Long Lost Asteroid is Rediscovered Just Before Making a Close Pass by Earth
(outerplaces.com) - - Asteroid 2010 WC9 was first detected way back on November 30, 2010 by the Catalina Sky Survey at the University of Arizona, who ended up losing track of it a couple weeks later. Eight years later, we found it again.
WC9 was finally rediscovered last week on May 8, 2018, being given a temporary name until astronomers realized that they'd seen this giant rock before. And while there's no danger of it hitting Earth, part of the reason it was so easily spotted is because it's coming within 0.53 lunar-distances from the planet, which means it will be passing midway between the Earth and Moon this coming Tuesday, May 15, according to EarthSky.
Although it will be passing at a distance of 126,419 miles (203,453 kilometers), it will be visible with even a small telescope. Mostly because it's large: estimates on the size of WC9 range from 197 to 427 feet (60 to 130 meters), and it's extremely rare for asteroids that big to make such a close encounter with Earth (although it's not a large asteroid in general).
If you want to see the asteroid as it's going by, you can either attempt to see it yourself if you have the right equipment - again, your naked eye won't cut it - or you can check out a live broadcast from Northolt Branch Observatories in London. Its approach will begin at 6:05 p.m. Eastern time, and the window of time to see it as it flies past will be about 25 minutes.
While this asteroid will be extremely large and incredible close by our standards, it's far from the first time that big asteroids have brushed past the planet, and there's nothing to worry about. This year alone, we've had plenty of other asteroids come "hazardously" close to Earth, and we're still here, aren't we?
And if WC9 had to pass in between Earth and the Moon before we could find it again, then that's fine - better that we know where an asteroid is than not, just in case.
Source
Could A Multiverse Be Hospitable To Life?
(phys.org) - - A Multiverse—where our Universe is only one of many—might not be as inhospitable to life as previously thought, according to new research.
Questions about whether other universes might exist as part of a larger Multiverse, and if they could harbour life, are burning issues in modern cosmology.
Now new research led by Durham University, UK, and Australia's University of Sydney, Western Sydney University and the University of Western Australia, has shown that life could potentially be common throughout the Multiverse, if it exists.
The key to this, the researchers say, is dark energy, a mysterious "force" that is accelerating the expansion of the Universe.
Scientists say that current theories of the origin of the Universe predict much more dark energy in our Universe than is observed. Adding larger amounts would cause such a rapid expansion that it would dilute matter before any stars, planets or life could form.
The Multiverse theory, introduced in the 1980s, can explain the "luckily small" amount of dark energy in our Universe that enabled it to host life, among many universes that could not.
Using huge computer simulations of the cosmos, the new research has found that adding dark energy, up to a few hundred times the amount observed in our Universe, would actually have a modest impact upon star and planet formation.
This opens up the prospect that life could be possible throughout a wider range of other universes, if they exist, the researchers said.
The findings are to be published in two related papers in the journal Monthly Notices of the Royal Astronomical Society.
The simulations were produced under the EAGLE (Evolution and Assembly of GaLaxies and their Environments) project—one of the most realistic simulations of the observed Universe.
Jaime Salcido, a postgraduate student in Durham University's Institute for Computational Cosmology, said: "For many physicists, the unexplained but seemingly special amount of dark energy in our Universe is a frustrating puzzle.
"Our simulations show that even if there was much more dark energy or even very little in the Universe then it would only have a minimal effect on star and planet formation, raising the prospect that life could exist throughout the Multiverse."
Dr. Luke Barnes, a John Templeton Research Fellow at Western Sydney University, said: "The Multiverse was previously thought to explain the observed value of dark energy as a lottery—we have a lucky ticket and live in the Universe that forms beautiful galaxies which permit life as we know it.
"Our work shows that our ticket seems a little too lucky, so to speak. It's more special than it needs to be for life. This is a problem for the Multiverse; a puzzle remains."
The videos shows a time lapse of the simulated universe, from the initial condition -- equivalent of the initial density fluctuation of the cosmic microwave background (CMB), and through 13.7 billion years to what it would become today.
Dr. Pascal Elahi, Research Fellow at the University of Western Australia, said: "We asked ourselves how much dark energy can there be before life is impossible? Our simulations showed that the accelerated expansion driven by dark energy has hardly any impact on the birth of stars, and hence places for life to arise. Even increasing dark energy many hundreds of times might not be enough to make a dead universe."
The researchers said their results were unexpected and could be problematic as they cast doubt on the ability of the theory of a Multiverse to explain the observed value of dark energy.
According to the research, if we live in a Multiverse, we'd expect to observe much more dark energy than we do—perhaps 50 times more than we see in our Universe.
Although the results do not rule out the Multiverse, it seems that the tiny amount of dark energy in our Universe would be better explained by an, as yet, undiscovered law of nature.
Professor Richard Bower, in Durham University's Institute for Computational Cosmology, said: "The formation of stars in a universe is a battle between the attraction of gravity, and the repulsion of dark energy.
"We have found in our simulations that universes with much more dark energy than ours can happily form stars. So why such a paltry amount of dark energy in our Universe?
"I think we should be looking for a new law of physics to explain this strange property of our Universe, and the Multiverse theory does little to rescue physicists' discomfort."
Source
(outerplaces.com) - - Asteroid 2010 WC9 was first detected way back on November 30, 2010 by the Catalina Sky Survey at the University of Arizona, who ended up losing track of it a couple weeks later. Eight years later, we found it again.
WC9 was finally rediscovered last week on May 8, 2018, being given a temporary name until astronomers realized that they'd seen this giant rock before. And while there's no danger of it hitting Earth, part of the reason it was so easily spotted is because it's coming within 0.53 lunar-distances from the planet, which means it will be passing midway between the Earth and Moon this coming Tuesday, May 15, according to EarthSky.
Although it will be passing at a distance of 126,419 miles (203,453 kilometers), it will be visible with even a small telescope. Mostly because it's large: estimates on the size of WC9 range from 197 to 427 feet (60 to 130 meters), and it's extremely rare for asteroids that big to make such a close encounter with Earth (although it's not a large asteroid in general).
If you want to see the asteroid as it's going by, you can either attempt to see it yourself if you have the right equipment - again, your naked eye won't cut it - or you can check out a live broadcast from Northolt Branch Observatories in London. Its approach will begin at 6:05 p.m. Eastern time, and the window of time to see it as it flies past will be about 25 minutes.
While this asteroid will be extremely large and incredible close by our standards, it's far from the first time that big asteroids have brushed past the planet, and there's nothing to worry about. This year alone, we've had plenty of other asteroids come "hazardously" close to Earth, and we're still here, aren't we?
And if WC9 had to pass in between Earth and the Moon before we could find it again, then that's fine - better that we know where an asteroid is than not, just in case.
Source
Could A Multiverse Be Hospitable To Life?
Artistic impression of a Multiverse -- where our Universe is only one of many. According to the research varying amounts of dark energy have little effect on star formation. This raises the prospect of life in other universes -- if the Multiverse exists. Credit: Jaime Salcido/simulations by the EAGLE Collaboration
(phys.org) - - A Multiverse—where our Universe is only one of many—might not be as inhospitable to life as previously thought, according to new research.
Questions about whether other universes might exist as part of a larger Multiverse, and if they could harbour life, are burning issues in modern cosmology.
Now new research led by Durham University, UK, and Australia's University of Sydney, Western Sydney University and the University of Western Australia, has shown that life could potentially be common throughout the Multiverse, if it exists.
The key to this, the researchers say, is dark energy, a mysterious "force" that is accelerating the expansion of the Universe.
Scientists say that current theories of the origin of the Universe predict much more dark energy in our Universe than is observed. Adding larger amounts would cause such a rapid expansion that it would dilute matter before any stars, planets or life could form.
The Multiverse theory, introduced in the 1980s, can explain the "luckily small" amount of dark energy in our Universe that enabled it to host life, among many universes that could not.
Using huge computer simulations of the cosmos, the new research has found that adding dark energy, up to a few hundred times the amount observed in our Universe, would actually have a modest impact upon star and planet formation.
Image credit: Volker Springel and the Max-Planck-Institute for Astrophysics.
This opens up the prospect that life could be possible throughout a wider range of other universes, if they exist, the researchers said.
The findings are to be published in two related papers in the journal Monthly Notices of the Royal Astronomical Society.
The simulations were produced under the EAGLE (Evolution and Assembly of GaLaxies and their Environments) project—one of the most realistic simulations of the observed Universe.
Jaime Salcido, a postgraduate student in Durham University's Institute for Computational Cosmology, said: "For many physicists, the unexplained but seemingly special amount of dark energy in our Universe is a frustrating puzzle.
"Our simulations show that even if there was much more dark energy or even very little in the Universe then it would only have a minimal effect on star and planet formation, raising the prospect that life could exist throughout the Multiverse."
Dr. Luke Barnes, a John Templeton Research Fellow at Western Sydney University, said: "The Multiverse was previously thought to explain the observed value of dark energy as a lottery—we have a lucky ticket and live in the Universe that forms beautiful galaxies which permit life as we know it.
"Our work shows that our ticket seems a little too lucky, so to speak. It's more special than it needs to be for life. This is a problem for the Multiverse; a puzzle remains."
Dr. Pascal Elahi, Research Fellow at the University of Western Australia, said: "We asked ourselves how much dark energy can there be before life is impossible? Our simulations showed that the accelerated expansion driven by dark energy has hardly any impact on the birth of stars, and hence places for life to arise. Even increasing dark energy many hundreds of times might not be enough to make a dead universe."
The researchers said their results were unexpected and could be problematic as they cast doubt on the ability of the theory of a Multiverse to explain the observed value of dark energy.
According to the research, if we live in a Multiverse, we'd expect to observe much more dark energy than we do—perhaps 50 times more than we see in our Universe.
Although the results do not rule out the Multiverse, it seems that the tiny amount of dark energy in our Universe would be better explained by an, as yet, undiscovered law of nature.
Professor Richard Bower, in Durham University's Institute for Computational Cosmology, said: "The formation of stars in a universe is a battle between the attraction of gravity, and the repulsion of dark energy.
"We have found in our simulations that universes with much more dark energy than ours can happily form stars. So why such a paltry amount of dark energy in our Universe?
"I think we should be looking for a new law of physics to explain this strange property of our Universe, and the Multiverse theory does little to rescue physicists' discomfort."
Source
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