A 50-foot wide, 10,000-ton meteor that packs triple the force of the
nuke dropped on Hiroshima is nothing to scoff at. But in the grand
scheme of things, the meteor that hit Chelyabinsk, Russia,
last week is a cosmological runt. Space rocks as much as 100 feet
across are estimated to strike every hundred years or so and those like
the 160-foot diameter Tunguska meteor of 1908 hit maybe once a century.
Though
rare, these "killer asteroids" can wipe out a city the size of Moscow
and kill upwards of 30,000 in an instant. But when the University of
Hawaii's new meteor tracking systems come online, we'll be able to
forecast meteor strikes as accurately as we do blizzards.
It's
known as the ATLAS (Asteroid Terrestrial-impact Last Alert System) and
consists of a pair of observatories located about 60 miles apart, each
equipped with four, 10-inch telescopes outfitted with 100 MP cameras.
Together, these observatories would scan the visible sky twice a night.
If an object moves in relation to its previously recorded spot on any
given (or subsequent) night, that object is flagged for further
investigation. The telescopes, though relatively small, will be
sensitive enough to spot and estimate an incoming threat's exact impact
location and time, to the second. According to University of Hawaii
astronomer John Tonry, these telescopes are so detailed, they could spot
a match flare in NYC from the Golden Gate Bridge.
The project has been kicked around since at least 2010 but it appears that the recent flyby of 2012 DA14
has provided sufficient imperative to jump start the plan's funding
with a $5 million five-year grant by NASA's Near Earth Observation
Program. That's enough to build both observatories, develop the
necessary software, and staff the program for 48 months.
ATLAS will complement the Institute for Astronomy's Pan-STARRS project, a system that searches for large "killer asteroids" years, decades, and even centuries before impact with Earth. Whereas Pan-STARRS takes a month to complete one sweep of the sky in a deep but narrow survey, ATLAS will search the sky in a closer and wider path to help identify the smaller asteroids that hit Earth much more frequently. The project will take a closer and wider pass at the cosmos than the University of Hawaii's Pan-STARRS telescope array, which takes a month to complete one sweep of the sky in a deep, but narrow, survey.
ATLAS is expected to spot half of the 160-foot asteroids in the solar
system and two-thirds of the 460-foot planet killers that are thought
to be floating around us. This would give people in the impact zone
anywhere from a few days to a few weeks to evacuate, depending on the
size of the rock. And though the system's detection rate will likely
never top 75 percent, it will coordinate with other space-based comet
catchers like the NEO and Pan-STARRS telescopes, which peer further but over a smaller swath of sky, to maximize their coverage. "We
want to put ourselves in the way of discovering the unexpected," Tonry
said. As such, the ATLAS should also be able to track more benign
astronomical events like supernovas, variable stars, gravity waves, and
asteroid impacts out in the Kuiper belt.
Source : Gizmodo ( 21st Feb 2013 )
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