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Researchers Now Say That Black Holes May Form without Collapsing Stars

Source: Interesting Engineering

Supermassive Black Holes (SMBHs) have, until now, traditionally been believed to only form after
the explosion or collapse of a star.

The gravitational force of a star collapsing in on itself at the end of its lifespan — after a hypernova explosion — creates a black hole.

These, in theory, become Supermassive Black Holes by sucking in surrounding matter until they grow to an enormous size.

There is one big problem with this theory, but new research by researchers at Western University in Ontario, Canada, may provide us with an answer.

The problem

The outward pressure of a star’s nuclear fusion is what prevents it from collapsing under the gravitational force created by its own mass. When the energy dissipates, the star collapses in on
itself. Then, a black hole forms and becomes larger by ‘feeding’ on its surroundings.

This takes a very long time — Supermassive Black Holes form over the course of millennia.

The problem is that scientists have observed SMBHs that are too old to have had enough time after the Big Bang, and gradually form into the space giants that they became.

For example, one SMBH was discovered by astronomers in 2017 that was much too large, especially to have been so large 690 million years after the Big Bang.

New research findings

Two researchers at Western University in Ontario, Canada, believe they might have an answer. Their new theory, called ‘direct collapse,’ attempts to provide an explanation for these ancient SMBHs.

The authors are Shantanu Basu and Arpan Das. Basu writes that SMBHs were able to form very quickly in the early universe before the growth was halted by the radiation of forming stars.

In direct-collapse black holes, Universe Today reports, the Eddington Limit regulates mass growth. Ancient black holes could exceed that limit slightly, the researchers say. They call this ‘super-Eddington accretion.’

“Supermassive black holes only had a short time period where they were able to grow fast and then at some point, because of all the radiation in the universe created by other black holes and stars, their production came to a halt,” Basu explained in a press release published on Eurekalert.org.

“That’s the direct-collapse scenario.”

“This is indirect observational evidence that black holes originate from direct-collapses and not from stellar remnants,” Basu continued, putting a spanner in the works for a long-held belief in the
scientific community on the formation of black holes.

Their findings are published in a paper, called ‘The Mass Function of Supermassive Black Holes in the Direct-collapse Scenario,’ found in The Astrophysical Journal Letters.

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Space

The Interstellar Research Initiative plans to send people to the exoplanet of Proxima Centauri b

In an attempt to protect humanity from extinction in the event of some kind of global catastrophe of a planetary scale, a group of scientists announced a bold plan for the colonization of a distant exoplanet.

Proxima Centauri b

Scientists from the Initiative for Interstellar Studies said they were considering sending people to a potentially inhabited exoplanet in another stellar system.

The most promising option they consider, Proxima Centauri b, which is 4.24 light years away from Earth, which means the journey will take centuries or even millennia. This suggests that generations will succeed each other during the journey.

Technically, this is possible.

However, the challenges facing the mission are so numerous and complex that it can take decades to prepare.

“From the point of view of physics, there are no fundamental obstacles. There are many nuances, but this is not a violation of the fundamental laws of physics, ”said Andreas Hein, Executive Director of Initiative for Interstellar Studies.

No problem.

The main problem is the lack of experience being far beyond the Earth for such a period of time.

Even a flight to Mars, which will last about 6-8 months, raises a lot of questions.

Proxima Centauri b

There is no reliable protection against merciless radiation yet. Medical problems caused by a prolonged stay in space are still poorly understood. Other than that, there is no guarantee that Proxima Centauri b is indeed liveable.

Can you imagine what a setup would be if people born on a spaceship for one purpose would come to a planet absolutely unsuitable for settlement …

However, the authors of the project do not plan to curtail the program and continue to work actively in this direction.

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European Space Agency to launch space waste collector

A four-armed robotic junk collector will be launched into space by the European Space Agency in what it says will be the first mission to remove an item of debris from orbit.

European Space Agency to launch space waste collector

The ClearSpace-1 mission, scheduled for launch in 2025, will cost €120m and will grab a single piece of junk. But the agency hopes the mission will pave the way for a wide-reaching clear-up operation, with Esa’s director general calling for new rules that would compel those who launch satellites to take responsibility for removing them from orbit once they are retired from use.

Jan Wörner, CEO of ESA, said:

Imagine how dangerous sailing the high seas would be if all the ships ever lost in history were still drifting on top of the water. That is the current situation in orbit, and it cannot be allowed to continue.

In the past 60 years, thousands of tonnes of junk has accumulated around the Earth, including old rocket parts, about 3,500 defunct satellites and an estimated 750,000 smaller fragments, some from collisions between larger bits of junk. The fragments are typically circulating with a velocity of 20,000km/h (12,500mph).

Unless a clear-up operation is mounted, the chances of collisions will escalate as thousands more satellites are put into orbit.

Funding for the mission was agreed at Space19+, ESA’s misterial council, which took place in Seville, Spain, at the end of November. The mission will be run by a consortium led by a Swiss startup called Clearspace.

The target for ClearSpace-1 is a piece of junk called Vespa, which was left in an orbit around 800km above the Earth by ESA’s Vega launcher in 2013. Vespa weighs 100kg – around the size of a small satellite – and was selected because it has a simple shape and sturdy construction, which make it unlikely to fragment when it is grabbed.

The “chaser” ClearSpace space probe will be launched into the target orbit where it will track down Vespa, grab it using a quartet of robotic arms and drag it out of orbit, with Vespa and the chaser both burning up in the atmosphere on the way down to Earth.

A future ambition is to create a clear-up robot that could eject junk into the atmosphere, before continuing to capture and de-orbit other pieces of junk.

Source

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Asteroid as big as the pyramids on its way and could zoom past Earth on Friday

An asteroid as big as the Egyptian pyramids is zooming towards Earth and will squeeze past us on Friday – if it doesn’t smash on to our home planet’s surface.

Named 2019 WR3, NASA expects the space rock to make a “close approach” to Earth later this week.

The space agency has classified the asteroid as a “near-Earth object (NEO)” which means its orbit brings it very close – in cosmic terms – to Earth.

The asteroid was first spotted late last week.

NASA has now observed the asteroid some 74 times to better get a sense of its size and trajectory.

WR3 is believed to have a diameter of between 76m to 170m.

It is expected that on December 6, the asteroid will pass within 5.44 million km of Earth at speeds of 27,036 km/hr.

The warning comes as the European Space Agency approves a $471 million mission called Hera to examine whether a rogue asteroid on its way to Earth could be deflected out of the way.

Working with NASA, the ESA will send a pair of spacecraft to a double-asteroid system called Didymos to examine the asteroids and send valuable data back home.

The larger asteroid Didymoon is about 800m across, orbited by a moon about 160m wide.

If an asteroid the size of Didymoon were to hammer into Earth, it would be devastating.

Patrick Michel, ESA’s lead scientist for Hera, said it was vital to keep an eye on it so we can take action if needed.

“The probability is low but the consequences are high,” Michel told Space.com.

“This is why it’s relevant to take care of it. Moreover, we have the tools … We can’t lose more time.”

The Hera spacecraft will launch in 2024.

Meanwhile, Queens University Belfast professor Alan Fitzsimmons has called for amateur astronomers to assist the Hera mission’s broader goal of protecting Earth against asteroids by nominating asteroids to watch.

“We will get a serious asteroid impact sometime,” he told the BBC.

“It may not be in our lifetime, but mother nature controls when that will happen.

‘We will get a serious asteroid impact sometime.’

“We will need to do something about it. We’ll need to move that asteroid so it misses us and doesn’t hit us.

“Asteroid research is one area of astronomy where amateur observes continue to make an essential contribution,” he said.

Source 7news.com.au

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