Tag: science

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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Sunspot update for May 2017

10:32 am

Last week NOAA posted its monthly update of the solar cycle, covering sunspot activity for May. Unfortunately, there appeared to be a problem with their posting software. Though the date of the image changed, the graph itself was not updated. I contacted NOAA, and Ann Newman, IT Specialist at NOAA’s
Space Weather Prediction Center, took a look and quickly fixed the problem.

The corrected graph is posted below, with annotations, as I have done now every month since 2010.

May 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.

The decline in sunspot activity resumed in May, putting the trend back below the 2007 low prediction. Overall, the trend continues to suggest that this very weak solar maximum will end much earlier than predicted, and will make it an unprecedented short but weak cycle. As the Sun is at this moment blank, and has been for several days, I expect that June will end up with low numbers as well, continuing this trend.

As I have repeatedly said now monthly for six years, if history is any guide, the Sun’s low activity should correspond with cooler temperatures here on Earth. Why this happens is not yet understood, though there are theories.

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Using math to protect the Washington power structure

8:58 pm

What could possible go wrong? A group of mathematicians have written software designed to prevent the gerrymandering of congressional districts, and are offering that software as a weapon for the courts to force states to revise the districts, even though those districts were created by fairly elected state legislatures.

Leaning back in his chair, Jonathan Mattingly swings his legs up onto his desk, presses a key on his laptop and changes the results of the 2012 elections in North Carolina. On the screen, flickering lines and dots outline a map of the state’s 13 congressional districts, each of which chooses one person to send to the US House of Representatives. By tweaking the borders of those election districts, but not changing a single vote, Mattingly’s maps show candidates from the Democratic Party winning six, seven or even eight seats in the race. In reality, they won only four — despite earning a majority of votes overall.

Mattingly’s election simulations can’t rewrite history, but he hopes they will help to support democracy in the future — in his state and the nation as a whole. The mathematician, at Duke University in Durham, North Carolina, has designed an algorithm that pumps out random alternative versions of the state’s election maps — he’s created more than 24,000 so far — as part of an attempt to quantify the extent and impact of gerrymandering: when voting districts are drawn to favour or disfavour certain candidates or political parties.

There are numerous problems here, all of which center on my basic disbelief in the non-partisan objectivity of these scientists and their work.

First, note the first example used. Mattingly proudly shows how his software demonstrates that Democrats could have won more districts in North Carolina. In fact, if you read the article, he claims that the district revisions produced by his software (producing more victorious Democrats) creates fairer districts than the districts created by the state’s fairly elected Republican legislature. Moreover, it was the Republican redistricting that prompted this mathematician to write the software.

Funny how he never felt compelled to do this when it was Democrats controlling the legislatures and gerrymandering the congressional districts to their benefit.

Second, he has offered this software to the courts as evidence to overrule the redistricting done by fairly elected legislatures. In other words, this software will be used to justify letting unelected experts decide how congressional districts should be shaped, not elected officials picked by voters.

Third, note who has expressed interest in using this mathematician as a witness to win its lawsuits:
» Read more

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T Rex fossils suggest it was covered with scales, not feathers

9:04 am

The uncertainty of science: The only known fossils of a T Rex’s skin suggest that the dinosaur was covered with scales, not feathers as recent research has theorized.

[I]f these large tyrannosaurs had any feathers at all, says the team, their fluff would have been limited to their backs—the only body part for which they were lacking fossil impressions. Because their earlier cousins did have feathers, it’s likely that the large tyrannosaurs lost them somewhere along the way, the team suggests.

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Astronomers confirm that comet caused Wow! signal, not aliens

9:01 am

Astronomers have confirmed that the Wow! signal, thought to be the most promising detection by SETI of alien life, was actually caused by a comet.

Last year, a group of researchers from the Center of Planetary Science proposed a new hypothesis that argued a comet might be the culprit. The frequency could be caused by the hydrogen cloud they carry, and the fact that they move accounts for why it seemingly disappeared. Two comets, named 266/P Christensen and P/2008 Y2 (Gibbs), happened to be transiting through that region of space when the Wow! signal was detected, but they weren’t discovered until after 2006.

To test the hypothesis, the team made 200 radio spectrum observations between November 2016 and February 2017. Sure enough, 266/P Christensen was found to emit radio waves at a frequency of 1,420 MHz, and to double check, the researchers moved their radio telescope by one degree. As expected, the signal vanished, and only returned when the telescope was trained back on the comet.

This story demonstrates once again why, in science, it is very dangerous to jump to any conclusions. The data we receive is a mystery. We must keep an open mind to solve that mystery.

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Climate scientists increasingly show no warming in peer review papers

10:19 pm

The uncertainty of science: Climate scientists are increasingly publishing papers that show no clear temperature global trend.

Last year there were at least 60 peer-reviewed papers published in scientific journals demonstrating that Today’s Warming Isn’t Global, Unprecedented, Or Remarkable.

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Just within the last 5 months, 58 more papers and 80 new graphs have been published that continue to undermine the popularized conception of a slowly cooling Earth temperature history followed by a dramatic hockey-stick-shaped uptick, or an especially unusual global-scale warming during modern times.
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Yes, some regions of the Earth have been warming in recent decades or at some point in the last 100 years. Some regions have been cooling for decades at a time. And many regions have shown no significant net changes or trends in either direction relative to the last few hundred to thousands of years.
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Succinctly, then, scientists publishing in peer-reviewed journals have increasingly affirmed that there is nothing historically unprecedented or remarkable about today’s climate when viewed in the context of long-term natural variability. [emphasis in original]

At the link are 80 graphs from the most recent papers. Take a look. If you are convinced that the climate is warming than you must come up with an explanation for this data. Or you can put your fingers in your ears, cover your eyes, and chant “La-la-la-la-la-la-la-la-la-la-la-la-la-la-la-la!” as loud as you can so that you don’t have to deal with it.

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Jupiter gets two more moons

4:51 pm

Astronomers using ground-based telescopes have identified two more moon circling Jupiter, bringing its total now to 69.

Both of these discoveries, as with the vast majority of Jupiter’s moons, occupy retrograde orbits, with inclinations greater than 90°, meaning that they move in directions opposite that of the planet’s spin. These distant, irregular orbits imply that these bodies formed elsewhere in the outer solar system and were captured while passing by early in the planet’s history.

A number of the moons recently discovered have since been lost because their orbits were too poorly constrained. However, some of these lost moons have also be recovered.

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Jupiter’s cloud-tops, up close

4:16 pm

Jupiter's cloud tops

Cool image time! On the right is a cropped and reduced resolution section from this image from Juno. It shows the top of some of Jupiter’s clouds, swirling about chaotically.

What I find most fascinating is how this image reveals the different elevations of some of these cloud belts. The swirling clouds on the left and bottom of the image are clearly higher than the dark areas to the top and right. They are in fact casting their shadows on those lower cloud-tops.

To really understand the interactions taking place here, however, will require satellites capable of continually tracking these clouds over time. Unfortunately, Juno cannot do this. Though it will provide us periodic snapshots of specific areas, its long 53-day orbit means that it will not return to view the same areas very frequently. Making movies of the evolution of these clouds will be difficult, if not impossible.

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More near Earth objects found by WISE

12:05 pm

NASA’s Wide-Field Infrared Explorer (WISE) has released its third year of survey data, including the discovery of 97 previously unknown objects.

Of those, 28 were near-Earth objects, 64 were main belt asteroids and five were comets. The spacecraft has now characterized a total of 693 near-Earth objects since the mission was re-started in December 2013.

For reasons that baffle me, NASA added “Near-Earth Object” to the telescope’s name when they restarted the mission, making its official name now NEOWISE.

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Cumulative data from Curiosity shows Gale Crater lake stratified

12:22 pm

The cumulative data from Curiosity since its arrival on Mars three and a half years ago shows that the lake that once filled Gale Crater lake had had a stratified chemical make-up.

Previous work had revealed the presence of a lake more than three billion years ago in Mars’ Gale Crater. This study defines the chemical conditions that existed in the lake and uses Curiosity’s powerful payload to determine that the lake was stratified. Stratified bodies of water exhibit sharp chemical or physical differences between deep water and shallow water. In Gale’s lake, the shallow water was richer in oxidants than deeper water was.

“These were very different, co-existing environments in the same lake,” said Joel Hurowitz of Stony Brook University, Stony Brook, New York, lead author of a report of the findings in the June 2 edition of the journal Science. “This type of oxidant stratification is a common feature of lakes on Earth, and now we’ve found it on Mars. The diversity of environments in this Martian lake would have provided multiple opportunities for different types of microbes to survive, including those that thrive in oxidant-rich conditions, those that thrive in oxidant-poor conditions, and those that inhabit the interface between those settings.”

While what Hurowitz says above is true, remember that this discovery provides zero evidence of past life on Mars. All it has done is teach us something about the different conditions in the lake at different depths.

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LIGO detects its third gravitational wave

8:22 am

LIGO scientists today revealed that the detector had spotted its third gravitational wave in January.

Researchers estimate that the bodies in the latest collision were slightly lighter than those in the first event: one had the mass of 31 Suns and the other 19. (The black holes in the second discovery were even more lightweight, at 14 and 8 solar masses.) But the latest merger is the most distant detected so far. The gravitational waves it produced took somewhere between 1.6 billion and 4.3 billion years to reach Earth — most probably around 2.8 billion years.

This new field of astronomy should get even more interesting in the next year or two, as new detectors come on line in Italy and Japan.

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Frost on the Moon?

10:37 pm

A new analysis of Lunar Reconnaissance Orbiter data suggests that the coldest spots at the Moon’s south pole are also its brightest, even though they are generally in shadow, suggesting that the surface there might have a thin layer of water frost.

These are also the areas where hydrogen has been detected, which strengthens the theory that this is water.

However, the result is not a positive one for future colonists as it suggests that the amount of water on the Moon is far less than hoped. First, there is this:

The icy deposits appear to be patchy and thin, and it’s possible that they are mixed in with the surface layer of soil, dust and small rocks called the regolith. The researchers say they are not seeing expanses of ice similar to a frozen pond or skating rink. Instead, they are seeing signs of surface frost.

Second, they have not detected this same pattern at the north pole, which strongly suggests that the permanently shadowed areas there do not even have frost.

Overall, this result suggests that the Moon might have water on its surface, but not in great quantities.

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NASA names next solar mission after pioneer solar scientist Eugene Parker

10:31 pm

NASA has named its next solar mission, which will fly closer to the Sun than any previous mission, after pioneer solar scientist Eugene Parker, who in the 1950s predicted the existence of the solar wind.

The new moniker honors pioneering University of Chicago astrophysicist Eugene Parker, who predicted the existence of the solar wind — the stream of charged particles flowing constantly from the sun — back in 1958. [Solar Quiz: How Well Do You Know Our Sun?]

NASA has named about 20 space missions after people; the Hubble Space Telescope is perhaps the most famous example. But the 89-year-old Parker is the first researcher to be celebrated in this manner while still alive, agency officials said.

Parker deserves it, for sure, and it is really nice to honor him while he is still alive to appreciate it.

The spacecraft is scheduled to launch at the end of July.

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Near the Martian south pole

10:06 am

Near the Martian south pole

Cool image time! The image above, reduced and cropped to show here, shows an area at 87 degrees south latitude, not far from the south pole of Mars and in the region at the edge of its icecap of dry ice.

It is late summer in the Southern hemisphere, so the Sun is low in the sky and subtle topography is accentuated in orbital images.

We see many shallow pits in the bright residual cap of carbon dioxide ice (also called “Swiss cheese terrain”). There is also a deeper, circular formation that penetrates through the ice and dust. This might be an impact crater or it could be a collapse pit.

Because of the low Sun angle the bottom of the deep pit is poorly lit, making it hard to determine the pit’s nature. What can be seen at its bottom however are some patches of carbon dioxide ice, melting in the same manner as the dry ice in the surrounding terrain. Also, the dust pattern surrounding the pit indicates the prevailing winds at this location, consistently blowing to the northeast.

I am certain there will be additional photos taken of this pit, when the Sun is higher in the sky and its floor is thus better illuminated.

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Astronomers find star with giant ringed planet

9:30 am

Astronomers now think that a sunlike star about 1,000 light years away dips in brightness every 2.5 years because an orbiting ringed planet or ringed dwarf star blocks the star’s light.

They discovered that every two and a half years, the light from this distant star – PDS 110 in the Orion constellation, which is same temperature and slightly larger than our sun – is reduced to thirty percent for about two to three weeks. Two notable eclipses observed were in November 2008 and January 2011. “What’s exciting is that during both eclipses we see the light from the star change rapidly, and that suggests that there are rings in the eclipsing object, but these rings are many times larger than the rings around Saturn,” says Leiden astronomer Matthew Kenworthy.

Assuming the dips in starlight are coming from an orbiting planet, the next eclipse is predicted to take place in September this year – and the star is bright enough that amateur astronomers all over the world will be able to witness it and gather new data. Only then will we be certain what is causing the mysterious eclipses.

If confirmed in September, PDS 110 will be the first giant ring system that has a known orbital period. [emphasis in original]

Just so no one is confused, this is not Tabby’s Star. There, the dips in light are seemingly random and follow no pattern, other than an overall dimming for the past century.

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Pole of Saturn’s moon Enceladus shifted 55 degrees in the past

2:41 pm

Data from Cassini now suggests that the moon Enceladus shifted its pole as much as 55 degrees sometime in the past, possibly due to an impact.

Whether it was caused by an impact or some other process, Tajeddine and colleagues think the disruption and creation of the tiger-stripe terrain [at south pole] caused some of Enceladus’ mass to be redistributed, making the moon’s rotation unsteady and wobbly. The rotation would have eventually stabilized, likely taking more than a million years. By the time the rotation settled down, the north-south axis would have reoriented to pass through different points on the surface — a mechanism researchers call “true polar wander.”

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Academic invents new non-oppressive physics to protect minorities

10:10 am

This paper is not a prank: A feminist gender studies academic from the University of Arizona has invented a theory of “intersectional quantum physics” to fight the oppression of Newtonian physics.

Whitney Stark argues in support of “combining intersectionality and quantum physics” to better understand “marginalized people” and to create “safer spaces” for them, in the latest issue of The Minnesota Review. Because traditional quantum physics theory has influenced humanity’s understanding of the world, it has also helped lend credence to the ongoing regime of racism, sexism and classism that hurts minorities, Stark writes in “Assembled Bodies: Reconfiguring Quantum Identities.”

What is also important is that this college researcher, who also has an appointment in the culture and gender studies department at Utrecht University in the Netherlands, got her paper published in a journal published by Duke University Press. Below is her full abstract. I dare you to tell me what it means.

In this semimanifesto, I approach how understandings of quantum physics and cyborgian bodies can (or always already do) ally with feminist anti-oppression practices long in use. The idea of the body (whether biological, social, or of work) is not stagnant, and new materialist feminisms help to recognize how multiple phenomena work together to behave in what can become legible at any given moment as a body. By utilizing the materiality of conceptions about connectivity often thought to be merely theoretical, by taking a critical look at the noncentralized and multiple movements of quantum physics, and by dehierarchizing the necessity of linear bodies through time, it becomes possible to reconfigure structures of value, longevity, and subjectivity in ways explicitly aligned with anti-oppression practices and identity politics. Combining intersectionality and quantum physics can provide for differing perspectives on organizing practices long used by marginalized people, for enabling apparatuses that allow for new possibilities of safer spaces, and for practices of accountability.

I also dare you to build a rocket using this new physics. I also wonder if anyone can tell the difference between this legitimate paper and this fake one.

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Curiosity data increases time water existed Gale Crater

9:45 am

New research using data from Curiosity has found evidence suggesting that significant water was present in Gale Crater for a very long time.

Lighter-toned bedrock that surrounds fractures and comprises high concentrations of silica — called “halos”— has been found in Gale crater on Mars, indicating that the planet had liquid water much longer than previously believed. The new finding is reported in a new paper published today in Geophysical Research Letters, a journal of the American Geophysical Union.

“The concentration of silica is very high at the centerlines of these halos,” said Jens Frydenvang, a scientist at Los Alamos National Laboratory and the University of Copenhagen and lead author of the new study. “What we’re seeing is that silica appears to have migrated between very old sedimentary bedrock and into younger overlying rocks. The goal of NASA’s Curiosity rover mission has been to find out if Mars was ever habitable, and it has been very successful in showing that Gale crater once held a lake with water that we would even have been able to drink, but we still don’t know how long this habitable environment endured. What this finding tells us is that, even when the lake eventually evaporated, substantial amounts of groundwater were present for much longer than we previously thought—thus further expanding the window for when life might have existed on Mars.”

The actual paper provides no time frame. What it does state is that for the halos to have formed requires a lot of time, and that during that time a lot of groundwater was required.

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Dog sits on editorial board of seven medical journals

4:16 pm

An Australian professor wondered if he could get his dog Ollie picked to be on the editorial board of a number of medical journals, and was astonished to discover seven who agreed without reservations.

Ollie’s owner is Mike Daube, Professor of Health Policy at Curtin University in Perth. Ollie likes to watch Mike working on his computer, and Mike gets a lot of emails from predatory journals. Wondering just how low these journals would go, he put together a curriculum vitae for his dog – detailing research interests such as “the benefits of abdominal massage for medium-sized canines” – and sent it off to a number of these journals, asking for a spot on their editorial boards.

Remarkably, the vast majority accepted Ollie without demur, and her name now adorns several journal websites. Ollie is a trailblazer, Professor Daube says, being the first dog ever to get on the editorial board of a journal.

“What makes it even more bizarre is that one of these journals has actually asked Ollie to review an article. It’s entitled “Malignant peripheral nerve sheath tumours and their management.” Some poor soul has actually written an article on this theme in good faith, and the journal has sent it to a dog to review.”

The article provides a nice look at the problems facing the modern peer review journal field.

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Brewing beer on the Moon

10:41 am

Capitalism in space: A student experiment to attempt to brew beer on the Moon, rejected by one Google Lunar X-Prize contestant, has been accepted by another.

The experiment involves a small canister that, once on the moon, will mix yeast with wort, the mixture of barley and other ingredients that give beer its flavor, to cause fermentation and carbonation. Besides proving that beer can be brewed remotely and in low gravity, the experiment demonstrates the potential for making other things involving yeast in low gravity, such as bread and certain medicines, which could be important if a lunar colony is ever established.

The canister, designed by the students at the Qualcomm Institute Prototyping Facility, will be aboard a spacecraft being built by Synergy Moon, one of the teams competing for the Google Lunar XPrize, a contest meant to inspire engineers and entrepreneurs to develop low-cost methods of robotic space exploration..

They have also been accepted to fly the experiment on several Synergy Moon orbital flights.

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Looking at Jupiter’s southern hemisphere

9:43 am

Jupiter's southern hemisphere

Cool image time! The image on the right, reduced to post here, shows Jupiter’s south pole and much of its southern hemisphere. It was taken during Juno’s last orbital fly-by of the gas giant’s cloud tops last week, and has been enhanced by Fevig-58, an ordinary citizen who downloaded the raw image and then uploaded his enhanced version to the Juno website.

It is definitely worthwhile taking a close look at the full resolution image. At the top its shows the horizontally banded Jupiter at equatorial- and mid-latitudes that has been that planet’s familiar face for centuries. In the middle is the transitional region from those horizontal bands to the chaotic polar regions. And at the bottom is the pole, where there the storms appear to follow no pattern and form a mish-mash.

One thing about Jupiter’s pole. It appears very different than Saturn’s. While I am certain they will find a vortex of some kind there, so far there is no indication of a coherent jet stream, as seen by Saturn’s hexagon. This once again demonstrates the one unbroken rule of planetary science that has been found with every planetary mission to every planetary body, whether they be pebbles, asteroids, dwarf planets, gas giants, or moons: Every single one of them is different and unique. They might fall into a single category, say gas giants, but each has its own unique features that make it different from every other member of that category.

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First science results from Juno

11:48 am

The Juno science team today released their first research results since the spacecraft entered orbit around Jupiter in July 2016.

“Although many of the observations have terrestrial analogs, it appears that different processes are at work creating the auroras,” said SwRI’s Dr. Phil Valek, JADE instrument lead. “With JADE we’ve observed plasmas upwelling from the upper atmosphere to help populate Jupiter’s magnetosphere. However, the energetic particles associated with Jovian auroras are very different from those that power the most intense auroral emissions at Earth.”

Also surprising, Jupiter’s signature bands disappear near its poles. JunoCam images show a chaotic scene of swirling storms up to the size of Mars towering above a bluish backdrop. Since the first observations of these belts and zones many decades ago, scientists have wondered how far beneath the gas giant’s swirling façade these features persist. Juno’s microwave sounding instrument reveals that topical weather phenomena extend deep below the cloudtops, to pressures of 100 bars, 100 times Earth’s air pressure at sea level.

“However, there’s a north-south asymmetry. The depths of the bands are distributed unequally,” Bolton said. “We’ve observed a narrow ammonia-rich plume at the equator. It resembles a deeper, wider version of the air currents that rise from Earth’s equator and generate the trade winds.”

Juno is mapping Jupiter’s gravitational and magnetic fields to better understand the planet’s interior structure and measure the mass of the core. Scientists think a dynamo — a rotating, convecting, electrically conducting fluid in a planet’s outer core — is the mechanism for generating the planetary magnetic fields. “Juno’s gravity field measurements differ significantly from what we expected, which has implications for the distribution of heavy elements in the interior, including the existence and mass of Jupiter’s core,” Bolton said. The magnitude of the observed magnetic field was 7.766 Gauss, significantly stronger than expected. But the real surprise was the dramatic spatial variation in the field, which was significantly higher than expected in some locations, and markedly lower in others. “We characterized the field to estimate the depth of the dynamo region, suggesting that it may occur in a molecular hydrogen layer above the pressure-induced transition to the metallic state.”

What I want to see is a depth map showing where Jupiter’s atmosphere ends and its solid core begins. I expect Juno will eventually be able to give us a first glimpse.

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Star becomes black hole without supernova explosion

10:20 am

The uncertainty of science: Astronomers think they have identified a star that, rather than die and become a black hole in a supernova explosion, merely fizzled into a black hole.

Starting in 2009, one particular star in the Fireworks Galaxy, named N6946-BH1, began to brighten weakly. By 2015, it appeared to have winked out of existence. The astronomers aimed the Hubble Space Telescope at the star’s location to see if it was still there but merely dimmed. They also used the Spitzer Space Telescope to search for any infrared radiation emanating from the spot. That would have been a sign that the star was still present, but perhaps just hidden behind a dust cloud.

All the tests came up negative. The star was no longer there. By a careful process of elimination, the researchers eventually concluded that the star must have become a black hole.

There are a lot of uncertainties here. Nonetheless, astronomers have theorized that some stars could collapse into black holes with any explosions, and it appears they might have found their first example of that.

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After 7 years Cassini reaches Saturn’s solstice

3:55 pm

In 2010 NASA extended the Cassini mission orbiting Saturn for seven years to the planet’s next solstice, so that the spacecraft could observe Saturn, its moons, and its rings, for one full season of its 28 year orbit.

Today, Cassini reached that target.

NASA’s Cassini spacecraft still has a few months to go before it completes its mission in September, but the veteran Saturn explorer reaches a new milestone today. Saturn’s solstice — that is, the longest day of summer in the northern hemisphere and the shortest day of winter in the southern hemisphere — arrives today for the planet and its moons. The Saturnian solstice occurs about every 15 Earth years as the planet and its entourage slowly orbit the sun, with the north and south hemispheres alternating their roles as the summer and winter poles.

The article provides a detailed review of all the changes that have occurred during this long time period.

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The face of Ceres

9:35 am

The face of Ceres

Cool image time! The image on the right, reduced in resolution to show here, was taken by Dawn on April 29, 2017, when the spacecraft had been positioned between the Sun and the dwarf planet at a moment when its entire surface was lit. They have enhanced the colors to bring out the contrasts.

Images combining these different color filter perspectives reveal fine details of Ceres’ surface. For example, they emphasize the distinct compositions and textures of the material ejected from craters. The brightest region on Ceres, called Cerealia Facula, is highlighted in Occator Crater in the center of this image. Vinalia Faculae, the set of secondary bright spots in the same crater, are located to the right of Cerealia Facula.

One of the darkest regions on Ceres is next to Occator, and represents ejected material from the impact that formed the crater. The ejected material forms a large arc that extends over several hundred kilometers, below the center of Ceres in this image. That material’s distribution is partly determined by Ceres’ rotation.

Be sure to take a close look at the full image. It isn’t super high resolution, but it reveals a lot of interesting details

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