Experts: Tiny Collision Risk to Earth in 2071

ByABC News
November 8, 2000, 10:30 AM

L O S   A N G E L E S, Nov. 8 -- Scientists who announced last week that amysterious space object had a 1-in-500 chance of striking the Earthin 30 years have retracted their prediction, saying it poses littlethreat.

The object, which is either a small asteroid or piece of spacejunk, has virtually no chance of hitting the planet in 2030.However, scientists at the Jet Propulsion Laboratory in Pasadenasaid theres a 1-in-1,000 chance it could hit Earth in 2071.

This object is much more interesting than threatening, saidDonald Yeomans, manager of NASAs Near-Earth Object Program.

Oops, We Did It Again

Scientists downgraded the chance of a collision in 2030 afterexamining additional observations. The new data effectively ruledout the chance of an Earth impact in that year, according to theprograms Web site.

Predictions of the path of the object now indicate it will passno closer than 2.7 million miles to Earth about 11 times thedistance from the Earth to the moon.

The object, designated 2000 SG344, is either an asteroid about200 feet in diameter or a 35-foot-long Apollo-era rocket booster.It was discovered Sept. 29 through a telescope in Hawaii.

Before the new data was revealed, Yeomans had said that if theobject was an asteroid it could create a fairly sizable nuclearblast if it struck the Earth.

The retraction and downgrading was the second embarrassingasteroid announcement in recent years. Scientists at the MinorPlanets Center in Cambridge, Mass., generated headlines worldwidein 1998 when they announced that a mile-wide asteroid had a chanceof hitting Earth in 2028. The prediction was retracted a day laterwhen further calculations were made by JPL.

New Rules for Announcements

That incident led the International Astronomical Union to createnew guidelines for announcing events of such magnitude. New rulescall for announcements to be made after astronomers reach aconsensus that a risk to the planet exists and states that anannouncement be made publicly within 72 hours of such findings.