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Asteroid warning: NASA tracks a 'hazardous' asteroid barreling past Earth on Christmas – Express.co.uk

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An asteroid at the upper boundary of that estimate is comparable in height to Chicago’s Sears Tower.

But even at the lower end of the estimate, the imposing space rock is large enough to threaten millions of innocent lives.

NASA said: “Potentially hazardous asteroids are about 150 meters – almost 500ft – or larger, roughly twice as big as the Statue of Liberty is tall.

“They approach Earth’s orbit to within 7.5 million kilometres – about 4.6 million miles.

“By comparison, when Mars and Earth are at their closest, they are about 53 million kilometres – about 33 million miles – apart.”

“Potentially hazardous comets also get unusually close to Earth.”

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There's a comet up there! – The Bay Observer – Providing a Fresh Perspective for Hamilton and Burlington

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A bright comet is now in the evening sky and you can see it without a telescope. Comet F3 (NEOWISE) has been a fantastic object in the early morning pre-dawn sky but will be well placed below the Big Dipper to see and photograph over the next couple of weeks and hopefully into August. I have been following and imaging this comet since the first week of July and could see it even without binoculars (naked eye).

The comet was discovered on March 27, 2020, by the NEOWISE space telescope as it looks for near-earth objects that could potentially impact our planet. Measuring a little more than half the height of Mount Everest, this object falls into the category of a “once in a decade comet”.

Every year astronomers both amateur and professional observe 5 to 10 comets with telescopes. In most cases, they show a green nucleus from the sublimation of frozen chemicals such as ammonia and others. The extremely faint tail is seen when photographed but all comets are different in composition and appearance as Neowise does not appear green. The last bright comet that was visible to the naked eye for the whole world to see was Comet Hale-Bopp in 1997. And like Neowise, it too had a blue ion or gas tail and a fan-shaped dust tail created when comets round the sun as this one did on July 3 at a close distance of 43 million kilometres.

Neowise will be closest to earth on its way out of the solar system on July 22 at a safe distance of 103 million kilometres and will be starting to fade with a shortening tail as it retreats from the sun’s heat and back to the icy depths of space. Comet Neowise originates from the Oort Cloud, where long-period comets reside and will return close to 6,800 years from now. Halley’s Comet is a short period comet originating from the Kuiper Belt. Along with this chart of the comet’s path, many smartphone astronomy apps will also guide you to our celestial visitor. Enjoy this spectacular comet every chance you can as you never know when the next bright will come to visit.

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Known as “The Backyard Astronomer”, Gary Boyle is an astronomy educator, guest speaker and monthly columnist for the Royal Astronomical Society of Canada. He has been interviewed on more than 50 Canadian radio stations and local Ottawa TV. In recognition of his public outreach in astronomy, the International Astronomical Union has honoured him with the naming of Asteroid (22406) Garyboyle. Follow him on Twitter: @astroeducator or his website: www.wondersofastronomy.com

By Gary Boyle – The Backyard Astronomer

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Comet Neowise – Wawa-news.com

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A bright comet is now in the evening sky and you can see it without a telescope. Comet F3 (NEOWISE) has been a fantastic object in the early morning pre-dawn sky but will be well placed below the Big Dipper to see and photograph over the next couple of weeks and hopefully into August. I have been following and imaging this comet since the first week of July and could see it even without binoculars (naked eye).

The comet was discovered on March 27, 2020, by the NEOWISE space telescope as it looks for near-earth objects that could potentially impact our planet. Measuring a little more than half the height of Mount Everest, this object falls into the category of a “once in a decade comet”.

Every year astronomers both amateur and professional observe 5 to 10 comets with telescopes. In most cases, they show a green nucleus from the sublimation of frozen chemicals such as ammonia and others. The extremely faint tail is seen when photographed but all comets are different in composition and appearance as Neowise does not appear green. The last bright comet that was visible to the naked eye for the whole world to see was Comet Hale-Bopp in 1997. And like Neowise, it too had a blue ion or gas tail and a fan-shaped dust tail created when comets round the sun as this one did on July 3 at a close distance of 43 million kilometres.

Neowise will be closest to earth on its way out of the solar system on July 22 at a safe distance of 103 million kilometres and will be starting to fade with a shortening tail as it retreats from the sun’s heat and back to the icy depths of space. Comet Neowise originates from the Oort Cloud, where long-period comets reside and will return close to 6,800 years from now. Halley’s Comet is a short period comet originating from the Kuiper Belt. Along with this chart of the comet’s path, many smartphone astronomy apps will also guide you to our celestial visitor.

Enjoy this spectacular comet every chance you can as you never know when the next bright will come to visit.

Known as “The Backyard Astronomer”, Gary Boyle is an astronomy educator, guest speaker and monthly columnist for the Royal Astronomical Society of Canada. He has been interviewed on more than 50 Canadian radio stations and local Ottawa TV. In recognition of his public outreach in astronomy, the International Astronomical Union has honoured him with the naming of Asteroid (22406) Garyboyle. Follow him on Twitter: @astroeducator or his website: www.wondersofastronomy.com

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Is Planet 9 Actually A Primordial Black Hole? – Forbes

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Conventional theory has it that Planet 9 —- our outer solar system’s hypothetical 9th planet —- is merely a heretofore undetected planet, likely captured by our solar system at some point over its 4.6 billion year history. 

But Harvard University astronomers now raise the possibility that orbital evidence for Planet 9 could possibly be the result of a missing link in the decades-long puzzle of dark matter. That is, a hypothetical primordial black hole (PBH) with a horizon size no larger than a grapefruit, and with a mass 5 to 10 times that of Earth.

How might it be detected?

In a paper accepted for publication in The Astrophysical Journal Letters, the co-authors argue that observed clustering of extreme trans-Neptunian objects suggest some sort of massive super-earth type body lying on the outer fringes of our solar system. Perhaps as much as 800 astronomical units (Earth-Sun distances) out.

So, the authors propose that a unique wide-field survey telescope, now under construction in Chile, will soon allow them to set new limits on the possibility that Planet 9 may indeed be a PBH instead of just an ordinary planet. If they exist, such PBHs would require new physics and go a long way towards solving the mystery of the universe’s missing mass, or dark matter. 

Our paper shows that if Planet 9 is a black hole, then comets residing in the outskirts of the Solar system (in the “Oort cloud”) would impact it, Avi Loeb, Chair of Harvard University’s Dept. of Astronomy and the paper’s co-author, told me. They would then be destroyed by its strong gravitational tide and within a second of accreting onto the black hole would produce a visible flare, he says.

For large enough comets, this flare of light would be detectable by the LSST’s 8.4-meter optical telescope.

The idea is that once in the vicinity of a black hole, small cometary bodies would melt as a result of Heating from the background accretion of gas from the interstellar medium onto the black hole, Amir Siraj, the paper’s first author and an Harvard University undergraduate, noted in a statement.  

The authors calculate that they would be capable of detecting the first such accretion flare within a few months of the LSST’s operation which is now slated for first light in 2021. 

Why the LSST?

The LSST will be unique in its ability to survey the entire sky about twice per week at a remarkable level of sensitivity, Siraj told me. We calculated that the flares from the accretion of a small body onto a Planet 9 black hole would be brightest near the optical band, where LSST operates, he says. And since Planet 9’s position is unknown, Siraj notes the fact that LSST surveys the sky so quickly maximizes its chance of catching a flare.

The authors say that such brief accretion flares would be detected at a rate of at least a few per year out to a distance of some 105 AU.  And they expect to be able to rule out or confirm Planet 9 as a primordial black hole within the first two years of the LSST’s operation.

Why would our own solar system harbor such an exotic primordial black hole?

Simply by their sheer numbers in the cosmos.  The authors estimate that it might be somewhat likely that our solar system gravitationally-captured at least once such primordial black hole over the eons.    

What would the detection of such an exotic black hole mean for physics?

Loeb says that the formation of primordial black holes would definitely represent new physics. The process that made them in the early universe is not predicted by the Standard Model of particle physics and cosmology, he says.

If Planet 9 is a primordial black hole, are there likely to be others within the galaxy?

If it is a black hole, there should be fifty quadrillions like it in the Milky Way alone, says Loeb.  

Loeb says there’s nothing to lose in using the LSST to look for such primordial black hole relics. Over the past four decades, lab searches for dark matter searches consumed tens of millions of dollars, he says.

“Our paper proposes to use LSST as a dark matter experiment, searching for primordial black holes at no extra cost,” said Loeb.

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