* Russians want better protection after meteor blast
* European, U.S. scientists work on warning, defence systems
* Ideas include laser beams, gravity tractors, infrared rays
By Timothy Heritage and Gabriela Baczynska and Michael
Shields
MOSCOW/VIENNA, Feb 18 (Reuters) – What can man do to prevent
Earth being hit by meteorites and asteroids?
Russia has found, to its cost, that it has no answers. But
U.S. and European experts may be able to help with a few ideas
that at first glance seem straight out of science fiction,
including smashing spacecraft into asteroids, using the sun’s
rays to vaporise them, or blasting them with nuclear bombs.
That should come as some relief to the many worried Russians
who want something done immediately, even though scientists say
the explosion of a meteor over central Russia on Friday was a
once-in-a-lifetime event.
“We must create a system to detect objects that threaten
Earth and neutralise them,” Dmitry Rogozin, a first deputy prime
minister in charge of the defence industry, wrote on Twitter.
For all their nuclear missiles, he said that neither the
United States nor Russia could shoot down such meteors. Even
President Vladimir Putin held up his hands, saying no country
was able to protect against such events.
But there is hope for Russia as it looks for a solution.
Last week’s near miss from an asteroid half the size of a
football field, the same day as the meteor explosion, has
heightened awareness of the dangers Earth faces.
At a conference in Vienna on Monday, scientists said it was
time for man to do more to spot objects hurtling towards the
planet and to counter their threat.
LASER BEAMS AND GRAVITY TRACTORS
The European Union-funded NEO Shield consortium, whose aim
is to investigate the best ways to deal with an object hurtling
towards Earth, outlined some of its ideas in Vienna.
These included creating a “kinetic impactor” to fire a huge
spacecraft into an asteroid to alter its path; another was
making a “gravity tractor” by parking a big spacecraft near an
object and using thrusters to lead it away by using the weak
gravitational force as a cosmic tow-rope.
Exploding a nuclear device on or near an asteroid would be a
method of last resort, it said.
A U.N. “action team” for dealing with near-Earth objects
(NEOs) proposed setting up an International Asteroid Warning
Network, plus advisory groups on mounting space missions to
handle threats and planning for an impact disaster.
Timothy Spahr, director of the Minor Planet Center (MPC) at
the Smithsonian Astrophysical Observatory which collects
asteroid data, called for “rapid all-sky search capacity” using
a space-based infrared survey to detect objects much faster than
now.
The U.S. and European space agencies, NASA and ESA, warned
that man should also prepare for impacts that are unavoidable –
such as having procedures in place for wide-scale evacuations.
Detlef Koschny, responsible for near-earth object activity
at the ESA’s Space Situational Awareness programme, said
separately that it was now possible to determine possible impact
zones with just a few hours’ notice.
He cited the example of an object that hit the Sudan desert
in 2008. It was spotted only 20 hours before it hit and the
initial estimated impact zone of 2,000 km was narrowed down to
an area of the desert within a few hours.
“In a similar case in the future, civil authorities would be
able to tell the population in the narrowed-down area to stay
away from windows, glass or other structures and stay indoors,”
he said in emailed comments to Reuters.
ESA experts in Darmstadt, Germany, plan to set up a survey
to monitor the night sky using automated telescopes capable of
spotting objects before they enter the atmosphere, he added.
“NOT OUT OF STAR TREK”
In California, scientists are working on a system to harness
the power of the sun and convert it into laser beams that can
destroy, evaporate or change the course of asteroids.
“This system is not some far-out idea from Star Trek,” said
Gary B. Hughes, a researcher and professor from California
Polytechnic State University, San Luis Obispo.
“All the components of this system pretty much exist today.
Maybe not quite at the scale that we’d need – scaling up would
be the challenge – but the basic elements are all there and
ready to go.”
A University of Hawaii team of astronomers is also
developing a system with small telescopes called ATLAS that
would identify dangerous asteroids before their final plunge to
Earth.
The team predicts the system will offer a one-week warning
for a 50-yard (45-metre) diameter asteroid known as a “city
killer” and three weeks for a 150 yard (137 metre)-diameter
“county killer.”
“That’s enough time to evacuate the area of people, take
measures to protect buildings and other infrastructure, and be
alert to a tsunami danger generated by ocean impacts,” said
astronomer John Tonry.
Russian experts said, however, that constructing an early
warning system would hardly be worth the money as such events
are so rare – the last known meteorite strike on such a scale in
Russia was reported in 1908.
One Russian expert estimated the cost of such a system would
be $2 billion. Others put it higher.
“Also, spotting is one thing, but preventing impact is yet
another thing,” Igor Marinin, editor of a space journal
published by Russian space agency Roscosmos, told Reuters.
Referring to the injury toll of almost 1,200 after Friday’s
meteor explosion, most of them cut by glass, he said: “Compared
to the number of victims of car accidents or cancer every year,
this affected relatively few people.”
Back in Russia, some people are simply trusting in fate.
Konstantin Tsybko, a legislator from the city of Chelyabinsk
in the Ural mountain region, said on Monday: “Chelyabinsk
residents may feel safe because nothing like this will happen in
the next few hundred years.”
“This is the first town in the history of our civilization
to come under a space attack, survive this attack, and survive
it successfully,” he said.
(Additional reporting by Victoria Bryan in Frankfurt, Irene
Klotz in Miami and Sonia Elks in Moscow; Writing by Michael
Shields and Timothy Heritage; Editing by Jason Webb)
