Tag: science

Problems with attitude system doomed Hitomi

12:48 am

A series of failures in the attitude system on Japan’s X-ray space telescope Hitomi led to its destruction.

The problem started when the satellite’s inertial reference unit detected Hitomi was rotating around its Z-axis at 21.7 degrees per hour. The spacecraft was actually stable at the time, mission managers from the Japan Aerospace Exploration Agency said Friday. The satellite’s attitude control system commanded Hitomi’s reaction wheels, rapidly-spinning devices which control the pointing of the spacecraft with momentum, to counteract the spin. The action caused the satellite to rotate in the opposite direction as the faulty inertial reference unit indicated, officials said. Momentum accumulated inside the reaction wheel system, and magnetic torquers aboard the satellite were unable to unload the building momentum, which neared the reaction wheels’ design limit.

Hitomi’s computers recognized the dangerous situation and put the satellite into safe hold a few hours later. The satellite tried to stabilize using the craft’s hydrazine-fueled rocket thrusters to aim its solar panels toward the sun. But the trouble was not over, and the spacecraft’s solar sensor was unable to find the sun. Struggling to correct the growing spin rate, small rocket firings inadvertently caused Hitomi to rotate faster due to a bad setting in the thruster system, JAXA officials said.

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Tetanus boosters can work for almost thirty years

9:17 am

The uncertainty of science: A new study has found that tetanus vaccine booster shots might last three times longer than previously believed.

The study looked for tetanus antibodies in 546 adults who had received the tetanus vaccine at some point in the past. Of those 546 adults, the researchers found that 97 percent still had sufficient antibodies to fight off tetanus. Since tetanus boosters are also designed to fight diphtheria, the same percentage also had antibodies to fight off that disease.

The researchers then looked at the amount of antibodies present in each individual compared to the amount of time that had passed since they received their vaccines. The result was that the study determined the half-life of a tetanus booster to be about 14 years, which means that the average person should be able to go about 28 years between boosters, or almost three times as long as the current CDC recommendation.

The half-life for diphtheria immunity was found to be even longer, at about 27 years, or roughly 54 years between boosters.

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An update on Philae

8:21 am

Link here. No big news. The lander remains silent, and has not yet been precisely located on the surface, though they have a pretty good idea where it is. They expect to get images of it on the surface sometime before September, when Rosetta’s mission will end with its own attempted touchdown on Comet 67P/C-G.

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The asteroid didn’t do it all

12:34 am

The uncertainty of science: A new study adds weight to the theory that the dinosaurs were already in decline when the asteroid hit 65 million years ago.

While some have argued that dinosaurs began petering out some 5 million or 10 million years before their final doom, the new paper suggests it started happening much earlier, maybe 50 million years before the asteroid catastrophe. In terms of species, “they were going extinct faster than they could replace themselves,” said paleontologist Manabu Sakamoto of the University of Reading in England. He led a team of British scientists who analyzed three large dinosaur family trees, looking for evidence of when extinctions began to outnumber the appearances of new species.

They found that starting to happen about 50 million years before the asteroid for most groups of dinosaurs. Two other groups showed increases rather than declines; if their results are included, the overall time for the start of dinosaur decline shrinks to 24 million years before the final demise.

I wrote a science article on this subject back in 1999, and even then the science was far from settled, with most paleontologists strongly arguing that the asteroid was only the final blow and that many other factors, including the big volcano eruption in India about that time, also contributed to the dinosaur’s extinction. That journalists and the planetary science community have pushed the asteroid as the sole factor in that extinction has been a disservice to science. The science has never been that certain.

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Funds needed to identify “Wow!” signal

9:52 am

An astronomer who thinks the “Wow!” radio signal was not from aliens but caused by two comets that were not known at the time is trying to crowd-source the funds he needs to obtain radio telescope time to prove his theory.

Comet 266P/Christensen will pass the Chi Sagittarii star group again on 25 January 2017, while 335P/Gibbs will make its passage on 7 January 2018. Paris plans to observe these events to look for a recurrence of the mystery signal. But time is not on his side for using an existing radio telescope – they are all booked out.

So, he has launched a crowdfunding campaign on gofundme to raise the $13,000 he needs to buy a radio telescope to make the observation. Donations are rolling in and he is already most of the way to his target. “I would like to [be fully funded] in May, order the stuff so that I can have it by October,” he says. This would give him time to construct the dish, test it and prepare for the January encounter.

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More Obamacare exchanges expected to fail

4:30 pm

Finding out what’s in it: Eight of the remaining eleven Obamacare co-op exchanges are expected to default or go out of business before the end of the year, according to a new analysis.

Data compiled by TheDCNF based on the co-op 2015 annual reports suggest eight are likely to default and only four of them will be in business by year’s end. The co-op documents obtained by TheDCNF were annual reports filed before state insurance regulators. The reports must accurately depict the financial health of the co-ops and are current through the end of calendar year 2015. The annual reports became available to the public in mid-March.

More than half of the original 23 co-ops have already gone out of business, leaving hospitals and doctors with millions of dollars of unpaid bills.

Obviously, we must elect Clinton or Sanders, because they want to use the government to do more1

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NOAA plans use of private weather data

9:56 am

The competition heats up: Mandated by Congress to use commercial weather data obtained from privately launched weather satellites, NOAA has announced its first plan for doing so.

The first Commercial Weather Data Pilot, or CWDP, will kick off this summer with a solicitation for GPS radio occultation data of the sort NOAA and Eumetsat have been using for years to improve weather forecasts. GPS radio occultation receivers that have flown on a handful of research satellites and the U.S.-Taiwanese COSMIC constellation obtain highly detailed temperature and humidity soundings by observing tiny distortions of U.S. Air Force GPS signals as they pass through the atmosphere. While the U.S. and Taiwan are preparing to replace the six original COSMIC satellites with the first six of 12 planned satellites slated to launch on a SpaceX Falcon Heavy perhaps late this year, meteorologists would like to see scores of additional GPS radio occultation satellites in orbit.

Several companies, including GeoOptics, PlanetiQ and Spire, have announced plans to address that demand by deploying constellations of dozens to hundreds of small satellites equipped with GPS radio occultation receivers. Spire launched its first four operational satellites last September.

If this goes as I hope, private companies will launch enough satellites to provide the data, at a far lower cost than NOAA spends to build and launch its own satellites, so that eventually it will not pay for the government to do it anymore. Just as private space is replacing NASA in supplying crew and cargo to ISS, private space can do the same for NOAA.

And like NASA initially, NOAA’s managers have been very reluctant to allow this to happen, as it will eventually take the business from them and give it to others. Since they, like NASA, can’t do it very efficiently, however, they can’t really argue their case very well, which is why Congress has been forcing their hand.

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Japanese Venus probe sends back first science data

9:26 am

In a triumph of engineering, the salvaged Japanese Venus probe Akatsuki has beamed back to Earth its first science data.

After an unplanned five-year detour, Japan’s Venus probe, Akatsuki, has come back to life with a bang. On 4–8 April, the Japan Aerospace Exploration Agency (JAXA) presented the first scientific results from the spacecraft since it was rescued from an errant orbit around the Sun and rerouted to circle Venus, four months ago. These include a detailed shot of streaked, acidic clouds and a mysterious moving ‘bow’ shape in the planet’s atmosphere.

Despite the probe’s tumble around the Solar System, its instruments are working “almost perfectly”, Akatsuki project manager Masato Nakamura, a planetary scientist at JAXA’s Institute of Space and Astronautical Science in Sagamihara, Japan, announced at the Inter­national Venus Conference in Oxford, UK. And if another small manoeuvre in two years’ time is successful, he said, the spacecraft might avoid Venus’s solar-power-draining shadow, and so be able to orbit the planet for five years, rather than the two it was initially assigned.

The timing is also good, since Akatsuki is now the only probe circling Venus, and will be for a number of years, until someone else approves, builds, and launches a mission.

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Russian billionaire backs interstellar project

9:00 am

The competition heats up: A Russian billionaire has announced a $100 million investment in an effort to use lasers to propel cellphone-sized spacecraft on an interstellar voyage to Alpha Centauri.

Called Breakthrough Starshot, the programme is based on an idea that has been around for decades: the solar sail. The theory is that a lightweight space sail could harness the momentum carried by photons in order to travel without fuel.

The Breakthrough Starshot team is betting that a burst of concentrated lasers, fired from the ground, could rapidly accelerate a mobile-phone-sized device equipped with microelectronics and a tiny sail — providing much more energy than could be harnessed from the Sun. Whereas NASA’s plutonium-powered New Horizons spacecraft took nine years to reach Pluto, the “nanocraft” envisioned by Breakthrough Starshot would pass by the dwarf planet and exit the Solar System in three days.

The project’s initial US$100-million budget covers only research and development of such a spacecraft. But Breakthrough Starshot’s ultimate goal is to demonstrate proof of concept for an international programme that would send a fleet of nanocraft into space. Doing so would require the group to surmount enormous scientific and engineering challenges in developing the necessary laser technology, materials and communications systems.

This technology is related though not identical to an earlier story about using lasers to power spacecraft.

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Universe’s expansion rate contradicts dark energy data

8:42 am

The uncertainty of science: New measurements of the universe’s expansion rate, dubbed the Hubble constant, contradict theoretical predictions based on previous data.

For their latest paper, Riess’s team studied two types of standard candles in 18 galaxies using hundreds of hours of observing time on the Hubble Space Telescope. “We’ve been going gangbusters with this,” says Riess.

Their paper, which has been submitted to a journal and posted on the arXiv online repository on 6 April, reports that they measured the constant with an uncertainty of 2.4%, down from a previous best result2 of 3.3%. They find the speed of expansion to be about 8% faster than that predicted based on Planck data, says Riess. [emphasis mine]

I highlight the number of galaxies used to get this data because I think these scientists, are being a bit over-confident about the uncertainty of their data. The universe has untold trillions of galaxies. To say they have narrowed their uncertainty down to only 2.4% based on 18 is the height of silliness.

But then, the lead scientist, Adam Riess, recognizes this, as he is also quoted in the article saying “I think that there is something in the standard cosmological model that we don’t understand.”

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Kepler in trouble

9:29 am

Engineers report that the Kepler space telescope went into safe mode about two days ago.

During a scheduled contact on Thursday, April 7, mission operations engineers discovered that the Kepler spacecraft was in Emergency Mode (EM). EM is the lowest operational mode and is fuel intensive. Recovering from EM is the team’s priority at this time.

The mission has declared a spacecraft emergency, which provides priority access to ground-based communications at the agency’s Deep Space Network. Initial indications are that Kepler entered EM approximately 36 hours ago, before mission operations began the maneuver to orient the spacecraft to point toward the center of the Milky Way for the K2 mission’s microlensing observing campaign.

This brief report does not look good. If the spacecraft is in a “fuel intensive” mode, it means it is using extra fuel to survive. This suggests that if they don’t recover it soon it might run out of the fuel and be lost forever.

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Update on Dawn at Ceres

10:07 am

Link here. Though the story initially focuses on the possibility that the mission might be extended a few extra months until the spacecraft’s fuel runs out, it also gives a good summary of what has been learned so far about the dwarf planet, including the theory that Ceres was once an “ocean world.”

[Carol Raymond, Dawn’s deputy principal investigator,] said Ceres appears to be a former ocean world and could have once been similar to Europa or Enceladus, the icy moons of Jupiter and Saturn. “One of the things that we anticipated about Ceres before getting there is that it’s a former ocean world,” Raymond said. “We’re so interested in going to Europa and Enceladus, and these other interesting objects in the outer solar system because we think they harbor subsurface oceans at present, and possible habitable environments, and possibly even locations where there’s extant life.

“Ceres appears to have been one of those objects in the past, when it was younger and hotter,” Raymond said. “What we’re looking at now is, we believe, the remnant of a frozen ocean. The salt is left over from the brines that were concentrated as the ocean froze out, so it’s all a fairly consistent story that Ceres is a former ocean (world) where the ocean froze, and now we’re interrogating the chemistry, essentially, of that ocean-rock interface through the subsurface layers that we’re detecting on Ceres.”

The data has found the high latitudes to have lots of hydrogen, suggesting water-ice on or near the surface. The bright salt patches also suggest frozen water below the surface that left behind the salt when it reached the surface and evaporated away.

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The changing color of Comet 67P/C-G

9:12 am

Data from Rosetta has found that Comet 67P/C-G has changed color and brightness since the spacecraft’s arrival.

Even when Rosetta first rendezvoused with the comet far from the Sun, ices hidden below the surface were being gently warmed, sublimating into gas, and escaping, lifting some of the surface dust away and contributing to the comet’s coma and tail. VIRTIS shows that as the ‘old’ dust layers were slowly ejected, fresher material was gradually exposed. This new surface was both more reflective, making the comet brighter, and richer in ice, resulting in bluer measurements.

On average, the comet’s brightness changed by about 34%. In the Imhotep region, it increased from 6.4% to 9.7% over the three months of observations

The changes are similar to those found on the Moon when the surface there is disturbed. The old surface is very dark. When hit by a meteorite or scrapped by an astronaut’s foot, it brightens. In the case of Comet 67P, the underlying ice pushes outward when heated, the dust is removed, and the surface gets brighter.

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The supernovae that fertilized the Earth

5:45 pm

A new study has pinned down the dates of two recent supernovae that showered the Earth with the heavier elements that make life here possible.

Many mainstream articles about this story have been implying that this research has discovered the existence of supernovae near the primordial Earth. This is false. Scientists have had evidence of these early supernovae for decades, from asteroids, in isotopes on Earth, and in the existence of the Local Bubble in which the Sun is presently traveling. What this study has done is narrow the location and the time of at least two of these supernovae, a significant discovery, though not the one much of the ignorant press is pushing.

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The sunspot decline continues

11:18 am

NOAA’s monthly update of the solar cycle was released today, showing the Sun’s sunspot activity in March. It is annotated and posted below.

March 2016 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.

For the fourth month in a row the change in the graph is so small you almost need a magnifying glass to see it. Despite this, the decline remains remarkably steady, tracking precisely the decline predicted by the low prediction of the 2007 predictions (indicated by the smaller green line curve).

Recently the number of sunspots has dropped enough that I suspect we are not far the moment when we will once again begin to see days where the Sun is blank of sunspots, a situation last seen in 2010 near the end of the previous solar minimum. When that happens, it will herald the beginning of the next solar minimum.

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WISE completes another year of asteroid hunting

9:08 am

After being mothballed in space and then reactivated, NASA’s WISE infrared telescope (renamed NEOWISE for no good reason) has now completed its second year of observations, looking for near-Earth objects (NEOs).

NASA’s Near-Earth Object Wide-field Survey Explorer (NEOWISE) mission has released its second year of survey data. The spacecraft has now characterized a total of 439 NEOs since the mission was re-started in December 2013. Of these, 72 were new discoveries. Near-Earth Objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of the giant planets in our solar system into orbits that allow them to enter Earth’s neighborhood. Eight of the objects discovered in the past year have been classified as potentially hazardous asteroids (PHAs), based on their size and how closely their orbits approach Earth. [emphasis mine]

Unfortunately, the press release does not provide any details about those eight potentially hazardous asteroids.

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Russia denies that Proton upper stage failed after launching ExoMars

9:16 pm

At a press conference today the head of Roscosmos today countered claims that some failure had occurred after ExoMars was placed on its course to Mars.

Briefing reporters in Moscow, Igor A. Komarov reiterated statements made by Proton prime contractor Khrunichev Space Center of Moscow, saying the Breeze-M upper stage separated ExoMars without incident and then proceeded with the standard passivation and collision-avoidance maneuvers.

Komarov said he had seen photos taken from a Brazilian ground telescope that appeared to show small objects in the vicinity of the Breeze-M stage and ExoMars. “I do have these pictures, provided by the Brazilian observatory, showing the ExoMars spacecraft surrounded by some dimly illuminated objects reportedly related to the upper stage,” Komarov said.

“Telemetry and other objectively verifiable data available to us, covering the entire time from the separation and the contamination and collision avoidance maneuvers to the passivation of the upper stage, show that all these steps have been performed successfully, without any anomalies,” Komarov said. “There is absolutely no indication of an upper-stage explosion or breakup.”

The uncertainty will only be settled in the next few weeks, when engineers activate all of ExoMars instruments. Should they all be working as expected, then it will likely be that nothing had happened to the Briz-M upper stage, as Roscosmos claims. If not, then Russia has a problem, since it depends on that stage for future Proton commercial launches and will not know what went wrong here.

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Close encounter with a dust devil

10:14 am

dust devil near Opportunity

Cool image time! On March 31st, as the Mars rover Opportunity took an image of the tracks it left behind as it attempted to climb the steepest slope it has yet attempted, it unexpectedly captured a nearby dust devil. The image to the right is a cropped version of that image

Be sure and take a look at the original image. Not only is the dust devil clearly imaged, showing it to be intense enough that it casts a shadow, the image gives a very good sense of the steepness of that slope. It is not surprising that Opportunity had problems getting up that hill, and eventually had to retreat because it couldn’t get to its target rock formation.

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New Shepard flies again, for the third time

1:23 pm

The competition heats up: On Saturday Blue Origin successfully launched and landed its reusable New Shepard suborbital capsule/rocket spacecraft

The vehicle lifted off from the company’s test site shortly after 11 a.m. Eastern time, according to a series of tweets by company founder Jeff Bezos. The vehicle’s propulsion module, the same one that flew earlier test flights in November and January, made a successful powered landing, he said. Its crew capsule, flying without people on board, parachuted to a safe landing. … The vehicle reached a peak altitude of nearly 103.4 kilometers, slightly above the “von Karman line” frequently used as the boundary of space and similar to previous test flights.

This flight also carried some science experiments, demonstrating that Blue Origin’s customers will not be limited merely to space tourists.

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Opportunity takes a spin

9:36 am

In attempting several times this past week to climb the steepest ever tried by a rover on Mars and failing, Opportunity has moved on to a new less challenging target.

The rover’s tilt hit 32 degrees on March 10 while Opportunity was making its closest approach to an intended target near the crest of “Knudsen Ridge.”

Engineers anticipated that Opportunity’s six aluminum wheels would slip quite a bit during the uphill push, so they commanded many more wheel rotations than would usually be needed to travel the intended distance. Results from the drive were received in the next relayed radio report from the rover: The wheels did turn enough to have carried the rover about 66 feet (20 meters) if there had been no slippage, but slippage was so great the vehicle progressed only about 3.5 inches (9 centimeters). This was the third attempt to reach the target and came up a few inches short.

The rover team reached a tough decision to skip that target and move on.

Having operated thirteen years longer than originally planned, the science and engineering team that operates the Mars rover Opportunity are increasingly willing to try more risky things. For example, the valley the rover is in, called Marathon Valley, is actually an east-west slice through the rim of 14-mile-wide Endeavour Crater. Traveling into that slice towards the crater’s interior is a far riskier trip than ever dreamed of by Opportunity’s designs more than a decade ago.

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Looking back at Comet 67P/C-G

9:27 am

Comet 67P/C-G backlit

Cool image time! As part of its research plan, Rosetta has been moved outward from Comet 67P/C-G for the next few weeks in order to better study its coma and tail. In this new position, engineers were able to maneuver the spacecraft so that it was flying about 600 miles farther from the Sun and could look back and see the Sun being eclipsed by the comet.

Thanks to the combination of a long, four-second exposure, no attenuation filter and a low-gain setting on the analogue signal processor of NAVCAM (a setting that is used to image bright targets), the image reveals the bright environment of the comet, displaying beautiful outflows of activity streaming away from the nucleus in various directions. It is interesting to note hints of the shadow cast by the nucleus on the coma below it, as well as a number of background stars sprinkled across the image.

In the next week the spacecraft will move back in close to the comet.

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White nose syndrome found on Washington state bat

4:08 pm

Bad news for bats: Scientists have confirmed a bat with white nose syndrome in the state of Washington, 1,300 miles further west than the previous detection.

On March 11, hikers found the sick bat about 30 miles east of Seattle near North Bend, and took it to Progressive Animal Welfare Society (PAWS) for care. The bat died two days later, and had visible symptoms of a skin infection common in bats with WNS. PAWS then submitted the bat for testing to the USGS National Wildlife Health Center, which confirmed through fungal culture, molecular and pathology analyses that it had WNS.

I hate to express such a thought, but I can’t help wonder about the legitimacy of this detection. It is so far west and so far from the nearest other bat with white nose syndrome I cannot understand how this bat came to be infected, naturally. In order for this discovery to be confirmed they are going to have to detect it again, and more than once, on a number of bats. Otherwise, it will remain suspect and a possible false positive.

The worst part of this is that the government is surely going to begin instituting draconian measures to protect the bats in Washington, as well as across the entire western United States, even before this detection is confirmed. Having this single detection will make it much easier for government officials to ban humans from many more places, even though white nose syndrome is nowhere close.

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India signs deal for its own LIGO

11:56 am

India today signed an agreement with the National Science Foundation to build its own LIGO gravitational wave detector

This deal, combined with the possibility that TMT might move to India as well, suggests that India is about to move aggressively from the Third World to the First. And the reason, after decades of wallowing in poverty and failure, is that they finally abandoned in the late 1990s the Soviet models of socialism and communism and embraced private enterprise and capitalism, ideas championed by the United States.

If only some modern Americans would do the same.

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Earth forming around sun-like star?

9:51 am

proto-planetary disk

Worlds without end: The ground-based telescope ALMA has imaged a proto-planetary disk around a sun-like star that suggests an exoEarth is forming there the same distance from the star as our Earth is from our Sun.

The star, TW Hydrae, is a popular target of study for astronomers because of its proximity to Earth (approximately 175 light-years away) and its status as a veritable newborn (about 10 million years old). It also has a face-on orientation as seen from Earth. This affords astronomers a rare, undistorted view of the complete disk. “Previous studies with optical and radio telescopes confirm that this star hosts a prominent disk with features that strongly suggest planets are beginning to coalesce,” said Sean Andrews with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and lead author on a paper published today in Astrophysical Journal Letters. “The new ALMA images show the disk in unprecedented detail, revealing a series of concentric dusty bright rings and dark gaps, including intriguing features that suggest a planet with an Earth-like orbit is forming there.”

Other pronounced gap features are located 3 billion and 6 billion kilometers from the central star, similar to the distances from the Sun to Uranus and Pluto in our own Solar System.

The image above right is the inner section of that disk, showing the gap at one astronomical unit, or about 100 million miles from the star, the same as the distance of the Earth from the Sun. Essentially, this relatively close star system is providing us a perfect opportunity to study the formation of a solar system not unlike our own.

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A possible impact on Jupiter?

5:26 pm

On March 17 two different amateur astronomers have taken videos of a bright flash on Jupiter which suggests something had crashed into the gas giant.

March 17th’s impact, if the evidence for it holds up, becomes the fourth such event in the past decade. The largest of these occurred July 19, 2009, and it left a distinctly dark “powder burn” in Jupiter’s upper atmosphere first spotted by Australian astro-imager Anthony Wesley. That was followed by three lesser strikes on June 3, 2010 (recorded independently by Wesley and Christopher Go); on August 10, 2010 (independently seen by Masayuki Tachikawa and Kazuo Aoki); and on September 10, 2012 (seen visually by Dan Petersen and independently recorded by George Hall).

Counting the historic multiple-hit crash of Comet Shoemaker-Levy 9 in July 1994, that’s a grand total of six impacts on Jupiter in the past 22 years.

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Combined Earth-Space radio array discovers superhot quasar interior

11:01 am

The uncertainty of science: Data obtained by combining four ground-based radio telescopes with the Russian orbiting RadioAstron 10-meter radio telescope have detected temperatures of 10 trillion degrees in the quasar 3C 273, a hundred times hotter than predicted possible by theory.

Supermassive black holes, containing millions to billions times the mass of our Sun, reside at the centers of all massive galaxies. These black holes can drive powerful jets that emit prodigiously, often outshining all the stars in their host galaxies. But there is a limit to how bright these jets can be – when electrons get hotter than about 100 billion degrees, they interact with their own emission to produce X-rays and Gamma-rays and quickly cool down.

Astronomers have just reported a startling violation of this long-standing theoretical limit in the quasar 3C 273. “We measure the effective temperature of the quasar core to be hotter than 10 trillion degrees!” comments Yuri Kovalev (Astro Space Center, Lebedev Physical Institute, Moscow, Russia), the RadioAstron project scientist. “This result is very challenging to explain with our current understanding of how relativistic jets of quasars radiate.”

In addition, the higher resolution of the radio images produced by this space/ground-based array was good enough to see the effect produced by the structure of the interstellar material between here and the quasar.

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