X-SciTech

Huge Asteroid Headed For Earth

March 11, 1998 / 6:42 PM EST / AP

An asteroid large enough to cause widespread destruction may be heading toward a 2028 collision with the Earth and will certainly pass closer to the planet than any such space object in modern times, astronomers said Wednesday.

"The chance of an actual collision is small, but one is not entirely out of the question," according to a notice filed by the International Astronomical Union.

"It has enormous destructive potential," said Steven Maran of the American Astronomical Society, but he added it will take several more years of observations before experts are certain of its path.

"It scares me. It really does," said Jack G. Hills, an asteroid specialist at the Los Alamos National Laboratory. "An object this big hitting the Earth has the potential of killing many, many people."

Maran said the best estimate is that the mile-wide space rock, called 1997 XF11, would pass closer to the Earth than the orbit of the moon, with the most likely separation from the center of the Earth being about 30,000 miles. The Earth has a radius of about 4,000 miles.

The estimate, said Maran, has a margin of error of more than 180,000 miles. This means a collision with Earth is theoretically possible, but uncertain at this time, he said.

Better estimates of the collision potential will be generated as astronomers plot the course of the asteroid through the heavens over the next few years.

Asteroids are routinely observed and plotted by astronomers around the world because of their potential for great destruction on Earth. Maran said that no asteroid of this size has ever been predicted to pass so close to the Earth in modern times.

An asteroid 6 to 10 miles across collided with the Earth about 65 million years ago and is thought to have caused the extinction of the dinosaurs, along with 75 percent of all other species.

Asteroid 1997 XF11 was discovered Dec. 6 by the University of Arizona Spacewatch program and was added to a list of 108 asteroids considered to be "potentially hazardous objects."

Observations made earlier this month by University of Texas astronomers showed that the asteroid would make its approach to the Earth on Oct. 26, 2028, at about 1:30 p.m. EDT.

"There is still some uncertainty to the computation," said the IAU bulletin.

The notice said the asteroid, which is on a wide-swinging, independent orbit of the sun, will move out of view to all but the largest telescopes over the next few months. It will become more visible once again in 2000.

And it in 2002, it is expected to pass within about 6 million miles of Earth on Halloween Eve. It will swing far out into space and then back toward the Earth about a quarter-century later.