* Astronomy

NASA officials say the space agency is capable of finding nearly all the asteroids that might pose a devastating hit to Earth, but there isn't enough money to pay for the task so it won't get done.
The cost to find at least 90 percent of the 20,000 potentially hazardous asteroids and comets by 2020 would be about $1 billion, according to a report NASA will release later this week. The report was previewed Monday at a Planetary Defence Conference in Washington.
Congress in 2005 asked NASA to come up with a plan to track most killer asteroids and propose how to deflect the potentially catastrophic ones.

"We know what to do, we just don't have the money" -  Simon "Pete" Worden, director of NASA's Ames Research Centre.

These are asteroids that are bigger than 460 feet in diameter - slightly smaller than the Superdome in New Orleans. They are a threat even if they don't hit Earth because if they explode while close enough - an event caused by heating in both the rock and the atmosphere - the devastation from the shockwaves is still immense. The explosion alone could have with the power of 100 million tons of dynamite, enough to devastate an entire state, such as Maryland, they said.
The agency is already tracking bigger objects, at least 3,300 feet in diameter, that could wipe out most life on Earth, much like what is theorised to have happened to dinosaurs 65 million years ago. But even that search, which has spotted 769 asteroids and comets - none of which is on course to hit Earth - is behind schedule. It's supposed to be complete by the end of next year.
NASA needs to do more to locate other smaller, but still potentially dangerous space bodies. While an Italian observatory is doing some work, the United States is the only government with an asteroid-tracking program, NASA said.
One solution would be to build a new ground telescope solely for the asteroid hunt, and piggyback that use with other agencies' telescopes for a total of $800 million. Another would be to launch a space infrared telescope that could do the job faster for $1.1 billion. But NASA program scientist Lindley Johnson said NASA and the White House called both those choices too costly.
A cheaper option would be to simply piggyback on other agencies' telescopes, a cost of about $300 million, also rejected.

"The decision of the agency is we just can't do anything about it right now" - Lindley Johnson.

Earth got a scare in 2004, when initial readings suggested an 885-foot asteroid called 99942 Apophis seemed to have a chance of hitting Earth in 2029. But more observations showed that wouldn't happen. Scientists say there is a 1-in-45,000 chance that it could hit in 2036.
They think it would mostly likely strike the Pacific Ocean, which would cause a tsunami on the U.S. West Coast the size of the devastating 2004 Indian Ocean wave.
John Logsdon, space policy director at George Washington University, said a stepped-up search for such asteroids is needed.

"You can't deflect them if you can't find them. And we can't find things that can cause massive damage" - John Logsdon.

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What are the odds an asteroid or meteoroid will hit the Earth again? Pretty good, according to some scientists.
There are millions of these "rocks" out there, and about 200,000 to 400,000 of them get close enough to be classified as celestial objects that could come within range of our home planet.
But it only takes one, as anyone who has studied the dinosaurs will tell you. Many scientists believe an asteroid impact led to the extinction of the dinosaurs 65 million years ago.

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According to Russia's Institute of Applied Astronomy, about 400 asteroids and over 30 comets currently present a potential threat to the planet.
The institute's specialists are particularly concerned about an asteroid known as Number 29075, a kilometre-wide chunk of space rock that they believe "with a large degree of certainty" will strike the Earth on December 16, 2880.

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-- Edited by Blobrana at 22:56, 2006-10-24

They’re out there, hidden among a haze of stars — killer asteroids.
Now the world’s astronomers are keeping a wary eye to the skies for giant objects on a collision course with Earth.

Experts say there are about 1,100 comets and asteroids in the inner solar system that are at least a 1 kilometre across, and that any one of them could unleash a global cataclysm capable of killing millions in a single blinding flash.
On Thursday, the International Astronomical Union said it has set up a special task force to sharpen its focus on threats from such “near-Earth objects.”

"The goal is to discover these killer asteroids before they discover us" - Nick Kaiser of the University of Hawaii’s Institute for Astronomy, which hopes to train four powerful digital cameras on the heavens to watch for would-be intruders.

There are no asteroid busters to stop one right now, but scientists believe that one day a defence could be devised, such as using spacecraft to divert a killer comet.

The US Congress has asked NASA for a plan to comb the cosmos for even smaller, more distant objects, including asteroids just 1½ football fields (150 meters) across. The space agency is to catalogue their position, speed and course by 2020. Already, there are 103 objects on an “impact risk” watch list.
Scientists warn there are as many as 100,000 of these “smaller” heavenly bodies with the potential to take out entire cities or set off a tsunami like the killer wave that swept through the Indian Ocean in December 2004.

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