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waltky
11-13-2012, 08:58 PM
Granny wonderin' how dey s'posed to find it if ya can't see it?...
:huh:
Quasars illustrate dark energy's roller coaster ride
13 November 2012 - BOSS data is acquired by the 2.5m Sloan telescope at Apache Point Observatory in the US


Scientists have used a novel technique to probe the nature of dark energy some 10 billion years into the past. They hope it will bring them closer to an explanation for the strange force that appears to be driving the Universe apart at an accelerating rate. The method relies on bright but distant objects known as quasars to map the spread of hydrogen gas clouds in space. The 3D distribution of these clouds can be used as a tracer for the influence of dark energy through time. A scholarly paper describing the approach has been submitted to the journal Astronomy & Astrophysics and posted on the arXiv.org preprint site. It is authored by the BOSS (Baryon Oscillation Spectroscopic Survey) team, which uses the 2.5m Sloan Foundation Telescope in New Mexico, US, to make its observations of the sky.

The international group's new data is said to be a very neat fit with theory, confirming ideas that dark energy did not have a dominant role in the nascent Universe. Back then, gravity actually held sway, decelerating cosmic expansion. Only later did dark energy come to the fore. "We know very little about dark energy but one of our ideas is that it is a property of space itself - when you have more space, you have more energy," explained Dr Matthew Pieri, a BOSS team-member. "So, dark energy is something that increases with time. As the Universe expands, it gives us more space and therefore more energy, and at some point dark energy takes over from gravity to end the deceleration and drive an acceleration," the Portsmouth University, UK, researcher told BBC News.

http://news.bbcimg.co.uk/media/images/64099000/jpg/_64099678_64099677.jpg
The BOSS team used 48,000 distant quasars to "back-light" and map the distribution of clouds of hydrogen gas in the early Universe

The discovery that everything in the cosmos is now moving apart at a faster and faster rate was one of the major breakthroughs of the 20th Century. But scientists have found themselves grasping for new physics to try to explain this extraordinary phenomenon. A number of techniques are being deployed to try to get some insight. One concerns so-called baryon acoustic oscillations. These refer to the pressure-driven waves that passed through the post-Big-Bang Universe and which subsequently became frozen into the distribution of matter once it had cooled to a sufficient level. Today, those oscillations show themselves as a "preferred scale" in the spread of galaxies - a slight excess in the numbers of such objects with separations of 500 million light-years.

It is an observation that can be used as a kind of standard ruler to measure the geometry of the cosmos. The BOSS team has already done this using a large volume of galaxies that stretch some six billion light-years from Earth. But at greater distances - and hence deeper in cosmic time - these standard galaxies are simply too faint for the Sloan telescope to see. Instead, the BOSS team has used quasars (quasi-stellar radio sources) to help it map the cosmos. Quasars are far flung galaxies where a massive central black hole is driving the emission of huge amounts of electromagnetic radiation. These are visible to Sloan.

More http://www.bbc.co.uk/news/science-environment-20303592

DonGlock26
11-18-2012, 02:48 PM
Amazing.

waltky
06-24-2016, 01:44 PM
Hubble spots dark vortex on Neptune...
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Hubble locates new dark spot on Neptune
June 23, 2016 - The last several Neptune vortices seen by astronomers have exhibited a wide range of sizes and shapes.


There's a new dark spot on Neptune, the farthest planet from the sun. Astronomers recently confirmed the presence of a dark vortex spinning across the planet's atmosphere after examining imagery collected by the Hubble Space Telescope last month. It's the first Neptune vortex discovered since 1994.

The high pressure system is accompanied by bright companion clouds. Researchers believe the clouds are formed as the vortex pushes ambient air higher into the atmosphere, forcing gases to freeze into methane ice crystals. "Dark vortices coast through the atmosphere like huge, lens-shaped gaseous mountains," Mike Wong, a researcher astronomer at the University of California, Berkeley, said in a news release. "And the companion clouds are similar to so-called orographic clouds that appear as pancake-shaped features lingering over mountains on Earth."


http://cdnph.upi.com/sv/b/i/UPI-6441466711695/2016/1/14667135913639/Hubble-locates-new-dark-spot-on-Neptune.jpg

Wong led the investigation of Hubble data that yielded the discovery of the new dark spot. Jupiter hosts similar cyclone-like disturbances, but the gas giant's vortices are more uniform and sometimes persist, slowly evolving, for decades. Previous studies have proven Neptune's vortices to be a permanent feature, but the disturbances are shorter-lived.

The last several Neptune vortices seen by astronomers have exhibited a wide range of sizes and shapes, and have proven to be relatively unstable -- wandering north and south, speeding up and slowing down. Scientists hope further monitoring of Neptune's vortices will illuminate how they originate and the factors that influence their fluctuations.

http://www.upi.com/Science_News/2016/06/23/Hubble-locates-new-dark-spot-on-Neptune/6441466711695/?spt=sec&or=sn

See also:

‘Dark Vortex’ Spotted on Neptune
June 24, 2016 - The vortex is about the same size as the US


Astronomers have spotted a “dark vortex” swirling in Neptune’s atmosphere. Using high resolution images captured in May by the Hubble Space Telescope, researchers say the vortex is about the size of the continental United States.

The vortex is a high pressure system and is accompanied by bright clouds. In 2015, astronomers spotted clouds and later a dark spot nearby. The May 2016 images confirmed the presence of the vortex. "Dark vortices coast through the atmosphere like huge, lens-shaped gaseous mountains," said University of California at Berkeley research astronomer Mike Wong. "And the companion clouds are similar to so-called orographic clouds that appear as pancake-shaped features lingering over mountains on Earth." Vortices on Neptune have been spotted before. In 1989, the Voyager 2 spacecraft saw one, and in 1994, Hubble pinpointed one.


http://gdb.voanews.com/71519E4C-CE08-45C8-B1F6-48FD6A30E0F1_w640_r1_s.jpg
A dark vortex was spotted on Neptune.

Astronomers say the vortices “have exhibited surprising diversity over the years, in terms of size, shape, and stability (they meander in latitude, and sometimes speed up or slow down).” They also have relatively short lifespans compared to anticyclones seen on Jupiter, which “evolve over decades. Further study should yield a better understanding about how vortices develop, what causes them to move and how they interact with the environment, researchers said. Neptune is roughly 4.3 billion kilometers from the Sun, and it takes 165 Earth years to make one orbit of the sun.

http://www.voanews.com/content/mht-dark-vortex-spotted-on-neptune/3390910.html

Crepitus
06-24-2016, 02:26 PM
Cool info, but as a member of "Friends of Pluto" I must take exception to calling Neptune the farthest planet.

waltky
07-03-2016, 02:52 AM
Granny says, "Dat's right - dem space aliens is havin' a laser light show on Jupiter...
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Bright Lights, Strange Sounds Detected on Jupiter
July 01, 2016 - NASA has released a photo showing glowing auroras on Jupiter.


The image was taken using the Hubble Space Telescope and shows the auroras, which are bigger than Earth, lighting up the gas giant’s poles. While Earth also has auroras, they’re caused by solar storms as opposed to Jupiter’s, which are caused by the massive planet pulling in charged particles from its surroundings as well as the solar winds. "These auroras are very dramatic and among the most active I have ever seen", says Jonathan Nichols from Britain's University of Leicester and principal investigator of the study. "It almost seems as if Jupiter is throwing a firework party for the imminent arrival of Juno." The Juno space probe is days away from a rocket burn that will insert the spacecraft into Jupiter’s orbit later this month.


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This image combines an image taken with Hubble Space Telescope in the optical (taken in spring 2014) and observations of its auroras in the ultraviolet

The probe recently detected odd sounds coming from Jupiter, which NASA describes as a bow shock. “The bow shock is analogous to a sonic boom,” researcher William Kurth of the University of Iowa in Iowa City, said in a NASA news release. “The solar wind blows past all the planets at a speed of about a million miles per hour, and where it hits an obstacle, there’s all this turbulence.” During its mission, Juno will make 37 “close approaches” to Jupiter, and each one could imperil the craft. For example, under the clouds, there is a layer of hydrogen under so much pressure that it conducts electricity. That, along with the planet’s fast rotation [one day on Jupiter is only 10 hours long], creates a strong magnetic field, creating what NASA calls the “harshest radiation environment in the solar system.”

Juno is fitted with “radiation-hardened electrical wiring and shielding” as well as a unique titanium vault that protects the probe’s most vital equipment, such as the flight computer. The vault is so strong that it will reduce radiation exposure by 800 times. Without it, “Juno's electronic brain would more than likely fry before the end of the very first flyby of the planet.” To further mitigate the exposure, Juno’s orbit around the planet will be unusual, as described in the video below.

http://www.voanews.com/content/mht-bright-lights-and-strange-sounds-detected-juno-jupiter/3400199.html

waltky
07-09-2016, 03:19 AM
Odd goin'-ons in outer space...
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Astronomers Spy Giant Planet, Three Stars in Odd Celestial Ballet
July 07, 2016 — Astronomers have discovered a planet unlike any other ever found, one that loops widely around one star that is locked in a gravitational embrace with two others in a triple-star system, creating a curious celestial ballet. The findings, published Thursday in the journal Science, challenge current notions about what makes a planetary system viable.


With three stars in the system, the massive planet would experience triple sunrises and triple sunsets during one season and all daylight in another. Since the planet's orbit is very long, each season lasts for hundreds of years. "Depending on which season you were born in, you may never know what nighttime is like," lead researcher Kevin Wagner of the University of Arizona said. The planet, called HD 131399Ab, is about four times bigger than Jupiter, the largest planet in our solar system, and is orbiting in a three-star system located about 340 light-years from Earth in the constellation Centaurus. Scientists are not sure how HD 131399Ab came to exist. It orbits its parent star about twice as far as Pluto circles the sun, needing 550 years to complete a single orbit.


http://gdb.voanews.com/320544B8-F196-4788-A9C5-2B8B44460136_w640_r1_s_cx0_cy6_cw0.jpg
This artist's impression shows a view of the triple star system HD 131399 from close to the giant planet orbiting in the system. The planet is known as HD 131399Ab and appears at the lower-left of the picture.

Astronomers have previously discovered planets in multi-star systems, but never one that circles a parent star with such a wide berth. It also is one of the few extrasolar planets — those outside our solar system — to be directly imaged by telescope. The planet's orbit is akin to the distance more typically seen when a star orbits another star, not a planet orbiting a star. "This is the first planet that we've found with an orbit that is comparable to that of the stars," Wagner said. If HD 131399Ab's orbit was just a bit wider, computer simulations show it could be gravitationally elbowed out of the system by the pair of smaller stars that orbit each other and the main star, which is about 80 percent bigger than the sun.

Though the planet is relatively young, around 16 million years old compared to the 4.5-billion-year-old Earth, it likely has had an eventful life. Scientists suspect it may have started off in a much closer orbit around two parent stars before it was gravitationally bounced to its extreme distance. Scientists plan additional observations to determine if the planet's orbit is actually stable. "It is not clear how this planet ended up on its wide orbit in this extreme system ... but it shows there is more variety out there than many would have deemed possible," Wagner said. The planet was detected using the European Southern Observatory's Very Large Telescope in northern Chile.

http://www.voanews.com/content/astronomers-spy-giant-planet-three-stars-nasa/3408452.html

See also:

Water Clouds May Float in Dwarf Star’s Atmosphere
July 07, 2016 - Astronomers say they’ve collected evidence that points to the existence of the first water, or water ice, clouds detected outside the solar system.


Writing in the Astrophysical Journal Letters, scientists from the University of California Santa Cruz say the brown dwarf called WISE 0855, which is a mere 7.2 light-years from Earth, likely has the clouds in its atmosphere. Using the Gemini North telescope in Hawaii, researchers scanned WISE 0855, the coldest known object outside the solar system, in the infrared spectrum, which yielded “the first details of the object's composition and chemistry.” "We would expect an object that cold to have water clouds, and this is the best evidence that it does," said Andrew Skemer, assistant professor of astronomy and astrophysics at UC Santa Cruz and first author of the study.

Brown dwarfs are often referred to as failed stars, because they never gained quite enough mass to cause the nuclear fusion reactions that make them shine. WISE 0855 is about five times the mass of the gas giant Jupiter. "WISE 0855 is our first opportunity to study an extrasolar planetary-mass object that is nearly as cold as our own gas giants," Skemer said.


http://gdb.voanews.com/204823D5-D50B-4306-A87E-472B925207B1_w640_r1_s.jpg
Artist's rendering of WISE 0855 as it might appear if viewed up close in infrared light.

Because WISE 0855 is so faint, researchers had to look at “thermal emission from the deep atmosphere at wavelengths in a narrow window” to gain insight into the composition of its atmosphere. "It's five times fainter than any other object detected with ground-based spectroscopy at this wavelength," Skemer said. "Now that we have a spectrum, we can really start thinking about what's going on in this object. Our spectrum shows that WISE 0855 is dominated by water vapor and clouds, with an overall appearance that is strikingly similar to Jupiter."

The two bodies, researchers say, have “strikingly similar” spectra “with respect to water absorption” but that WISE 0855 likely has a less turbulent atmosphere than Jupiter.

http://www.voanews.com/content/mht-water-clouds-may-float-in-dwarf-star-wise0855-atmosphere/3407842.html

Related:

Saturn’s Moon, Titan, Could Support Life
July 06, 2016 - Titan, one of Saturn’s moons, could support a very different kind life, according to a new study.


Writing in the Proceedings of the National Academy of Sciences, researchers from Cornell University say that despite the moon’s harsh environment, a “prebiotic chemical key” likely exists in the form of hydrogen cyanide. The compound is produced when sunlight interacts with the moon’s “toxic” atmosphere made up of nitrogen and methane. The conclusion was reached based on data from NASA’s Cassini and Huygen’s missions.


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Titan is seen from the Huygens probe as it descended to the surface

Hydrogen cyanide is an organic chemical capable of reacting with other molecules, “forming long chains, or polymers, one of which is called polyimine. Polyimine is flexible, which helps mobility under very cold conditions, and it can absorb the sun’s energy and become a possible catalyst for life,” researchers said. “Polyimine can exist as different structures, and they may be able to accomplish remarkable things at low temperatures, especially under Titan’s conditions,” said Martin Rahm, postdoctoral researcher in chemistry and lead author of the new study. This paper is a starting point, as we are looking for prebiotic chemistry in conditions other than Earth’s. “We are used to our own conditions here on Earth. Our scientific experience is at room temperature and ambient conditions. Titan is a completely different beast.”

Other moons in the solar system have also been identified as having conditions that could support life, including Saturn’s Enceladus and Jupiter’s Europa. While both Earth and Titan have flowing liquids in the form of lakes, rivers and oceans, on Titan they are filled with liquid methane and ethane, not water. Also, the moon is too cold to have liquid water. “We need to continue to examine this, to understand how the chemistry evolves over time. We see this as a preparation for further exploration,” said Rahm. “If future observations could show there is prebiotic chemistry in a place like Titan, it would be a major breakthrough. This paper is indicating that prerequisites for processes leading to a different kind of life could exist on Titan, but this only the first step,” he added.

http://www.voanews.com/content/mht-saturns-moon-titan-could-support-life/3406796.html

waltky
09-12-2016, 01:41 AM
Japan's Astro-H satellite Data Adds to Understanding of 'Black Holes'...
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New Data Adds to Understanding of 'Black Holes'
September 12, 2016 | WASHINGTON — Scientists continue to learn more about black holes in space, places where the pull of gravity is so strong that not even light can escape. Black holes occur after supergiant stars explode into brilliant but short-lived supernovas. All the matter dispersed by that titanic explosion collapses in a few weeks or months, and gravity crushes it all into a tiny space. Now, data from a Japanese satellite is helping decipher the secrets of these invisible singularities.


Black holes are invisible to the human eye. But telescopes with special tools can help find them by revealing how they affect nearby stars. In February, Japan’s space agency rocketed its Astro-H satellite into orbit to examine large-scale structures in the cosmos, like supermassive black holes that exist at the center of most galaxies. Unfortunately, after only about a month in space, the satellite fell apart. But before it went out of commission, it was able to gather vital data about the Perseus cluster, consisting of hundreds of galaxies 240 million light years from earth.


On board Astro-H was a unique X-ray spectrometer, which showed that superheated gas at the cluster's heart flows much more calmly than expected. "And that gives us a very precise measurement of how much energy is being pumped into this gas by supermassive black holes, and so it allows us to form a more complete picture of how galaxies evolve, how the stars and the gas that will eventually cool out like rain to form the stars, evolves over cosmic time,” explained Brian McNamara, an astrophysicist at the University of Waterloo in Canada.



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Researchers are also closely looking at the hot plasma—a type of matter--and gases that surround the galaxies. "This is gas that has not cooled out and condensed out like rain in our atmosphere to form stars, planets, life, for example. So it's the potential for the future, and we're trying to understand what the future destiny of this galaxy and many other galaxies would be,” said McNamara.


Supermassive black holes may manipulate how galaxies form and evolve. “The energy released by these giant black holes is very tightly coupled to these atmospheres, which is the stuff out of which future stars will form,” said McNamara. And this means the invisible giant at their heart influences the rate at which a galaxy grows.


http://www.voanews.com/a/new-data-adds-to-understanding-of-black-holes/3503113.html

waltky
09-14-2016, 07:10 AM
Space telescope plots the most precise map ever made of the night sky...
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Gaia space telescope plots a billion stars
Wed, 14 Sep 2016 - Europe's Gaia space telescope releases its first batch of data as it builds the most precise map ever made of the night sky.


The most precise map of the night sky ever assembled is taking shape. Astronomers working on the Gaia space telescope are releasing a first tranche of data recording the position and brightness of over a billion stars. And for some two million of these objects, their distance and sideways motion across the heavens has also been accurately plotted. Gaia's mapping effort is already unprecedented in scale, but it still has several years to run.


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Remarkably, scientists say the store of information even now is too big for them to sift, and they are appealing for the public's help in making discoveries. A web portal has been opened where anyone can play with Gaia data and look for novel phenomena. When a group of schoolchildren showed the BBC how to do it last week, they stumbled across a supernova - an exploded star. The European Space Agency (Esa) launched its Gaia mission in 2013.

Its goal was to update and extend the work of a previous satellite from the 1980s/90s called Hipparcos. This observatory made the go-to Milky Way catalogue for its time - an astonishing chart of our cosmic neighbourhood. It mapped the precise position, brightness, distance and proper motion (that sideways movement on the sky) of 100,000 stars. Gaia, with its first release of data, has just increased that haul 20-fold.

Gaia's imperative - To work out how far it is to the nearest stars (http://www.bbc.co.uk/news/science-environment-37355154)

waltky
01-10-2017, 12:32 AM
Granny says, "Dat's right - Bible says it gonna be daylight at night in Zech. 14...
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Star Explosion Could Change Night Sky
January 09, 2017 - There could be some dramatic changes to the night sky if astronomers are correct in their observations.


They say it may be possible to see a binary star in the Cygnus constellation merge and explode in 2022, creating a red nova. The binary star is about 1,800 light-years away in the Cygnus constellation, so what astronomers are observing now happened about 1,800 years ago. They are making a present day prediction about what may be seen in 2022 based on those observations.

The announcement was made Friday by Lawrence Molnar, professor at Calvin College in Grand Rapids, Michigan, his students, and fellow astronomers from Apache Point Observatory (APO), New Mexico, and the University of Wyoming at the 229th meeting of the American Astronomical Society in Grapevine, Texas. “It is a one-in-a-million chance that you can predict an explosion. It has never been done before,” Molnar said. The binary system, called KIC 9832227, has long been studied, but in 2013, astronomers noticed a change in its brightness. Upon closer inspection, Molnar and his team discovered the stars were getting closer to one another.


https://gdb.voanews.com/5081C573-1A0C-44A5-82E2-D4BA98AD4E95_w250_r1_s.jpg
The Northern Cross of the Cygnus constellation is seen in this stellar map. Astronomers believe two stars in this system are going to collide in five years.

The astronomers then compared that data to an observed creation of a red nova from the binary V1309 Scorpii, which led them to conclude a red nova might be about to form at KIC 9832227. “Bottom line is we really think our merging star hypothesis should be taken seriously right now, and we should be using the next few years to study this intensely so that if it does blow up we will know what led to that explosion,” Molnar said.

If the new red nova does materialize, it will be visible in Cygnus in the prominent formation called the Northern Cross. “The project is significant not only because of the scientific results, but also because it is likely to capture the imagination of people on the street. If the prediction is correct, then for the first time in history, parents will be able to point to a dark spot in the sky and say, ‘Watch, kids, there’s a star hiding in there, but soon it’s going to light up," Matt Walhout, dean for research and scholarship at Calvin College, said.

http://www.voanews.com/a/mht-star-explosion-could-change-night-sky-cygnus-red-nova/3668797.html

resister
01-10-2017, 12:37 AM
I'm tired of spending money on flashlight batteries, anyways.

waltky
09-20-2017, 02:07 AM
Very Large Array Antennas in New Mexico Search for Cosmic Discoveries...
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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.


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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-antennas-new-mexico-search-cosmic-discoveries/4035897.html

See also:

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.


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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.


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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 (https://www.voanews.com/a/cassini-disintegrates-saturn-atmosphere-ending-twenty-year-journey/4031087.html)

waltky
12-06-2017, 05:30 PM
So far away it's prob'ly gone by now...
:shocked:
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.


https://ichef.bbci.co.uk/news/660/cpsprodpb/12FB4/production/_99084777_mediaitem99084776.jpg
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.


https://ichef.bbci.co.uk/news/624/cpsprodpb/8975/production/_99098153_c0019656-gemini_north_telescope_hawaii-spl.jpg
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

waltky
01-01-2018, 04:32 PM
Blue Moon O'er Kentucky...
:cool2:
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.


https://gdb.voanews.com/18A75F03-4A32-45C3-8793-53A71D07EA33_w650_r0_s.jpg
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-features-two-supermoons-blue-moon-and-total-lunar-eclipse/4185393.html

waltky
01-11-2018, 05:06 AM
'Serious gap' in cosmic expansion rate calls for new physics...
:huh:
'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.


https://ichef.bbci.co.uk/news/660/cpsprodpb/12DF9/production/_99550377_universe_expansion_funnel_print.jpg
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.


https://ichef.bbci.co.uk/news/624/cpsprodpb/111E3/production/_99551107_heic1323a.jpg
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

waltky
04-05-2018, 01:53 AM
Most Distant Star Ever Detected Sits Halfway Across Universe...
:cool2:
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.



https://gdb.voanews.com/095DB482-0089-4586-B2D9-198B05A962EB_cx0_cy7_cw0_w1023_r1_s.jpg
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' (https://www.voanews.com/a/most-distant-star-ever-detected-sits-halfway-across-universe/4329865.html)

waltky
04-05-2018, 08:24 PM
Milky Way & Anti-matter...
:cool2:
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.


http://www.taipeitimes.com/images/2018/04/06/P06-180406-325.jpg
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/world/archives/2018/04/06/2003690801

See also:

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.

MORE (http://www.taipeitimes.com/News/world/archives/2018/04/06/2003690802)

waltky
08-06-2018, 11:08 PM
Granny says she ain't visitin' any time soon...
:kiss:
Astronomers Discover New Planet Not Orbiting Any Star
August 06, 2018 - Astronomers have discovered a planet outside our solar system that is 12 times the size of Jupiter, striking not only for its size but also for the fact that it is not orbiting any star.

The so-called "rogue" planet does not revolve around a star, but instead rotates around the galactic center in interstellar space. Astronomers say there have been only a few rogue planets discovered to date. They say even though finding such celestial objects are rare, there could be large amounts of such planets in the universe that have yet to be discovered.



https://gdb.voanews.com/01F2D920-DA8B-46F7-BD03-50A9ECF0FC67_cx0_cy19_cw0_w1023_r1_s.jpg
This April 3, 2017 image made available by NASA shows the planet Jupiter. A newly discovered planet outside our solar system is 12 times the size of Jupiter.



The recently discovered planetary mass was originally found in 2016 but was mistaken for a brown dwarf planet. According to new research published in the Astrophysical Journal, the object is now thought to be a planet in its own right, with an usually strong magnetic field.


Astronomers say the magnetic field of the new planet, named SIMP J01365663+0933473, is more than 200 times stronger than Jupiter's. They say its strong magnetic field likely led to its being detected by a large radio-telescope in New Mexico known as the National Science Foundation's Karl G. Jansky Very Large Array (VLA). The planet is thought to be 200 million years old and is 20 light-years from Earth.


https://www.voanews.com/a/astronomers-discover-new-planet-not-orbiting-any-star/4516684.html