Space news topic and space related news

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Toliman


Toliman

Possible Marker of Life Spotted on Venus
https://www.eso.org/public/news/eso2015/

An international team of astronomers today announced the discovery of a rare molecule — phosphine — in the clouds of Venus. On Earth, this gas is only made industrially or by microbes that thrive in oxygen-free environments. Astronomers have speculated for decades that high clouds on Venus could offer a home for microbes — floating free of the scorching surface but needing to tolerate very high acidity. The detection of phosphine could point to such extra-terrestrial "aerial" life.

"When we got the first hints of phosphine in Venus's spectrum, it was a shock!", says team leader Jane Greaves of Cardiff University in the UK, who first spotted signs of phosphine in observations from the James Clerk Maxwell Telescope (JCMT), operated by the East Asian Observatory, in Hawaiʻi. Confirming their discovery required using 45 antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, a more sensitive telescope in which the European Southern Observatory (ESO) is a partner. Both facilities observed Venus at a wavelength of about 1 millimetre, much longer than the human eye can see — only telescopes at high altitude can detect it effectively.

The international team, which includes researchers from the UK, US and Japan, estimates that phosphine exists in Venus's clouds at a small concentration, only about twenty molecules in every billion. Following their observations, they ran calculations to see whether these amounts could come from natural non-biological processes on the planet. Some ideas included sunlight, minerals blown upwards from the surface, volcanoes, or lightning, but none of these could make anywhere near enough of it. These non-biological sources were found to make at most one ten thousandth of the amount of phosphine that the telescopes saw.

To create the observed quantity of phosphine (which consists of hydrogen and phosphorus) on Venus, terrestrial organisms would only need to work at about 10% of their maximum productivity, according to the team. Earth bacteria are known to make phosphine: they take up phosphate from minerals or biological material, add hydrogen, and ultimately expel phosphine. Any organisms on Venus will probably be very different to their Earth cousins, but they too could be the source of phosphine in the atmosphere.

While the discovery of phosphine in Venus's clouds came as a surprise, the researchers are confident in their detection. "To our great relief, the conditions were good at ALMA for follow-up observations while Venus was at a suitable angle to Earth. Processing the data was tricky, though, as ALMA isn't usually looking for very subtle effects in very bright objects like Venus," says team member Anita Richards of the UK ALMA Regional Centre and the University of Manchester. "In the end, we found that both observatories had seen the same thing — faint absorption at the right wavelength to be phosphine gas, where the molecules are backlit by the warmer clouds below," adds Greaves, who led the study published today in Nature Astronomy.

Another team member, Clara Sousa Silva of the Massachusetts Institute of Technology in the US, has investigated phosphine as a "biosignature" gas of non-oxygen-using life on planets around other stars, because normal chemistry makes so little of it. She comments: "Finding phosphine on Venus was an unexpected bonus! The discovery raises many questions, such as how any organisms could survive. On Earth, some microbes can cope with up to about 5% of acid in their environment — but the clouds of Venus are almost entirely made of acid."

The team believes their discovery is significant because they can rule out many alternative ways to make phosphine, but they acknowledge that confirming the presence of "life" needs a lot more work. Although the high clouds of Venus have temperatures up to a pleasant 30 degrees Celsius, they are incredibly acidic — around 90% sulphuric acid — posing major issues for any microbes trying to survive there.

ESO astronomer and ALMA European Operations Manager Leonardo Testi, who did not participate in the new study, says: "The non-biological production of phosphine on Venus is excluded by our current understanding of phosphine chemistry in rocky planets' atmospheres. Confirming the existence of life on Venus's atmosphere would be a major breakthrough for astrobiology; thus, it is essential to follow-up on this exciting result with theoretical and observational studies to exclude the possibility that phosphine on rocky planets may also have a chemical origin different than on Earth."

More observations of Venus and of rocky planets outside our Solar System, including with ESO's forthcoming Extremely Large Telescope, may help gather clues on how phosphine can originate on them and contribute to the search for signs of life beyond Earth.

Toliman

ESO telescope spots galaxies trapped in the web of a supermassive black hole
https://www.eso.org/public/news/eso2016/

With the help of ESO's Very Large Telescope (VLT), astronomers have found six galaxies lying around a supermassive black hole when the Universe was less than a billion years old. This is the first time such a close grouping has been seen so soon after the Big Bang and the finding helps us better understand how supermassive black holes, one of which exists at the centre of our Milky Way, formed and grew to their enormous sizes so quickly. It supports the theory that black holes can grow rapidly within large, web-like structures which contain plenty of gas to fuel them.

"This research was mainly driven by the desire to understand some of the most challenging astronomical objects — supermassive black holes in the early Universe. These are extreme systems and to date we have had no good explanation for their existence," said Marco Mignoli, an astronomer at the National Institute for Astrophysics (INAF) in Bologna, Italy, and lead author of the new research published today in Astronomy & Astrophysics. 

The new observations with ESO's VLT revealed several galaxies surrounding a supermassive black hole, all lying in a cosmic "spider's web" of gas extending to over 300 times the size of the Milky Way. "The cosmic web filaments are like spider's web threads," explains Mignoli. "The galaxies stand and grow where the filaments cross, and streams of gas — available to fuel both the galaxies and the central supermassive black hole — can flow along the filaments."

The light from this large web-like structure, with its black hole of one billion solar masses, has travelled to us from a time when the Universe was only 0.9 billion years old. "Our work has placed an important piece in the largely incomplete puzzle that is the formation and growth of such extreme, yet relatively abundant, objects so quickly after the Big Bang," says co-author Roberto Gilli, also an astronomer at INAF in Bologna, referring to supermassive black holes.

The very first black holes, thought to have formed from the collapse of the first stars, must have grown very fast to reach masses of a billion suns within the first 0.9 billion years of the Universe's life. But astronomers have struggled to explain how sufficiently large amounts of "black hole fuel" could have been available to enable these objects to grow to such enormous sizes in such a short time. The new-found structure offers a likely explanation: the "spider's web" and the galaxies within it contain enough gas to provide the fuel that the central black hole needs to quickly become a supermassive giant.

But how did such large web-like structures form in the first place? Astronomers think giant halos of mysterious dark matter are key. These large regions of invisible matter are thought to attract huge amounts of gas in the early Universe; together, the gas and the invisible dark matter form the web-like structures where galaxies and black holes can evolve.

"Our finding lends support to the idea that the most distant and massive black holes form and grow within massive dark matter halos in large-scale structures, and that the absence of earlier detections of such structures was likely due to observational limitations," says Colin Norman of Johns Hopkins University in Baltimore, US, also a co-author on the study.

The galaxies now detected are some of the faintest that current telescopes can observe. This discovery required observations over several hours using the largest optical telescopes available, including ESO's VLT. Using the MUSE and FORS2 instruments on the VLT at ESO's Paranal Observatory in the Chilean Atacama Desert, the team confirmed the link between four of the six galaxies and the black hole. "We believe we have just seen the tip of the iceberg, and that the few galaxies discovered so far around this supermassive black hole are only the brightest ones," said co-author Barbara Balmaverde, an astronomer at INAF in Torino, Italy.

These results contribute to our understanding of how supermassive black holes and large cosmic structures formed and evolved. ESO's Extremely Large Telescope, currently under construction in Chile, will be able to build on this research by observing many more fainter galaxies around massive black holes in the early Universe using its powerful instruments.

Toliman

#2103
Death by Spaghettification: ESO Telescopes Record Last Moments of Star Devoured by a Black Hole
https://www.eso.org/public/news/eso2018/

Toliman


Toliman

NASA'S HUBBLE SEES UNEXPLAINED BRIGHTNESS FROM COLOSSAL EXPLOSION
https://hubblesite.org/contents/news-releases/2020/news-2020-48

NEUTRON-STAR COLLISION RELEASES PUZZLING BURST OF INFRARED LIGHT
In our infinite universe, stars can go bump in the night. When this happens between a pair of burned-out, crushed stars called neutron stars, the resulting fireworks show, called a kilonova, is beyond comprehension. The energy unleashed by the collision briefly glows 100 million times brighter than our Sun.

What's left from the smashup? Typically an even more crushed object called a black hole. But in this case Hubble found forensic clues to something even stranger happening after the head-on collision.

The intense flood of gamma-rays signaling astronomers to this event has been seen before in other stellar smashups. But something unexpected popped up in Hubble's near-infrared vision. Though a gusher of radiation from the aftermath of the explosion—stretching from X-rays to radio waves—seemed typical, the outpouring of infrared radiation was not. It was 10 times brighter than predicted for kilonovae. Without Hubble, the gamma-ray burst would have appeared like many others, and scientists would not have known about the bizarre infrared component.

The most plausible explanation is that the colliding neutron stars merged to form a more massive neutron star. It's like smashing two Volkswagen Beetles together and getting a limousine. This new beast sprouted a powerful magnetic field, making it a unique class of object called a magnetar. The magnetar deposited energy into the ejected material, causing it to glow even more brightly in infrared light than predicted. (If a magnetar flew within 100,000 miles of Earth, its intense magnetic field would erase the data on every credit card on our planet!)

Long ago and far across the universe, an enormous burst of gamma rays unleashed more energy in a half-second than the Sun will produce over its entire 10-billion-year lifetime. In May of 2020, light from the flash finally reached Earth and was first detected by NASA's Neil Gehrels Swift Observatory. Scientists quickly enlisted other telescopes — including NASA's Hubble Space Telescope, the Very Large Array radio observatory, the W. M. Keck Observatory, and the Las Cumbres Observatory Global Telescope network — to study the explosion's aftermath and the host galaxy. It was Hubble that provided the surprise.

Based on X-ray and radio observations from the other observatories, astronomers were baffled by what they saw with Hubble: the near-infrared emission was 10 times brighter than predicted. These results challenge conventional theories of what happens in the aftermath of a short gamma-ray burst. One possibility is that the observations might point to the birth of a massive, highly magnetized neutron star called a magnetar.

"These observations do not fit traditional explanations for short gamma-ray bursts," said study leader Wen-fai Fong of Northwestern University in Evanston, Illinois. "Given what we know about the radio and X-rays from this blast, it just doesn't match up. The near-infrared emission that we're finding with Hubble is way too bright. In terms of trying to fit the puzzle pieces of this gamma-ray burst together, one puzzle piece is not fitting correctly."

Without Hubble, the gamma-ray burst would have appeared like many others, and Fong and her team would not have known about the bizarre infrared behavior. "It's amazing to me that after 10 years of studying the same type of phenomenon, we can discover unprecedented behavior like this," said Fong. "It just reveals the diversity of explosions that the universe is capable of producing, which is very exciting."

Light Fantastic

The intense flashes of gamma rays from these bursts appear to come from jets of material that are moving extremely close to the speed of light. The jets do not contain a lot of mass — maybe a millionth of the mass of the Sun — but because they're moving so fast, they release a tremendous amount of energy across all wavelengths of light. This particular gamma-ray burst was one of the rare instances in which scientists were able to detect light across the entire electromagnetic spectrum.

"As the data were coming in, we were forming a picture of the mechanism that was producing the light we were seeing," said the study's co-investigator, Tanmoy Laskar of the University of Bath in the United Kingdom. "As we got the Hubble observations, we had to completely change our thought process, because the information that Hubble added made us realize that we had to discard our conventional thinking, and that there was a new phenomenon going on. Then we had to figure out what that meant for the physics behind these extremely energetic explosions."

Gamma-ray bursts — the most energetic, explosive events known — live fast and die hard. They are split into two classes based on the duration of their gamma rays.

If the gamma-ray emission is greater than two seconds, it's called a long gamma-ray burst. This event is known to result directly from the core collapse of a massive star. Scientists expect a supernova to accompany this longer type of burst.

If the gamma-ray emission lasts less than two seconds, it's considered a short burst. This is thought to be caused by the merger of two neutron stars, extremely dense objects about the mass of the Sun compressed into the volume of a city. A neutron star is so dense that on Earth, one teaspoonful would weigh a billion tons! A merger of two neutron stars is generally thought to produce a black hole.

Neutron star mergers are very rare but are extremely important because scientists think that they are one of the main sources of heavy elements in the universe, such as gold and uranium.

Accompanying a short gamma-ray burst, scientists expect to see a "kilonova" whose peak brightness typically reaches 1,000 times that of a classical nova. Kilonovae are an optical and infrared glow from the radioactive decay of heavy elements and are unique to the merger of two neutron stars, or the merger of a neutron star with a small black hole.

Magnetic Monster?

Fong and her team have discussed several possibilities to explain the unusual brightness that Hubble saw. While most short gamma-ray bursts probably result in a black hole, the two neutron stars that merged in this case may have combined to form a magnetar, a supermassive neutron star with a very powerful magnetic field.

"You basically have these magnetic field lines that are anchored to the star that are whipping around at about a thousand times a second, and this produces a magnetized wind," explained Laskar. "These spinning field lines extract the rotational energy of the neutron star formed in the merger, and deposit that energy into the ejecta from the blast, causing the material to glow even brighter."

If the extra brightness came from a magnetar that deposited energy into the kilonova material, then within a few years, the team expects the ejecta from the burst to produce light that shows up at radio wavelengths. Follow-up radio observations may ultimately prove that this was a magnetar, and this may explain the origin of such objects.

"With its amazing sensitivity at near-infrared wavelengths, Hubble really sealed the deal with this burst," explained Fong. "Amazingly, Hubble was able to take an image only three days after the burst. Through a series of later images, Hubble showed that a source faded in the aftermath of the explosion. This is as opposed to being a static source that remains unchanged. With these observations, we knew we had not only nabbed the source, but we had also discovered something extremely bright and very unusual. Hubble's angular resolution was also key in pinpointing the position of the burst and precisely measuring the light coming from the merger."

NASA's upcoming James Webb Space Telescope is particularly well-suited for this type of observation. "Webb will completely revolutionize the study of similar events," said Edo Berger of Harvard University in Cambridge, Massachusetts, and principal investigator of the Hubble program. "With its incredible infrared sensitivity, it will not only detect such emission at even larger distances, but it will also provide detailed spectroscopic information that will resolve the nature of the infrared emission."

The team's findings appear in an upcoming issue of The Astrophysical Journal.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.

Toliman

A Cosmic Amethyst in a Dying Star
https://www.technology.org/2020/11/13/a-cosmic-amethyst-in-a-dying-star-2/

On Earth, amethysts can form when gas bubbles in lava cool under the right conditions. In space, a dying star with a mass similar to the Sun is capable of producing a structure on par with the appeal of these beautiful gems.

As stars like the Sun run through their fuel, they cast off their outer layers and the core of the star shrinks. Using NASA's Chandra X-ray Observatory, astronomers have found a bubble of ultra-hot gas at the center of one of these expiring stars, a planetary nebula in our galaxy called IC 4593. At a distance of about 7,800 light years from Earth, IC 4593 is the most distant planetary nebula yet detected with Chandra.

This new image of IC 4593 has X-rays from Chandra in purple, invoking similarities to amethysts found in geodes around the globe. The bubble detected by Chandra is from gas that has been heated to over a million degrees. These high temperatures were likely generated by material that blew away from the shrunken core of the star and crashed into gas that had previously been ejected by the star.

This composite image also contains visible light data from the Hubble Space Telescope (pink and green). The pink regions in the Hubble image are the overlap of emission from cooler gas composed of a combination of nitrogen, oxygen, and hydrogen, while the green emission is mainly from nitrogen.

IC 4593 is what astronomers call a "planetary nebula," a deceptive-sounding name because this class of objects has nothing to do with planets. (The name was given about two centuries ago because they looked like the disk of a planet when viewed through a small telescope.) In fact, a planetary nebula is formed after the interior of a star with about the mass of the Sun contracts and its outer layers expand and cool. In the case of the Sun, its outer layers could extend as far as the orbit of Venus during its red giant phase several billion years in the future.

In addition to the hot gas, this study also finds evidence for point-like X-ray source at the center of IC 4593. This X-ray emission has higher energies than the bubble of hot gas. The point source could be from the star that discarded its outer layers to form the planetary nebula or it could be from a possible companion star in this system.

A paper describing these results appears in the April 2020 issue of the Monthly Notices of the Royal Astronomical Society and is available online. The authors are Jesús A. Toalá (Instituto de Radioastronomía y Astrofísica (IRyA) in Michoacan, Mexico); M. A. Guerrero (Instituto de Astrofísica de Andalucía in Granada, Spain); L. Bianchi (The Johns Hopkins University, in Baltimore, Maryland); Y.-H. Chu (Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA) in Taipei, Taiwan, Republic of China); and O. De Marco (Macquarie University, in Sydney, Australia).


Toliman

Potential Plumes on Europa Could Come From Water in the Crust
https://www.technology.org/2020/11/14/potential-plumes-on-europa-could-come-from-water-in-the-crust/

Scientists have theorized on the origin of the water plumes possibly erupting from Jupiter's moon Europa. Recent research adds a new potential source to the mix.

Plumes of water vapor that may be venting into space from Jupiter's moon Europa could come from within the icy crust itself, according to new research. A model outlines a process for brine, or salt-enriched water, moving around within the moon's shell and eventually forming pockets of water – even more concentrated with salt – that could erupt.

Europa scientists have considered the possible plumes on Europa a promising way to investigate the habitability of Jupiter's icy moon, especially since they offer the opportunity to be directly sampled by spacecraft flying through them. The insights into the activity and composition of the ice shell covering Europa's global, interior ocean can help determine if the ocean contains the ingredients needed to support life.

Vawmataw

Famed Arecibo telescope, on the brink of collapse, will be dismantled

The Arecibo telescope's long and productive life has come to an end. The National Science Foundation (NSF) announced today it will decommission the iconic radio telescope in Puerto Rico following two cable breaks in recent months that have brought the structure to near collapse. The 57-year-old observatory, a survivor of numerous hurricanes and earthquakes, is now in such a fragile state that attempting repairs would put staff and workers in danger. "This decision was not an easy one to make," Sean Jones, NSF's assistant director for mathematical and physical sciences, said at a news briefing today. "We understand how much Arecibo means to [the research] community and to Puerto Rico."

https://www.sciencemag.org/news/2020/11/famed-arecibo-telescope-brink-collapse-will-be-dismantled
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Toliman


Toliman

HUBBLE CATCHES POSSIBLE 'SHADOW PLAY' OF THE DISK AROUND A BLACK HOLE
https://hubblesite.org/contents/news-releases/2020/news-2020-58

BLACK HOLE'S DUST RING MAY BE CASTING SHADOWS FROM HEART OF A GALAXY
Black holes are the universe's monsters: voracious eating machines that swallow anything that ventures near them.

These compact behemoths pull stars and gas into a disk that swirls around them. The feeding generates a prodigious amount of energy, producing a powerful gusher of light from superheated infalling gas.

These disks are so far away that it's nearly impossible to discern any detail about them. But by a quirk of alignment, astronomers may be getting a glimpse of the structure of the disk around the black hole in nearby galaxy IC 5063. The Hubble Space Telescope has observed a collection of narrow bright rays and dark shadows beaming out of the blazingly bright center of the active galaxy.

One possible explanation for the effect is that the dusty disk of material surrounding the black hole is casting its shadow into space. Some light penetrates gaps in the dust ring, creating the bright rays that resemble the floodlights accompanying a Hollywood movie premier. These telltale beams offer clues to the distribution of material near the black hole that is causing the shadow play.

What is fascinating is that we can see the same interplay of light and shadow in our sky at sunset, when the setting Sun casts streaks of bright rays and dark shadows through scattered clouds.

More here:
https://hubblesite.org/contents/news-releases/2020/news-2020-58



Toliman

Almost like on Venus
https://www.technology.org/2020/11/26/almost-like-on-venus/

A team of international scientists led by ETH researcher Paolo Sossi has gained new insights into Earth's atmosphere of 4.5 billion years ago. Their results have implications for the possible origins of life on Earth.

Four-​and-a-half billion years ago, Earth would have been hard to recognise. Instead of the forests, mountains and oceans that we know today, the surface of our planet was covered entirely by magma – the molten rocky material that emerges when volcanoes erupt. This much the scientific community agrees on. What is less clear is what the atmosphere at the time was like. New international research efforts led by Paolo Sossi, senior research fellow at ETH Zurich and the NCCR PlanetS, attempt to lift some of the mysteries of Earth's primeval atmosphere. The findings were published in the journal Science Advances.

Toliman

Astronomical instrument hunts for ancient metal
https://www.technology.org/2020/11/26/astronomical-instrument-hunts-for-ancient-metal/

Researchers created a new astronomical instrument that has successfully aided in estimating the abundance of metals in the early universe. The WINERED instrument allows for better observations of astronomical bodies like quasars in the early universe, billions of years ago.

Researchers hope this deeper level of exploration could help answer questions about the origins not only of metals in the universe but also of the stars themselves.

Iron is one of the most important elements for life as we know it, and for the technology, both primitive and modern, that has shaped human history. But details of the exact origin of iron and other important metals such as magnesium remain elusive. Exploration of this is important in the field of astronomy as it also connected to the origins of the first stars that would have begun to shine several hundred million years after the Big Bang.

Project Research Associate Hiroaki Sameshima from the Institute of Astronomy at the University of Tokyo and his team decided a new instrument was needed to study these matters. Due to limited instrumentation, previous observations to collect data for the study of metals' origins mainly looked at old stars nearby. But this only gave astronomers information about our own unique galaxy. A new instrument with enhanced sensitivity to near-infrared light could push the boundary and open up observations of distant quasars, ferociously energetic ancient galactic cores that emitted light when the universe was only 2.4 billion years old.

"By mounting the WINERED instrument on a large telescope, we can see further back in time as we can observe bodies more distant, or more ancient, than those from previous studies. We can now see details of quasars over 10 billion years old," said Sameshima. "WINERED is a special kind of spectrograph, which can read the chemical signatures present in the light from distant bodies. It revealed to us the fingerprints of iron and magnesium in the light from these quasars, and this allowed us to calculate the abundance of these elements when the universe was much younger than previous studies allowed."

Now that the researchers have established a new method to directly examine the abundance of metals in the early universe, the challenge becomes one of refining the technique and broadening its scope to collect more data. With improved data, astronomers can build on this study and create theories to explain the origins of metals including the iron in your blood.

Toliman

What is Lunar Flashlight?
https://www.technology.org/2020/11/29/what-is-lunar-flashlight/

Ahead of Artemis astronauts landing on the Moon in 2024, a small spacecraft called Lunar Flashlight will fly as a secondary payload aboard NASA's Artemis I mission.

One of several precursor missions to the Moon, Lunar Flashlight will use lasers to help determine the presence and nature of water ice at the bottom of some of the Moon's craters. The availability of water is an essential local resource for future crews to use for drinking water and fuel.

Toliman

Quote from: Vawmataw on November 19, 2020, 04:35:40 PM
Famed Arecibo telescope, on the brink of collapse, will be dismantled

The Arecibo telescope's long and productive life has come to an end. The National Science Foundation (NSF) announced today it will decommission the iconic radio telescope in Puerto Rico following two cable breaks in recent months that have brought the structure to near collapse. The 57-year-old observatory, a survivor of numerous hurricanes and earthquakes, is now in such a fragile state that attempting repairs would put staff and workers in danger. "This decision was not an easy one to make," Sean Jones, NSF's assistant director for mathematical and physical sciences, said at a news briefing today. "We understand how much Arecibo means to [the research] community and to Puerto Rico."

https://www.sciencemag.org/news/2020/11/famed-arecibo-telescope-brink-collapse-will-be-dismantled

And today it definitelly collapsed :(

Arecibo Observatory collapses ahead of planned demolition
https://edition.cnn.com/2020/12/01/world/arecibo-observatory-collapse-scn-trnd/index.html

The instrument platform of the 305-meter telescope at Arecibo Observatory in Puerto Rico collapsed overnight, according to the National Science Foundation.

It's a final blow to one of the most powerful telescopes on Earth that has aided astronomical discoveries for 57 years and withstood hurricanes, earthquakes and tropical storms.
The collapse occurred just weeks after NSF announced that the telescope would be decommissioned and disassembled through a controlled demolition after sustaining irreparable damage earlier this year.
"The instrument platform of the 305m telescope at Arecibo Observatory in Puerto Rico fell overnight. No injuries were reported. NSF is working with stakeholders to assess the situation. Our top priority is maintaining safety. NSF will release more details when they are confirmed," according to a tweet by the National Science Foundation.


https://twitter.com/universetoday/status/1333816650970390528/photo/1


wm.annis

Quote from: Toliman on December 01, 2020, 12:03:18 PM
And today it definitelly collapsed :(

Keftxo!

They were going to bring it down anyway, but still.

Toliman


Vawmataw

Time to recalculate the galactic year hrh
Fmawn Ta 'Rrta - News IN NA'VI ONLY (Discord)
Traducteur francophone de Kelutral.org, dict-navi et Reykunyu

Toliman


Toliman

HUBBLE CAPTURES UNPRECEDENTED FADING OF STINGRAY NEBULA
https://hubblesite.org/contents/news-releases/2020/news-2020-55

IMAGES SPANNING 20 YEARS REVEAL DISAPPEARING NEBULA
Great things take time. This is true when it comes to many processes in the universe. For example, it takes millions of years for stars—the building blocks of the universe—to form. Then, many stars last for billions of years before they die and begin to eject shells of gas that glow against the vastness of space—what we call nebulas. It can be exceedingly rare to capture some of these processes in real time.

Lucky for us, it seems as if the Stingray nebula, Hen 3-1357, was destined to stand out from the crowd since its beginnings. It was dubbed the youngest known planetary nebula in 1998 after Hubble caught a rare peek at the central star's final stages of life. Now, twenty years after its first snapshot, the Stingray nebula is capturing the attention of astronomers again for a very different reason.

Images from 2016 show a nebula that has drastically faded over the last two decades. Additionally, shells of gas that surrounded the central star have changed, no longer as crisp as they once were. Changes like this have never been captured at this clarity before.

Astronomers have caught a rare look at a rapidly fading shroud of gas around an aging star. Archival data from NASA's Hubble Space Telescope reveal that the nebula Hen 3-1357, nicknamed the Stingray nebula, has faded precipitously over just the past two decades. Witnessing such a swift rate of change in a planetary nebula is exceeding rare, say researchers.

Images captured by Hubble in 2016, when compared to Hubble images taken in 1996, show a nebula that has drastically dimmed in brightness and changed shape. Bright blue fluorescent tendrils and filaments of gas toward the center of the nebula have all but disappeared, and the wavy edges that earned this nebula its aquatic-themed name are virtually gone. The young nebula no longer pops against the black velvet background of the vast universe.

"This is very, very dramatic, and very weird," said team member Martín A. Guerrero of the Instituto de Astrofísica de Andalucía in Granada, Spain. "What we're witnessing is a nebula's evolution in real-time. In a span of years, we see variations in the nebula. We have not seen that before with the clarity we get with this view."