Tag: science

Mars rover update: July 12, 2017

2:49 pm

Summary: Curiosity looks at some big dune ripples, then creeps up hill. Opportunity tests its wheels.

Curiosity

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

The interior of a dune ripple

Since my last update on June 23,, Curiosity has worked its way around and, for a few days, even into the small sandy field at the base of Vera Rubin ridge. The scientists noticed that the sandy here had a series of large ripples, and they wanted to take a close look at at least one. The image on the right, cropped to show here, was taken shortly after they had the rover drive through one ripple in order to expose its interior. You can see the robot arm directly above the cut created by the rover’s wheels. On the cut’s wall several distinctly different toned layers are visible. A close look reveals that they are wavy, and probably indicate numerous and repeated overlays as the wind brushes a new layer of dust on top of old layers, time after time. The different tones indicate a change in the material’s composition, which could reveal something about some past events in either Mars’ weather or geology.

In order to decipher this information, however, they will need to be able to date the layers, and figure out when each tonal change happened. I am not sure Curiosity can do this, especially since they have not scooped up any of this dust for later analysis.

They are now approaching Vera Rubin Ridge, and should climb up onto in the coming weeks. At that point they will move off the Murray Formation, where they have been since March 2016, made up of dried and ancient crushed mud, and up onto a lighter, yellowish layer of rock, dubbed the Hematite Unit. This October 3, 2016 press release. gives a good outline of the geology of these regions.
» Read more

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ESA unveils dual orbiter mission to Mercury

10:31 am

After twenty years of development, the European Space Agency this week finally unveiled the completed dual orbiters that it hopes to launch on a seven year journey to Mercury in October 2018.

The 4,100-kilogram BepiColombo consists of two orbiters that will launch together — the ESA-managed Mercury Planetary Orbiter (MPO) and the JAXA-owned Mercury Magnetospheric Orbiter (MMO). The two spacecraft will be delivered to the orbit around Mercury stacked on top of each other by the Mercury Transfer Module (MTM). During the seven-year journey, the MMO will be shielded from the sun by the MMO Sunshield and Interface Structure (MOSIF), which will also serve as a mechanical and electrical interface between the two orbiters.

“MPO focuses on the planet, the surface and the interior size,” said Reininghous. “The orbit is a polar one — 480km times approximately 1500km — a little bit elliptical but extremely close to the planet as such with a return period of 2.3 hours. The data return is estimated at 1.5 gigabit per year.”

The MMO will focus on the planetary environment including the planet’s atmosphere, according to Reininghous. “The orbit is also polar but far more elliptical — 590 km times approximately 11,700 km. It has a period of 9.3 hours. The data return is approximately 10 percent of what we expect from the MPO.”

The European orbiter is much larger and more expensive, with Japanese probe budget being about a tenth the cost.

According to ESA, the mission took so long to build because in 2004, after about seven years of development, ESA suddenly realized that its orbiter’s thermal protection was inadequate, and required a complete redesign. To me, this is either outright incompetence (they knew from the start they were going to Mercury) or a clever way to extend the funding so that it provides an entire lifetime’s work for its builders. Think about it. Twenty-one years from concept to launch, then seven years to fly to Mercury, and then one to two years in orbit. That’s more than thirty years for this single mission.

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New Horizons’ next target might be smaller than predicted

10:43 am

The uncertainty of science: Because all attempts to observe an occultation of a star on June 3 by New Horizons’ next target failed, astronomers now think Kuiper Belt object 2014 MU69 is much smaller than previously believed.

The discovery observations using Hubble and other ground-based telescopes had estimated its size as between 12 to 25 miles in diameter. The null result from the June 3 event suggests it is smaller than that.

More occultations are upcoming, so stay tuned.

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Fastest stars in Milky Way escaped from Large Magellanic Cloud?

9:01 am

Astronomers have proposed that the fastest stars in Milky Way actually escaped from the Large Magellanic Cloud (LMC), the largest nearby satellite dwarf galaxy.

The LMC is the largest and fastest of the dozens of dwarf galaxies in orbit around the Milky Way. It only has 10% of the mass of the Milky Way, and so the fastest runaways born in this dwarf galaxy can easily escape its gravity. The LMC flies around the Milky Way at 400 kilometres per second and, like a bullet fired from a moving train, the speed of these runaway stars is the velocity they were ejected at plus the velocity of the LMC. This is fast enough for them to be the hypervelocity stars. “These stars have just jumped from an express train – no wonder they’re fast,” said co-author Rob Izzard, a Rutherford fellow at the Institute of Astronomy. “This also explains their position in the sky, because the fastest runaways are ejected along the orbit of the LMC towards the constellations of Leo and Sextans.”

Their calculations predict how many hypervelocity stars should be detectable and where in the sky they should be. If right, the data from Gaia, soon to be released, should prove them right or wrong.

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New data suggests Sun undergoing fundamental changes

8:40 am

The uncertainty of science: New data, when compared with similar data collected over decades, suggests the Sun’s solar cycle is undergoing some fundamental changes.

In work just published in the Monthly Notices of the Royal Astronomical Society, the team shows that the interior of the Sun has changed in recent years, and that these changes persist in the current cycle. In combination with theoretical models, the observations suggest that the magnetic field distribution in the outer layers may have become a bit thinner. Other seismic data shows that the rotation rate of the Sun has also undergone some changes in the way the Sun rotates at different latitudes.

“Again, this is not how it used to be and the rotation rate has slowed a bit at latitudes around about 60 degrees. We are not quite sure what the consequences of this will be but it’s clear that we are in unusual times. However, we are beginning to detect some features belonging to the next cycle and we can suggest that the next minimum will be in about two years,” says Elsworth.

First, they don’t know what will happen because of these changes. Second, their data confirms that the solar minimum will occur in about two years, which would make this cycle only 9 years long, one of the shortest but also one of the weakest that has been observed, two things that previously had never gone together.

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Sunspot update for June 2017

11:47 am

Today NOAA posted its monthly update of the solar cycle, covering sunspot activity for June. As I have done every month since 2010, the graph is posted below, with annotations.

June 2017 Solar Cycle graph

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.

Sunspot activity in June was almost exactly the same as in May, and thus continued the overall downward trend that is below the 2007 low prediction and that suggests that this very weak solar maximum will end much earlier than predicted, and will make it an unprecedented short but weak cycle. The Sun is once again blank today for the first time in about two weeks, repeating the pattern we have seen for several months where, because one hemisphere of the Sun is blank while the other hemisphere has some sunspots, the rise and fall of the sunspot counts tracks the 27-day solar rotation almost precisely.

There continues to be evidence that the Sun is undergoing significant changes this solar cycle, all of which are pointing to the possibility that a grand minimum is coming, with no sunspots for decades. And as I have said now monthly for six years, past grand minimums have consistently occurred at the same time the Earth’s climate has cooled. The scientific link remains unclear, but if we should undergo a grand minimum in the coming decades, we will finally have the opportunity to find out what that link is.

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The soft craters of Epimetheus

9:24 am

The soft craters of Epimetheus

Cool image time! The image on the right, reduced in resolution to show here, is the highest resolution image that Cassini has taken of the Saturn moon Epimetheus, taken from only 9,300 miles away on February 21, 2017.

Epimetheus (70 miles or 113 kilometers across) is too small for its gravity to hold onto an atmosphere. It is also too small to be geologically active. There is therefore no way to erase the scars from meteor impacts, except for the generation of new impact craters on top of old ones.

Below is the inset at full resolution, showing several craters, with ponds of dust on their floor. Overall, the surface of this tiny moon looks soft. The craters are all shallow, as if any impact merely plunged into a blob of ice cream. Any ejecta from those impacts eventually rained back down, and then settled slowly in the moon’s low points, forming those ponds of dust.

close-up of soft craters

In many ways this image is very revealing, as it shows what the early accretion process of any planetary body will look like. Nor is this unique. Earlier images taken of the asteroid Eros by the NEAR probe saw many of these same features, as have images of Saturn’s other small moons. In the early stages, new material gets absorbed easily because it finds it easy to bore into the body of the newly formed and not very dense planetary body. There isn’t much ejecta, and what there is doesn’t fly that far away so that it can settle back down on the surface and add to the new body’s total mass.

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As predicted climate scientists begin adjusting satellite data to fit models

12:37 pm

If the facts don’t fit the theory, change the facts! The scientists in charge of the climate satellite data produced by Remote Sensing Services (RSS) in California have decided to adjust their satellite data to increase the warming trend since 2000 and make that data more closely match the surface temperature data that NASA and NOAA have already altered to show that same warming trend.

Researchers from Remote Sensing Systems (RSS), based in California, have released a substantially revised version of their lower tropospheric temperature record. After correcting for problems caused by the decaying orbit of satellites, as well as other factors, they have produced a new record showing 36% faster warming since 1979 and nearly 140% faster (i.e. 2.4 times larger) warming since 1998. This is in comparison to the previous version 3 of the lower tropospheric temperature (TLT) data published in 2009.

How have they done this? They made several changes, the first two of which appear quite questionable. First, they addressed the “time of observation issue.” There is a belief among some climate scientists that the time temperature readings were taken can introduce an error in the long term trends.

To account for changes in observation times, the RSS group used a number of different approaches and models to try and estimate what the temperature would have been if the measurement time remained constant. This involves a combination of satellite observations (when different satellites captured temperatures in both morning and evening), the use of climate models to estimate how temperatures change in the atmosphere over the course of the day, and using reanalysis data that incorporates readings from surface observations, weather balloons and other instruments.

Depending on the time of the observation correction approach chosen, the resulting temperature trends between 1979 and 2016 ranged from as low as 0.13C per decade to as high as 0.22C per decade. The RSS group ultimately decided that the most reasonable set of parameters give a temperature trend of 0.17C. [emphasis mine]

I am puzzled by this, since satellites in orbit do not take readings at one particular time, but at a wide range of times. In fact, I would say that the number of readings, at all different times, would easily introduce enough randomness into the results that any error would be insignificant. Instead, these scientists have decided to adjust the raw data to add a warming trend of almost a tenth of a degree centigrade.

Next, they simply decided that the data coming from some satellites should be excluded.
» Read more

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Astronomers take best image of Betelgeuse yet

5:21 pm

Betelqeuse

Using the Atacama Large Millimeter/submillimeter Array Telescope (ALMA), astronomers have produced the best picture of the red giant star Betelgeuse taken so far.

Using ESO’s Very Large Telescope astronomers discovered a vast plume of gas almost as large as our Solar System. Astronomers have also found a gigantic bubble that boils away on Betelgeuse’s surface. These features help to explain how the star is shedding gas and dust at tremendous rates (eso0927, eso1121). In this picture, ALMA observes the hot gas of the lower chromosphere of Betelgeuse at sub-millimeter wavelengths — where localised increased temperatures explain why it is not symmetric.

The image on the right is that image, slightly reduced to post here. The bulge on the star’s left illustrates the unevenness of the star’s upper atmosphere. I suspect that continuous observations would reveal the outer atmosphere waxing and waning almost like the stuff inside a lava lamp.

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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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Uranus’s magnetic field switches on and off daily

9:54 am

Using data from the Voyager 2 flyby of Uranus in 1986, scientists now think that the gas giant’s magnetic field switches on and off each day as the planet rotates.

Uranus’s magnetosphere, in contrast [to Earth], exhibits precise regularity in its mode changes. This, say the researchers, is because it lies at an angle of roughly 60 degrees to the planet’s spin axis, causing its interaction with incoming solar winds to vary dramatically during the 17 hours it takes for a full rotation. “Uranus is a geometric nightmare,” says Paty.

“The magnetic field tumbles very fast, like a child cartwheeling down a hill head over heels. When the magnetised solar wind meets this tumbling field in the right way, it can reconnect and Uranus’s magnetosphere goes from open to closed to open on a daily basis.”

The researchers suggest the robust and regular changes to the magnetosphere may mean that the icy planet has spectacular auroras across its breadth every day.

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Orbital motion of a binary black hole detected for the first time

10:19 am

Astronomers have for the first time measured the orbital motion of two supermassive black holes that orbit each other.

Based on the initial data, the two black holes appear to orbit each other every 30,000 years. Eventually, they will spiral into each other, merge, and in the process produce ripples in the surrounding gravitational field that will be detectable by future gravitational wave detectors.

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Success of test mission paves way for orbiting gravitational wave detector

9:57 am

The success of LISA Pathfinder during the past year to test the technology for building an orbiting gravitational wave detector has now made it possible for Europe to approve construction of the full scale telescope, set to launch in the 2030s.

The LISA Pathfinder mission, launched in late 2015, beat its precision target by a factor of 1,000 and quieted critics who have doubted its potential, says project scientist Paul McNamara, an astrophysicist at ESA in Noordwijk, the Netherlands. “This is not the impossible task that some people believed it was.”

Currently set to fly in 2034, the full-scale Laser Interferometer Space Antenna (LISA) will be the space analogue of the Laser Interfero-meter Gravitational-Wave Observatory (LIGO), two machines in the United States — each with a pair of 4-kilometre-long arms — that first detected the ripples by ‘hearing’ the merger of two black holes. LISA’s three probes will fly in a triangle, millions of kilometres apart, making the mission sensitive to much longer gravitational waves, such as the ripples produced by the collisions of even larger black holes.

The article also notes that the European Space Agency also approved two other large missions, one to launch in 2022 and go the moons of Jupiter, another an X-ray observatory that will launch in 2028.

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Climate scientists once again claim ozone layer is threatened

9:40 am

Crying wolf! New research by climate scientists suggests that the Earth’s ozone layer is once again threatened by modern human technology.

Industrial emissions of a chemical commonly used in solvents, paint removers, and the production of pharmaceuticals have doubled in the past few years, researchers have found, which could slow the healing of the ozone layer over Antarctica anywhere between 5 and 30 years—or even longer if levels continue to rise.

The findings are “frightening” and “a big deal,” says Robyn Schofield, an environmental scientist at the University of Melbourne in Australia who was not involved with the work.

They might be right, but why should anyone believe them? The climate field has been spouting doomsday predictions about global warming and sea level rise now for more than 20 years, none of which have come true. As far as I can tell, this might be more of the same thing.

Worse, it might not, but by not being honest with so many other climate predictions the field has lost all political credibility, a great tragedy for them and for all of science. It will take decades, if ever, for them to recover that credibility.

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Mars rover update: June 23, 2017

11:11 am

Summary: Curiosity continues up hill. Opportunity has wheel problems.

Curiosity

For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.

The march up Mt Sharp continues. Since my last update on May 15, Curiosity has continued working its way up towards what the science team has named Vera Rubin Ridge, the beginning of a lighter, yellowish layer of rock, dubbed the Hematite Unit, that sits higher up the mountain’s slope. They have been traveling on the Murray Formation now for more than a year, since March, 2016, so entering this new layer of geology is eagerly anticipated by the science team. (This October 3, 2016 press release. gives an overall picture of the geology Curiosity is traversing.)

Reader Phil Veerkamp sent me a beautiful panorama he stitched together from recent Curiosity images of Vera Rubin Ridge, directly to the south of the rover and higher up hill. Below is a reduced resolution version. Be sure you click on it to explore the full resolution image. This is a new type of terrain, significantly different than anything Curiosity has seen up to now. It also appears that the rover will see far less dust, and might be traveling mostly over solid boulders. Below I have cropped out a very small section of the ridge line near the center of the full image, just to illustrate this.
» Read more

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Warp in Kuiper Belt suggests existence of Mars-sized object

8:40 am

The uncertainty of science: Astronomers think they have identified a warp in the Kuiper Belt that suggests a Mars-sized object exists there, affecting the orbits of surrounding objects.

According to the calculations, an object with the mass of Mars orbiting roughly 60 AU from the sun on an orbit tilted by about eight degrees (to the average plane of the known planets) has sufficient gravitational influence to warp the orbital plane of the distant KBOs [Kuiper Belt Objests] within about 10 AU to either side. “The observed distant KBOs are concentrated in a ring about 30 AU wide and would feel the gravity of such a planetary mass object over time,” Volk said, “so hypothesizing one planetary mass to cause the observed warp is not unreasonable across that distance.”

This proposed planet is not the theorized Planet Nine that other astronomers have proposed. That planet, which hasn’t been found and other data says doesn’t exist, would be much larger and much farther out.

I would add that neither of these proposed planets might exist. At this moment our data of the Kuiper Belt is very incomplete. I would not bet much on any theory that extrapolates planets from what we presently know.

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Trump administration continues to clean house at EPA

9:14 am

The Trump administration this week announced that it will not renew the appointment of 38 scientists to a key EPA science panel.

All board members whose three-year appointments expire in August will not get renewals, Robert Kavlock, acting head of EPA’s Office of Research and Development, said in the email, which was obtained by E&E News.

Because of the need to reconstitute the board, EPA is also canceling all subcommittee meetings planned for late summer and fall, Kavlock said. “We are hopeful that an updated BOSC Executive Committee and the five subcommittees can resume their work in 2018 and continue providing ORD with thoughtful recommendations and comments,” he wrote in urging departing members to reapply.

As the article notes, some Democratic pigs are squealing over this, but the Trump administration is only following the law. And considering how political and anti-business the EPA has become in recent years, a full review of all committee members seems entirely appropriate and reasonable.

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Recent Kuiper Belt discoveries cast doubt a big planet exists there

9:03 am

The uncertainty of science: Despite predictions by some scientists that a big planet exists in the Kuiper Belt beyond Neptune, recent new discoveries of new objects there cast doubt on its existence.

If the additional big planet existed, the newly discovered objects would have shown some clustering, shepherded by its gravity.

“We find no evidence of the orbit clustering needed for the Planet Nine hypothesis in our fully independent survey,” says Cory Shankman, an astronomer at the University of Victoria in Canada and a member of the Outer Solar System Origins Survey (OSSOS), which since 2013 has found more than 800 objects out near Neptune using the Canada-France-Hawaii Telescope in Hawaii. In a paper posted to arXiv on 16 June and soon to be published in The Astronomical Journal, the OSSOS team describes eight of its most distant discoveries, including four of the type used to make the initial case for Planet Nine.

“I think it’s great work, and it’s exciting to keep finding these,” says Scott Sheppard, an astronomer at the Carnegie Institution for Science in Washington, D.C., who was among the first to suspect a large planet in the distant solar system. But he says three of the four new objects do have clustered orbits consistent with a Planet Nine. The fourth, an object called 2015 GT50, seems to skew the entire set of OSSOS worlds toward a random distribution. But that is not necessarily a knockout blow, he says. “We always expected that there would be some that don’t fit in.”

Note that I do not consider “Planet Nine” to be an accurate name for this theorized planet. Either it is #10, after Pluto, or one of a large number far more than nine, based on a new proposed and more logical planetary definition. The present definition however does not work.

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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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Update of Kepler exoplanet catalog

9:44 am

Worlds without end: The Kepler science team has released an update of the space telescope’s exoplanet candidate list, adding 219 new exoplanet candidates.

NASA’s Kepler space telescope team has released a mission catalog of planet candidates that introduces 219 new planet candidates, 10 of which are near-Earth size and orbiting in their star’s habitable zone, which is the range of distance from a star where liquid water could pool on the surface of a rocky planet. This is the most comprehensive and detailed catalog release of candidate exoplanets, which are planets outside our solar system, from Kepler’s first four years of data. It’s also the final catalog from the spacecraft’s view of the patch of sky in the Cygnus constellation.

With the release of this catalog, derived from data publicly available on the NASA Exoplanet Archive, there are now 4,034 planet candidates identified by Kepler. Of which, 2,335 have been verified as exoplanets. Of roughly 50 near-Earth size habitable zone candidates detected by Kepler, more than 30 have been verified.

Additionally, results using Kepler data suggest two distinct size groupings of small planets. Both results have significant implications for the search for life. The final Kepler catalog will serve as the foundation for more study to determine the prevalence and demographics of planets in the galaxy, while the discovery of the two distinct planetary populations shows that about half the planets we know of in the galaxy either have no surface, or lie beneath a deep, crushing atmosphere – an environment unlikely to host life.

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How cats used humans to conquer the world

8:42 am

Link here. The bottom line is this:

Compared to many other animals, cats have also changed very little in the domestication process. Behaviorally, they’ve become more tolerant of humans. Physically, though, they’re still about the same size and shape. They still like to pounce on small prey. “Cats have done since before they were domesticated what we needed them to do,” says Leslie Lyons, a feline geneticist at the University of Missouri. In other words, unlike dogs that herd sheep or hunt badgers, cats didn’t need humans to breed them to become good mouse hunters.

In other words, cats did what they want (as they always do), and humans paid them with food and companionship, while providing them the transportation they needed to reach every continent.

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Titan’s clearing northern skies

11:10 am

Titan's clearing northern skies

The image of Titan on the right, reduced in resolution to show here, was taken by Cassini less than a week ago, on June 9, as it continues its last orbits of Saturn prior to crashing into the gas giant’s atmosphere in September.

NASA’s Cassini spacecraft sees bright methane clouds drifting in the summer skies of Saturn’s moon Titan, along with dark hydrocarbon lakes and seas clustered around the north pole. Compared to earlier in Cassini’s mission, most of the surface in the moon’s northern high latitudes is now illuminated by the sun. …Summer solstice in the Saturn system occurred on May 24, 2017.

When Cassini arrived more than a decade ago, it was winter on Titan’s northern hemisphere, and the atmosphere was thick with haze. Now the sky is clearing as the stormy weather shifts to the winter in the southern hemisphere.

As with yesterday’s global map of Mimas, this image is in many ways a farewell look at Titan. While Cassini will likely get a few more global images of the Saturn moon before the mission ends in September, this image essentially marks the end of our ability to observe this strange planet closely, for decades to come. When Cassini crashes into Saturn, our vision at Saturn will go blind. And no one knows when our sight there will return, as no mission is presently in the works, or is even being considered, to return to Saturn.

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Digitizing Venice’s 1,000-year-old archives

9:53 am

Link here. The article describes an ambitious effort to make this archive, much of which has never been read, easily accessible and searchable using modern digital technology.

As Venice’s empire grew, it developed administrative systems that recorded vast amounts of information: who lived where, the details of every boat that entered or left the harbour, every alteration made to buildings or canals. Modern banking was invented in the Rialto, one of Venice’s oldest quarters, and notaries there recorded all trading exchanges and financial transactions.

Crucially, those records survived through turbulent centuries. While the rest of Europe was roiled by its perpetually warring monarchs, from the eighth century onwards Venice began to develop into a stable republic that provided the peace and order required for trade to flourish. In many ways it was a model democracy. The people elected a leader — the doge — supported by various councils, whose members were also usually elected. Governance was secular, but for the most part co-existed tolerantly with religion.

French emperor Napoleon Bonaparte put an end to the Serene Republic in 1797. En route to Vienna during his attempt to conquer the Austro-Hungarian Empire, he declared Venice’s secular and democratic governance to be a form of autocracy, and the city to be an enemy of the revolution. He forced the republic to dissolve itself. In 1815, the old Frari was turned into the State Archives of Venice. Over the next decades, all state administrative documents, including death registers, were transferred there, along with medical records, notary records, maps and architectural plans, patent registers and a miscellany of other documentation, some from elsewhere in Italy. Particularly significant are ambassadors’ reports from wider Europe and the Ottoman Empire, providing a unique source of detailed information about daily life. “Venetian ambassadors were the most observant travellers, trained to find out things like what was being unloaded at the docks, or what a prince or other high-up was like as a person,” says Daston. “Their reports were full of gossip and intrigue.”

Most of the archive, predominantly written in Latin or the Venetian dialect, has never been read by modern historians. Now it will all be systematically fed into the Venice Time Machine, along with more unconventional sources of data, such as paintings and travellers’ logs.

Venice is a particularly important component of European history, as in many ways it was the last remnant of the Roman Empire, founded by Romans even as their empire was collapsing around them. It then lasted almost a thousand years, and became throughout the Middle Ages a powerful and important center of European trade. Moreover, the growth of this strange city in a bog is in many ways a mystery. This archive will actually allow researchers and historians to finally begin to understand how these events unfolded.

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China launches X-ray space telescope

9:35 am

China today launched the Hard X-ray Modulation Telescope (HXMT), also dubbed Insight by Chinese news sources.

The HXMT carries three x-ray telescopes observing at energies ranging from 20 to 200 kilo-electron volts as well as an instrument to monitor the space environment, according to its designers. While orbiting 550 kilometers above the planet, the HXMT will perform an all-sky survey that is expected to discover a thousand new x-ray sources. Over an expected operating lifetime of 4 years, it will also conduct focused observations of black holes, neutron stars, and gamma ray bursts.

More here. This is China’s first home-grown X-ray space telescope, and its launch once again illustrates that, for at least the next few decades, China intends to be a major player in the exploration of the solar system.

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A new map of Mimas

9:36 am

Global map of Mimas

The Cassini science team has released what will be the best map of Saturn’s moon Mimas for many decades to come. A reduced resolution version is above, and was updated after the most recent fly-bys in November 2016 and February 2017.

The moon’s large, distinguishing crater, Herschel, is seen on the map at left. The map is an equidistant (simple cylindrical) projection and has a scale of 710 feet (216 meters) per pixel at the equator. The mean radius of Mimas used for projection of this map is 123.2 miles (198.2 kilometers). The resolution of the map is 16 pixels per degree.

Since Cassini is in its final orbits and will crash into Saturn in September, and no other Saturn mission is even being planned, do not expect a better map for a very long time.

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China to attempt to grow potatoes on Moon

9:22 am

China’s Chang’e-4 lunar rover/lander, set to launch in 2018, will include a small experiment that will attempt to grow potatoes from seeds.

Note that I have just realized that I have been confusing Chang’e-5 with Chang’e-4. Chang’e-5 is a sample return mission that they hope to launch this year. It does not include a rover. Chang’e-4 is a lander/rover mission that is planned for 2018.

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Worm grows 2 heads on ISS

5:29 pm

The uncertainty of science: For reasons that are not yet understood, a flatworm fragment flown to ISS in a microgravity experiment regenerated with two heads.

But the most dramatic difference was a type of regeneration observed in one of the 15 worm fragments sent to the ISS. That worm returned to the scientists with two heads (one on each end of its body), a type of regeneration so rare as to be practically unheard of — “normal flatworms in water never do this,” Levin told Live Science. When the researchers snipped both heads off back on Earth, the middle portion regenerated into a two-headed worm again.

“And these differences persist well over a year after return to Earth!” Levin said. “Those could have been caused by loss of the geomagnetic field, loss of gravity, and the stress of takeoff and landing — all components of any space-travel experience for living systems going to space in the future,” he said.

The flatworms that flew in space showed other significant differences from the control group that stayed on Earth, further suggesting that for flatworms at least the environment of weightlessness causes more problems that were expected.

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