that Voyager 2 will measure an increase in the rate of cosmic rays as it approaches and crosses the boundary of the heliosphere.

In May 2012, Voyager 1 experienced an increase in the rate of cosmic rays similar to what Voyager 2 is now detecting. That was about three months before Voyager 1 crossed the heliopause and entered interstellar space.

The scientists warn that there is great uncertainty here, and that the actual transition into interstellar space might take longer than with Voyager 1 since Voyager 2 is traveling in a different direction and is leaving during a different time in the solar cycle.

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