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    Very Large Array Antennas in New Mexico Search for Cosmic Discoveries...

    Giant Antennas in New Mexico Search for Cosmic Discoveries
    September 19, 2017 — Employing an array of giant telescopes positioned in the New Mexico desert, astronomers have started a massive surveying project aimed at producing the most detailed view ever made of such a large portion of space using radio waves emitted from throughout the Milky Way and beyond.
    The National Radio Astronomy Observatory announced the project this week, saying the Very Large Array will make three scans of the sky that's visible from the scrubland of the San Augustin Plains. It is one of the best spots on the planet to scan space, with 80 percent of the Earth's sky visible from the location. The array works like a camera. But instead of collecting light waves to make images, the telescopes that look like big satellite dishes receive radio waves emitted by cosmic explosions and other interstellar phenomenon. Astronomers expect the images gathered by the array will allow them to detect in finer detail gamma ray bursts, supernovas and other cosmic events that visible-light telescopes cannot see due to dust present throughout the universe. For example, the array can peer through the thick clouds of dust and gas where stars are born.

    Scientists involved in the project say the results will provide valuable information for astrophysics researchers. "In addition to what we think [the survey] will discover, we undoubtedly will be surprised by discoveries we aren't anticipating now," project director Claire Chandler said in a statement. "That is the lesson of scientific history and perhaps the most exciting part of a project like this." The survey is possible because of a major technological upgrade at the Very Large Array, which was initially conceived in the 1960s and built in the 1970s. The antennas relied on their original electronics and processing systems for years until a recent overhaul made the system capable of producing much higher resolution images. The work done at the Very Large Array is similar to that of the Hubble Space Telescope — making high-quality images so scientists can better study objects in the universe and the physics of how they work.


    A few of the radio antennas that make up the Very Large Array astronomical observatory, which are positioned on tracks on the Plains of San Augustin west of Socorro, N.M.

    Research efforts elsewhere search the galaxy for signals or evidence of extraterrestrials, but the New Mexico operation would almost certainly get involved if signals are received, said Very Large Array spokesman Dave Finley. "I do think when the time comes that they find a signal that they think is the real thing, the first phone call they will make will be to us. They'll want an image of that region," Finley said. Astronomers using the array also expect to see more examples of powerful jets of superfast particles propelled by the energy of massive black holes at the center of galaxies. This could help in understanding how galaxies grow over time.

    The National Radio Astronomy Observatory in 2013 invited astronomers from around the world to submit ideas and suggestions for the survey. Based on the recommendations, scientists and engineers designed the survey and ran a test in 2016. Approval for the full survey was granted this year. The survey will involve about 5,500 hours of observing time. Data from the three separate scans will be combined to produce the radio images. The scanning began Sept. 7 and the raw data will be available to researchers as quickly as the observations are made. The seven-year project will not come at an additional financial cost because the array already has a $15 million annual budget for making observations 24 hours a day for various scientific requests. More of that time will now be dedicated to the project.

    https://www.voanews.com/a/giant-ante...s/4035897.html
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    Cassini Disintegrates in Saturn's Atmosphere, Ending 20-year Journey
    September 15, 2017 — Tears, hugs and celebrations Friday marked the end of a 20-year mission to Saturn for the spacecraft Cassini.
    In mission control at NASA's Jet Propulsion Laboratory in Pasadena, California, Cassini program manager Earl Maize's voice was heard loud and clear: "The signal from the spacecraft is gone, and within the next 45 seconds, so will be the spacecraft." At a news conference afterward, Maize paid tribute to Cassini. "This morning, a lone explorer, a machine made by humankind, finished its mission 900 million miles away. The nearest observer wouldn't even know until 84 minutes later that Cassini was gone. To the very end, the spacecraft did everything we asked," he said.


    The northern hemisphere of Saturn as seen from the Cassini spacecraft on its descent toward the planet.

    Launched in 1997, Cassini's trip to Saturn took seven years. "When I look back at the Cassini mission, I see a mission that was running a 13-year marathon of scientific discovery, and this last orbit was just the last lap," Cassini project scientist Linda Spilker said.

    Saturn and its moons

    Cassini has been exploring Saturn and some of its moons, making discoveries along the way. "The discoveries that Cassini has made over the last 13 years in orbit have rewritten the textbooks of Saturn, have discovered worlds that could be habitable and have guaranteed that we'll return to that ringed world," Jet Propulsion Laboratory Director Michael Watkins said. Cassini discovered ocean worlds on the Saturn's moons Titan and Enceladus. It also detected strong evidence of hydrothermal vents at the base of Enceladus' ocean. These discoveries prompted the decision to destroy Cassini as it ran out of fuel, so there would be no risk of contaminating these moons with bacteria from Earth.


    Cassini's Amazing Photos of Saturn, Rings & Moons

    In its last hours, Cassini took final images, including Enceladus setting behind Saturn; Saturn's rings; Titan's lakes and seas; and an infrared view of Saturn. As Cassini plunged into Saturn, its sensors experienced the first taste of the planet's atmosphere, sending critical information to Earth until it disintegrated. "It just really tells us about how Saturn formed and the processes going on and really how all the planetary bodies in our solar system have formed," said Nora Alonge, Cassini project science and system engineer.

    Bittersweet moments
    Last edited by waltky; 09-20-2017 at 02:19 AM.

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    So far away it's prob'ly gone by now...

    Farthest monster black hole found
    6 Dec.`17 - Astronomers have discovered the most distant "supermassive" black hole known to science.
    The matter-munching sinkhole is a whopping 13 billion light-years away, so far that we see it as it was a mere 690 million years after the Big Bang. But at about 800 million times the mass of our Sun, it managed to grow to a surprisingly large size such a short time after the origin of the Universe. The find is described in the journal Nature. This relic from the early Universe is busily devouring material at the centre of a galaxy - marking it out as a so-called quasar.


    Quasars are some of the brightest objects in the Universe

    Matter, such as gas, falling onto the black hole will form an ultra-hot mass of material around it known as an accretion disk. "Quasars are among the brightest and most distant known celestial objects and are crucial to understanding the early Universe," said co-author Bram Venemans of the Max Planck Institute for Astronomy in Germany. This quasar is interesting because it comes from a time when the Universe was just 5% of its current age. At this time, the cosmos was beginning to emerge from a period known as the dark ages - just before the first stars appeared. "Gathering all this mass in under 690 million years is an enormous challenge for theories of supermassive black hole growth," said co-author Eduardo Bañados, from the Carnegie Institution for Science.

    The quasar's distance is described by a property called its redshift - a measurement of how much the wavelength of its light is stretched by the expansion of the Universe before reaching Earth. The newly discovered black hole has a redshift of 7.54. The higher the redshift, the greater the distance, and the farther back astronomers are looking in time when they observe the object. Prior to this discovery, the record-holder for the furthest known quasar existed when the Universe was about 800 million years old. "Despite extensive searches, it took more than half a decade to catch a glimpse of something this far back in the history of the Universe," said Dr Bañados.


    The Gemini North observatory was among several involved in the discovery

    The discovery of a massive black hole so early on may provide key clues on conditions that abounded when the Universe was young. "This finding shows that a process obviously existed in the early Universe to make this monster," Dr Bañados explained. "What that process is? Well, that will keep theorists very busy." The unexpected discovery is based on data amassed from observatories around the world. This includes data from the Gemini North observatory on Hawaii's Maunakea volcano and a Nasa space telescope called the Wide-field Infrared Survey Explorer (Wise).

    http://www.bbc.com/news/science-environment-42252235

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    Blue Moon O'er Kentucky...

    January Features Two Supermoons, Blue Moon and Total Lunar Eclipse
    December 31, 2017 - Nature lovers will have their fill of celestial treats in January with two supermoons, a blue moon and a total lunar eclipse gracing the night sky.
    The first supermoon of 2018 will occur on the evening of New Year's Day into the night of Jan. 2. A supermoon occurs when a full moon is at its closet orbital point to Earth, appearing up to 30 percent brighter and up to 14 percent larger than when the moon is at its furthest point in its orbit. Another supermoon will follow on Jan 31, passing by Earth about 26,500 kilometers (16,466 miles) closer than usual. Those two supermoons are part of a trilogy of supermoons that began on Dec. 3. Forecasters say it is rare to have two supermoons back to back, let alone three in a row.

    Scientists say the best time to view a supermoon is right after moonrise and before sunrise, when the moon is sitting on the horizon. This makes the moon look even larger compared to other objects appearing against the night sky, such as buildings and trees. The last full moon of January is also known as a blue moon because it is the second full moon to occur during a single month.


    A full moon, known as the Blue Moon, is seen next to the Statue of Liberty in New York

    The Jan. 31 moon will also feature a total lunar eclipse, with totality visible from western North America across the Pacific to eastern Asia. The moon will appear to be red, and is nicknamed a blood moon, because it lines up perfectly with the Earth and sun such that the Earth’s shadow totally blocks the sun’s light. The moon loses the brightness normally caused by the reflection of the sun's light and takes on an eerie, reddish glow.

    The lunar eclipse will make the Jan. 31 moon a blood moon, a blue moon and a supermoon all at the same time. Unlike a solar eclipse, a lunar eclipse is safe to view with the naked eye, so there is nothing to fear if you are captivated for a long stretch by the night sky.

    https://www.voanews.com/a/january-fe...e/4185393.html

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    'Serious gap' in cosmic expansion rate calls for new physics...

    'Serious gap' in cosmic expansion rate hints at new physics
    11 Jan.`18 - A mathematical discrepancy in the expansion rate of the Universe is now "pretty serious", and could point the way to a major discovery in physics, says a Nobel laureate.
    The most recent results suggest the inconsistency is not going away. Prof Adam Riess told BBC News that an unknown phenomenon, such as a new particle, might explain the deviation. The difference is found when comparing precise measurements of the rate obtained in different ways. However, the statistics are not yet at the threshold for claiming a discovery, Prof Riess, who is based at Johns Hopkins University in Baltimore, Maryland, was one of three scientists who shared the 2011 Nobel Prize in Physics for discovering that the expansion rate of the Universe is accelerating. This phenomenon was widely attributed to a mysterious, unexplained "dark energy" filling the cosmos.

    Values holding

    The unit of measurement used to describe the expansion is called the Hubble Constant, after 20th Century astronomer Edwin Hubble - after whom the orbiting space observatory is named. Appropriately, Prof Riess has been using the Wide Field Camera 3 instrument on the Hubble telescope (installed during the last servicing mission to the iconic observatory) to help refine his measurements of the constant. "The answer we get is 73.24. This is not very different to what people have gotten before measuring the Hubble constant. What is different is that the uncertainty has gotten quite a bit smaller," he said here at the 231st American Astronomical Society meeting in National Harbor, just outside Washington DC. "The uncertainty has been dropping progressively over time, while the value has not been changing very much." To calculate the Hubble Constant, Prof Riess and others use the "cosmic ladder" approach, which relies on known quantities - so-called "standard candles" - such as the brightness of certain types of supernova to calibrate distances across space. However, a different approach uses a combination of the afterglow of the Big Bang, known as the Cosmic Microwave Background (CMB), as measured by the Planck spacecraft and a cosmological model known as Lambda-CDM.


    Artwork: The expansion of the Universe has been accelerating in the billions of years since the Big Bang

    The Hubble Constant obtained using these data is 66.9 kilometres per second per megaparsec. (A megaparsec is 3.26 million light-years, so it follows that cosmic expansion increases by 66.9km/second for every 3.26 million light-years we look further out into space). The gap between the two is now at a confidence level of about 3.4 sigma. The sigma level describes the probability that a particular finding is not down to chance. For example, three sigma is often described as the equivalent of repeatedly tossing a coin and getting nine heads in a row. A level of five sigma is usually considered the threshold for claiming a discovery. However, Prof Riess said that at the three sigma level "this starts to get pretty serious I would say". "In fact, in both cases of measurements, these are very mature measurements... both projects have done their utmost to reduce systematic errors," he added. Indeed, a recent measurement of time delays in quasars that is completely independent of the cosmic distance ladder data gets very similar results to Prof Riess's late Universe Hubble Constant. For the early Universe, a 2017 analysis using the density of baryonic (normal) matter in the cosmos yields a very similar value as the one obtained by the Planck team.


    Variable stars known as cepheids are one of the many "standard candles" used to calibrate cosmic distances

    What this all suggested, he said, was that the Universe is now expanding 9% faster than expected based on the data - a result he described as "remarkable". One way to bridge the divide is to invoke new phenomena in physics. There are various ways to account for it, including the addition of a new particle, called a sterile neutrino, to the Standard Model - the best tested theory of particle physics. The sterile neutrino would represent the fourth type - or flavour - of neutrino; but while the other three are well known to physicists, attempts to detect a fourth with experiments have not come up with much. Another possibility is that dark energy behaves in a different way now compared with how it did in the early history of the cosmos. "One promising way is if we don't have dark matter be so perfectly 'collision-less' but it could interact with radiation in the early Universe," Prof Riess said. He has submitted a paper with his latest analysis of the Hubble Constant for publication in a journal.

    http://www.bbc.com/news/science-environment-42630399

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    Most Distant Star Ever Detected Sits Halfway Across Universe...

    Most Distant Star Ever Detected Sits Halfway Across Universe
    April 02, 2018 | WASHINGTON — Scientists have detected the most distant star ever viewed, a blue behemoth located more than halfway across the universe and named after the ancient Greek mythological figure Icarus.
    Researchers said on Monday they used NASA's Hubble Space Telescope to spot the star, which is up to a million times more luminous and about twice as hot as our sun, residing 9.3 billion lights years away from Earth. It is a type of star called a blue supergiant. The star, located in a distant spiral galaxy, is at least 100 times further away than any other star previously observed, with the exception of things like the huge supernova explosions that mark the death of certain stars. Older galaxies have been spotted but their individual stars were indiscernible.



    NASA’s Hubble Space Telescope image of a blue supergiant star the Icarus, the farthest individual star ever seen, is shown in this image released April 2, 2018. The panels at the right show the view in 2011, without Icarus visible, compared with the star's brightening in 2016.



    The scientists took advantage of a phenomenon called “gravitational lensing” to spot the star. It involves the bending of light by massive galaxy clusters in the line of sight, which magnifies more distant celestial objects. This makes dim, faraway objects that otherwise would be undetectable, like an individual star, visible.


    Peering back in time


    “The fraction of the universe where we can see stars is very small. But this sort of quirk of nature allows us to see much bigger volumes,” said astronomer Patrick Kelly of the University of Minnesota, lead author of the research published in the journal Nature Astronomy. “We will now be able to study in detail what the universe was like — and specifically how stars evolved and what their natures are — almost all the way back to the earliest stages of the universe and the first generations of stars,” Kelly added.


    Because its light has taken so long to reach Earth, looking at this star is like peering back in time to when the universe was less than a third of its current age. The Big Bang that gave rise to the universe occurred 13.8 billion years ago.


    '15 minutes of fame'

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    Milky Way & Anti-matter...

    Milky Way teeming with black holes
    Fri, Apr 06, 2018 - The center of our galaxy is teeming with black holes, sort of like a Times Square for strange super gravity objects, astronomers have discovered.
    For decades, scientists theorized that circling in the center of galaxies, including ours, were lots of stellar black holes, collapsed giant stars where gravity is so strong even light does not get out, but they had not seen evidence of them in the Milky Way core until now. Astronomers poring over old X-ray observations have found signs of a dozen black holes in the inner circle of the Milky Way and since most black holes cannot even be spotted that way, they calculate that there are likely thousands of them. They estimate it could be about 10,000 or more, according to a study in Wednesday’s edition of Nature. “There’s lots of action going on there,” said lead author Chuck Hailey, a Columbia University astrophysicist. “The galactic center is a strange place. That’s why people like to study it.”

    The stellar black holes are in addition to — and essentially circling — the already known supermassive black hole, Sagittarius A, that is at the center of the Milky Way. In the rest of the massive Milky Way, scientists have only spotted about five dozen black holes so far, Hailey said. The newly discovered black holes are within about 30.9 trillion kilometers of the supermassive black hole at the center so there is still a lot of empty space and gas amid all those black holes, but if you took the equivalent space around Earth there would be zero black holes, not thousands, Hailey said. Earth is in a spiral arm about 3,000 light-years away from the center of the galaxy.


    An illustration provided by Columbia University shows the supermassive black hole, Sagittarius A, at the center of the Milky Way surrounded by 12 black holes

    Harvard astronomer Avi Loeb, who was not part of the study, praised the finding as exciting, but confirming what scientists had long expected. The newly confirmed black holes are about 10 times the mass of our sun, as opposed to the central supermassive black hole, which has the mass of 4 million suns. Also the ones spotted are only the type that are binary, where a black hole has partnered with another star and together they emit large amount of X-rays as the star’s outer layer is sucked into the black hole. Those X-rays are what astronomers observe. When astronomers look at closer binary black hole systems they can calculate the ratio between what is visible and what is too faint to be observed from far away.

    Using that ratio, Hailey figures that even though they have only spotted a dozen there must be 300 to 500 binary black hole systems, but binary black hole systems are likely only 5 percent of all black holes, so that means there are really thousands of them. There are good reasons the Milky Way’s black holes tend to be in the center of the galaxy, Hailey said. First, their mass tends to pull them to the center, but mostly the center of the galaxy is the perfect “hot house” for black hole formation, with lots of dust and gas. It is “sort of like a little farm where you have all the right conditions to produce and hold on to a large number of black holes,” Hailey said.

    http://www.taipeitimes.com/News/worl.../06/2003690801
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    Scientists studying mysterious missing anti-matter
    Fri, Apr 06, 2018 - When the universe arose about 13.7 billion years ago, the Big Bang generated matter and anti-matter particles in mirroring pairs. So the reigning physics theory goes.
    Yet everything we can see in the cosmos today, from the smallest insect on Earth to the largest star, is made of matter particles whose anti-matter twins are nowhere to be found. Physicists at Europe’s massive underground particle laboratory on Wednesday said they have taken a step closer to solving the mystery through unprecedented observation of an anti-matter particle they forged in the lab — an atom of “anti-hydrogen.” “What we’re looking for is [to see] if hydrogen in matter and anti-hydrogen in anti-matter behave in the same way,” said Jeffrey Hangst of the ALPHA experiment at the European Organisation for Nuclear Research (CERN). Finding even the slightest difference might help explain the apparent matter, anti-matter disparity and would rock the Standard Model of physics — the mainstream theory of the fundamental particles that make up the universe and the forces that govern them.

    However, somewhat disappointingly, the latest, “most precise test to date,” has found no difference between the behavior of a hydrogen atom and an anti-hydrogen atom. Not yet. “So far, they look the same,” Hangst said in a CERN video. The Standard Model, which describes the makeup and behavior of the visible universe, has no explanation for “missing “anti-matter. It is widely assumed that the Big Bang generated pairs of matter and anti-matter particles with the same mass, but an opposite electric charge. Trouble is, as soon as these particles meet, they annihilate one another, leaving behind nothing but pure energy — the principle that powers imaginary spaceships in Star Trek. Physicists believe matter and anti-matter did meet and implode shortly after the Big Bang, which means the universe today should contain nothing but leftover energy.

    Yet, scientists say that matter, which makes up everything we can touch and see, comprises 4.9 percent of the universe. Dark matter — a mysterious substance perceived through its gravitational pull on other objects — makes up 26.8 percent and dark energy the remaining 68.3 percent. Anti-matter, for all intents and purposes, does not exist, except for rare and short-lived particles created in very high-energy events such as cosmic rays, or produced at CERN. Some theoretical physicists believe the “missing” anti-matter might be found in hitherto unknown regions of the universe — in anti-galaxies comprised of anti-stars and anti-planets.

    At ALPHA, physicists are trying to unravel the mystery using the simplest atom of matter — hydrogen. It has a single electron orbiting a single proton. The team creates hydrogen mirror particles by taking anti-protons left over from the CERN’s high-energy particle collisions and binding them with positrons (the twins of electrons). The resulting anti-hydrogen atoms are held in a magnetic trap to prevent them from coming into contact with matter and self-annihilating. The team then studies the atoms’ reaction to laser light. Atoms from different types of matter absorb different frequencies of light and under the prevailing theory, hydrogen and anti-hydrogen should absorb the same type. So far, it seems they do, but the team hope differences will emerge as the experiment is fine-tuned.

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