Isle scopes lead hunt for 'killer asteroids'
An international task force has been set up to find such objects
The hunt for killer asteroids, led by telescopes to be built in Hawaii, is intensifying.
"The goal is to discover these killer asteroids before they discover us," University of Hawaii astronomer Nicholas Kaiser said at the meeting of the International Astronomical Union in Prague, Czech Republic.
The organization said yesterday it has set up a special task force to broaden its focus on "near-Earth objects," such as asteroids and comets, that could smash into Earth.
NASA scientist David Morrison, formerly with the UH Institute for Astronomy, will chair the task force. "We're now going to be finding such objects once a week instead of once a year," he said.
One of the lead telescopes will be the Panoramic Survey Telescope and Rapid Response System, known as Pan-STARRS, in Hawaii. When fully operational, the $50 million project will have a powerful array of four small telescopes capable of detecting objects as small as 330 yards in diameter and 100 times fainter than those observed by other telescopes, UH astronomers have said.
The first prototype telescope was dedicated in June on Haleakala, and site studies are under way to select the Maui mountain or the Big Island's Mauna Kea for the full array.
Experts at the conference said 1,100 objects have been identified that are about a half-mile or wider across, "large enough to not only take out a sizable European country, but threaten the entire world."
UH astronomer Robert Jedicke said NASA's Spaceguard Survey has identified 800 or more of the larger objects, and 103 objects of all sizes are on an impact risk watch list. The goal is to find 90 percent of the 1,100 objects by the end of 2008, he said.
"The ones that are larger than 150 yards in diameter are dangerous," he said. "Objects smaller than 150 yards get blown up or destroyed in the atmosphere."
He added: "The risk of a major impact in the next century is about one in a thousand, so if we want to entirely eliminate that risk, then we have to expand the surveys to be able to find that remaining 20 percent of objects much faster."
To expand the search to objects that would cause local devastation, he said programs must be developed that are much more sensitive to finding smaller objects. "So Pan-STARRS is the very first in the world of the next generation of surveys that go the extra mile to find smaller objects and retire most of the risk of an impact on Earth," he said.
It is hoped eventually to have a warning system for potentially dangerous asteroids and comets, Giovanni Valsecchi of Italy's National Institute of Astrophysics said at the conference.
This would allow time to send a rocket to deflect an object headed toward Earth or a spacecraft to bump it into another orbit, he said.
"Right now, unfortunately, there are no 'asteroid busters' or hot lines," said Andrea Milani Comparetti, University of Pisa mathematics professor.
The Associated Press contributed to this report.