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(meteorobs) Fw: THE 2001 YB5 FALL OUT: GOOD AND BAD NEWS FROM THE SOUTHERN AND NORTHERN HEMISPHERES

Sent: Wednesday, January 09, 2002 8:21 AM
Subject: Fw: THE 2001 YB5 FALL OUT: GOOD AND BAD NEWS FROM THE SOUTHERN AND
NORTHERN HEMISPHERES


> Sad, sad news from the Cambridge Conference Network!

>
> > CCNet 6/2002 - 9 January 2002
> >
> > =============
> > (2) ASTEROID MISSES BY A WHISKER WHILE CANADIAN NEO PROGRAMME IS CLOSED
> DOWN
> >
> > From National Post Online, 8 January 2002
> >
>
http://www.nationalpost.com/home/story.html?f=/stories/20020108/1066000.html
> >
> > Asteroid misses Earth by a cosmic whisker. Devastation averted: B.C.
> program
> > that tracks space rocks just lost funding
> >
> > Margaret Munro and Joe Brean
> > National Post, with files from Agence France-Presse
> >
> > Between 20,000 and 50,000 years ago, a small asteroid about 24 metres in
> > diameter struck the Earth and formed this crater in Arizona that
measures
> > 1.2 km in diameter. The discovery of fragments of the Canyon Diablo
> > meteorite helped prove the feature was in fact an impact crater.
> >
> > An asteroid packing the power of hundreds of nuclear bombs and capable
of
> > wiping out a major country hurtled past Earth early yesterday in what
> > astronomers say was a close call.
> >
> > The giant space rock, known as 2001 YB5 and believed to be between 220
and
> > 490 metres across, was only twice as far away as the moon as it sped by
> > Earth at about 1:30 a.m. Eastern time.
> >
> > Experts said the distance -- about 600,000 kilometres -- is a whisker in
> > cosmic terms, and the rock would have caused global chaos had it smacked
> the
> > planet.
> >
> > "It could have vaporized the core of a city like Toronto, leaving a
crater
> > two to three kilometres across and creating a huge fireball and shock
wave
> > that would have knocked you off your feet in Vancouver," says University
> of
> > Victoria astronomer Dave Balam, who has been tracking asteroids for 25
> > years.
> >
> > He and other astronomers say the dust cloud kicked up by such an impact
> > could have exacted a huge global toll, triggering crop failures and
> climate
> > changes that could have been felt for years. "Such an object could
> literally
> > wipe out a medium-sized country if it impacted and lead to a global
> economic
> > meltdown," said British asteroid expert Benny Peiser, at Liverpool John
> > Moores University.
> >
> > Even worse, the asteroid could have crashed into the ocean, unleashing
> > devastating tsunamis.
> >
> > Had YB5 splashed down in the Pacific, low-lying coastal cities and
> > communities from Canada to Australia could have been hit, causing
millions
> > of deaths, says Professor Peter Brown at the University of Western
> Ontario,
> > who studies such space menaces.
> >
> > While asteroid YB5 is now safely past Earth, Prof. Brown and other
> > scientists say the fly-by is a reminder of how vulnerable the planet is
to
> > the huge wayward rocks that periodically come flying out of the asteroid
> > belt between Mars and Jupiter.
> >
> > Thousands of asteroids the size of YB5 are believed to be flying though
> > space but there is little information on their orbits, Prof. Brown said.
> As
> > in the case of YB5, they just suddenly appear on the radar screen.
> >
> > YB5 was only spotted heading toward Earth on Boxing Day by a Near-Earth
> > Asteroid Tracking survey telescope on Mount Palomar in California. NASA
> > designated the asteroid "potentially hazardous," a designation that
> applies
> > to any object larger than 150 metres that will come within 7.5 million
> > kilometres of our planet, says Don Yeomans, manager of NASA's Near Earth
> > Object Program office.
> >
> > By studying the light reflecting off the rock, scientists estimate it is
> > travelling at 30.6 kilometres a second. If it hit, Mr. Yeomans says, the
> > impact would have weighed in at 6,000 megatonnes.
> >
> > Astronomers stress that at no point did they think the asteroid would
> crash
> > into Earth -- a good thing, as there was too little time to have done
> > anything to deflect or destroy the asteroid.
> >
> > "It is a reminder of what is going to happen unless we track them more
> > efficiently than we do and make better preparations to defend our
planet,"
> > Dr. Peiser said.
> >
> > U.S. and British astronomers have been improving efforts to track
> > potentially hazardous asteroids. But a key component of the
international
> > effort -- Mr. Balam's asteroid-tracking program in Victoria -- was shut
> down
> > three weeks ago because of a lack of funding and support. "We just
> couldn't
> > keep it up," says Mr. Balam, noting how the program operated on a
> shoestring
> > budget for years.
> >
> > The National Research Council contributed time on its telescope in
> Victoria
> > more than 100 nights a year, and a U.S. foundation had been covering Mr.
> > Balam's salary as he tracked small asteroids and fed the information to
> the
> > international asteroid tracking community. The U.S. funding was cut last
> > year and no Canadian money could be found to replace it, despite an
> > endorsement from the Canadian Space Agency's meteorites and impacts
> advisory
> > committee, which wanted the program to survive.
> >
> > "It's really an incredible loss to Canadian planetary science, and a big
> > loss to the international community," says Prof. Brown, who sits on the
> > committee. He says Mr. Balam is one of the world's premier asteroid
> > trackers.
> >
> > "People like Dave are a national treasure," said Prof. Alan Hildebrand,
at
> > the University of Calgary, who chairs the CSA committee.
> >
> > Astronomers are becoming increasingly vocal about the risks of asteroid
> > collision, saying Earth has simply had a long run of good luck in
escaping
> > big cosmic debris.
> >
> > NASA's main focus is on identifying asteroids between one and 10
> kilometres
> > across. The number of these is estimated at 700, plus or minus 230. That
> > leaves the vast majority of space objects, which are under one
kilometre,
> > still to be detected and tracked.
> >
> > An asteroid believed to be about 10 kilometres across smashed into
> Mexico's
> > Yucatan Peninsula 65 million years ago, killing the dinosaurs and much
> other
> > life on Earth. That impact is believed to have triggered a firestorm and
a
> > dust cloud that obscured sunlight around the planet for decades.
> >
> > The space rock that flew by yesterday was "not in the same game," said
> Prof.
> > Hildebrand, who helped prove a giant asteroid killed off the dinosaurs.
> >
> > But Prof. Hildebrand says smaller rocks -- like 2001 YB5 -- pose a real
> > threat and should be tracked, since it might be possible to divert those
> > bound for Earth.
> >
> > In 1908, an asteroid believed to have been about 60 metres across
exploded
> > over Siberia with the force of 600 times the Hiroshima bomb, reducing a
> > 40-kilometre wide patch of forest to matchwood.
> >
> > David Jewitt, an astronomer at the University of Hawaii at Honolulu, has
> > estimated there is a 1% chance the Earth will be struck by a 300-metre
> > asteroid sometime this century.
> >
> > "Such an impact would deliver a withering 1,000-megatonne explosion and
> > cause perhaps 100,000 deaths," he said, adding that in a densely
populated
> > area, such as the U.S. eastern seaboard or Western Europe, the
fatalities
> > could rise into tens of millions.
> >
> > Copyright © 2002 National Post Online
> >
> > ==============
> -------------------------------------------------------------------
> > THE CAMBRIDGE-CONFERENCE NETWORK (CCNet)
>
>

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