Scientists have begun to take a better-safe-than-sorry approach to defending Earth from a potentially devastating asteroid.

At a recent conference in California co-sponsored by The Aerospace Corp. and the American Institute of Aeronautics and Astronautics, astronomers discussed the need for various plans of defense should an asteroid capable of causing worldwide destruction threaten Earth.

There is "a constant, low-level threat" of such a situation, said Bill Ailor, director of the Center for Orbital and Reentry Debris Studies at The Aerospace Corp. "Fortunately, the likelihood of getting hit is pretty small."

The threat of getting hit by an asteroid or another near-Earth object depends on the NEO's orbit in conjunction to the Earth's orbit. If the two orbits overlap, there is a real risk of the NEO striking Earth. Though the timing of each varies enough to prevent a collision, the frequency of such near misses has recently been cause for alarm.

Rep. Dana Rohrabacher (R-Calif.) acted on the concern last month, introducing a federal bill which proposed an increase in NASA spending for finding and tracking 100-yard or larger asteroids in orbit near Earth.

Rohrabacher, chairman of the House of Representatives Space and Aeronautics subcommittee, wants to ensure there will be "more money for observation of outer space to spot and chart near Earth objects," said Aaron Lewis, Rohrabacher's spokesman. "There's been a few near misses" where the asteroid was in "very close proximity to the Earth."

The public may be quick to compare the scientists' plans to the 1998 movie "Armageddon," in which an asteroid was split in half with a nuclear weapon implanted by a crew of astronauts, but such a scenario would be impossible, according to Ailor. The main defense Earth has is moving the asteroid slightly off its orbit — slowing it down by as little as inches a second can change its movement enough to keep it from jeopardizing Earth.

Asteroids and other NEOs actually pass close by Earth nearly every day. NASA's Near Earth Object Program Web site includes a "Close Approaches" section, which details recent and future near misses. According to the site, two asteroids ranging anywhere from 459.2 to 2,066.4 feet in diameter are scheduled to pass near Earth Friday. One may come as close as eight million miles to Earth.

However, "the objects we know of aren't going to hit us in the next century or so," said visiting professor of physics Christopher Sirola, who also has a background in astronomy. If such a threat did materialize, he said, depending on the time available scientists could use either rockets or nuclear weapons to push the asteroid out of orbit.