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Cosmic Legos: Black holes merge into never-before-seen size



Black holes are getting stranger – even to astronomers. They’ve now detected the signal from a long ago violent collision of two black holes that created a new one of a size that had never been seen before.

“It’s the biggest bang since the Big Bang observed by humanity,” said Caltech physicist Alan Weinstein, who was part of the discovery team.

Black holes are compact regions of space so densely packed that not even light can escape. Until now, astronomers only had observed them in two general sizes. There are “small” ones called stellar black holes that are formed when a star collapses and are about the size of small cities. And there are supermassive black holes that are millions, maybe billions, of times more massive than our sun and around which entire galaxies revolve.

According to astronomers’ calculations, anything in between didn’t quite make sense, because stars that grew too big before collapse would essentially consume themselves, leaving no black holes.

Star collapses couldn’t create stellar black holes much bigger than 70 times the mass of our sun, scientists thought, according to physicist Nelson Christensen, research director of the French National Centre for Scientific Research.

Then in May 2019 two detectors picked up a signal that turned out to be the energy from two stellar black holes – each large for a stellar black hole – crashing into each other. One was 66 times the mass of our sun and the other a husky 85 times the mass of the sun.

The end result: The first ever discovered intermediate black hole, at 142 times the mass of the sun.

Lost in the collision was an enormous amount of energy in the form of a gravitational wave, a ripple in space that travels at the speed of light. It was that wave that physicists in the United States and Europe, using detectors called LIGO and Virgo, captured last year. After deciphering the signal and checking their work, scientists published the results Wednesday in Physical Review Letters and Astrophysical Journal Letters.

Because the detectors allow scientists to pick up the gravitational waves as audio signals, scientists actually heard the collision. For all the violence and drama, the signal lasted only one-tenth of a second.

“It just sounds like a thud,” Weinstein said. “It really doesn’t sound like much on a speaker.”

This crash happened about seven billion years ago, when the universe was about half its current age, but is only being detected now because it is incredibly far away.

Black hole collisions have been observed before, but the black holes involved were smaller to begin with and even after the merger didn’t grow beyond the size of typical stellar black holes.

Scientists still don’t know how supermassive black holes at the center of galaxies formed, Christensen said, but this new discovery may offer a clue.

Perhaps, like playing Legos, smaller blocks combine to make bigger ones and those combine to make even bigger ones, said Harvard astronomer Avi Loeb, who wasn’t part of the study but said the results chart new astronomical territory.

And indeed the bigger of the two black holes involved in this crash could have been the result of an earlier merger, both Weinstein and Christensen said, further bolstering that theory.

“It’s conceivable that this pair of black holes formed entirely differently, possibly in a dense system with lots of dead stars whizzing about, which allows one black hole to capture another during a fly by,” said Barnard College astronomer Janna Levin, who wasn’t part of the research and is author of the book “Black Hole Survival Guide.”

On the other hand, scientists can’t quite explain how merged black holes, flying around the universe, would meet so many others to merge again and grow ever bigger. It could instead be that supermassive black holes were formed in the immediate aftermath of the Big Bang.

“In astrophysics we’re always faced with surprises,” Weinstein said.

(Cover photo: This illustration provided by LIGO/Caltech in September 2020 depicts two black holes of about 66 and 85 solar masses spiraling into each other to form the GW190521 black hole. Gravitational waves from the merger were detected by the LIGO and Virgo observatories in May 2019. /AP )

Source(s): AP

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Air leaking from International Space Station but no danger to crew: Roscosmos agency – Reuters Canada



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MOSCOW (Reuters) – The International Space Station is leaking air in above-normal volumes, but the leak presents no danger to the Russian-American crew, the Russian space agency Roscosmos said on Tuesday.

The leak has been localised to one section of a service module and the crew, made up of U.S. astronaut Chris Cassidy and Russian cosmonauts Anatoly Ivanishin and Ivan Vagner, plan to eliminate it in the coming days, Russia’s RIA news agency quoted Roscosmos executive director Sergei Krikalev as saying.

Roscosmos said additional air may be delivered to the station.

Reporting by Polina Devitt; Writing by Olzhas Auyezov; Editing by Kevin Liffey

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Rare blue moon will bring a Halloween 2020 treat to the skies – CNET



A brilliant full moon rises at NASA’s Kennedy Space Center in Florida in 2017.

NASA/Kim Shiflett

Another highly unusual event is headed our way in this bizarre year. The 2020 Halloween full moon will be visible to the entire world, rather than just parts of it, for the first time since World War II, astronomy educator and former planetarium director Jeffrey Hunt says. 

“When I was teaching, my high school students thought a full moon occurred every Halloween,” Hunt told me. Not quite, though pop culture decorations sure make it seem that way. The last Halloween full moon visible around the globe came in 1944, he said. He’s written about the event on his web site, When the Curves Line Up. There was a Halloween full moon for some locations in 1955, but that didn’t include western North America and the western Pacific, Hunt says.

While this year’s Halloween full moon will be visible in all parts of the globe, that doesn’t mean every single citizen will have a view. Residents across both North America and South America will see it, as will India, all of Europe and much of Asia. But while Western Australians will see it, those in the central and eastern parts of the country will not. 

Know time zones well? “Every time zone has it except those east of (GMT) +8 time zones if they have daylight time, or (GMT) +9 with no daylight time,” Hunt says.

Want to see the Halloween full moon? It’s so bright at the full phase it doesn’t matter if you’re in a crowded city or out on the farm. And you don’t need pricey equipment.

“Walk outside, and take a look,” Hunt says. 

Don’t be surprised, though, if you snap a Halloween moon shot with your phone and the photo doesn’t match what you saw.

“When the moon is photographed with a smartphone the results can be disappointing,” Hunt admits. “A telephoto attachment will help make the moon larger.  Be sure to check that the adapter fits on your make and model.  Also don’t overexpose the moon. Adjust the camera’s brightness so that features are visible and not blotted out by the moon’s brightness.” 

If you’re determined to get a good shot, Oct. 1 brings a full moon, so there’s time to practice. Because that makes two full moons in the same month, the Halloween full moon could also be known as a “blue moon.”

If you’re too busy watching horror movies (or doing whatever the coronavirus equivalent of trick-or-treating is), you’ll have to wait until 2039 for another global full moon.

“Of course, full moons occur in October during the intervening years, just not on Halloween,” Hunt says. And a Halloween full moon may appear in your region before then. It just won’t be seen around the world.

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‘Earthgrazer’ meteor filmed skimming Earth’s atmosphere and bouncing into space – Yahoo Canada Sports



The earthgrazer streaked across the sky above Germany (ESA)
The earthgrazer streaked across the sky above Germany (ESA)
<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="Cameras on Earth captured a rare sight, an ‘earthgrazer’, a meteoroid which skims Earth’s atmosphere before ‘bouncing’ back into space.&nbsp;” data-reactid=”23″>Cameras on Earth captured a rare sight, an ‘earthgrazer’, a meteoroid which skims Earth’s atmosphere before ‘bouncing’ back into space. 

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="This particular meteoroid got hair raisingly close, flying as low as 56 miles up, far below any orbiting satellites, before bouncing back out.” data-reactid=”24″>This particular meteoroid got hair raisingly close, flying as low as 56 miles up, far below any orbiting satellites, before bouncing back out.

The space rock whizzed through the night sky above Northern Germany and the Netherlands in the early hours of 22 September. 

A meteoroid is typically a fragment of a comet or asteroid that becomes a meteor (a bright light streaking through the sky) when it enters the atmosphere. 

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="Read more: There might once have been life on the moon

Most of them disintegrate, possibly with pieces reaching the ground as meteorites.&nbsp;” data-reactid=”29″>Read more: There might once have been life on the moon

Most of them disintegrate, possibly with pieces reaching the ground as meteorites. 

Earthgrazers are a bit luckier, and don’t burn up, but bounce back out, only grazing the edges of our planet’s protective gassy shield.

Earthgrazers don’t happen very often, just a handful of times per year.

It was spotted by cameras in the Global Meteor Network, a project which aims to cover the globe with meteor cameras and provide the public with real time alerts, building a picture of the meteoroid environment around Earth.

“The network is basically a decentralised scientific instrument, made up of amateur astronomers and citizen scientists around the planet each with their own camera systems” explains Denis Vida, who founded it.

<p class="canvas-atom canvas-text Mb(1.0em) Mb(0)–sm Mt(0.8em)–sm" type="text" content="Read more: Exoplanet twice the size of Earth ‘could be habitable’” data-reactid=”34″>Read more: Exoplanet twice the size of Earth ‘could be habitable’

“We make all data such as meteoroid trajectories and orbits available to the public and scientific community, with the goal of observing rare meteor shower outbursts and increasing the number of observed meteorite falls and helping to understand delivery mechanisms of meteorites to Earth”.

Tens of thousands of meteorites have been found on Earth, yet, of these only about 40 can be traced back to a parent asteroid or asteroidal source.

By better understanding these small bodies we are able to build up a more complete image of the Solar System, including potentially dangerous asteroids, meteor shower outbursts which could endanger satellites, as well as the chemistry and origins of our Solar System itself.

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