Eyes on Asteroids

Hello, 1862 Apollo.

Yes, your visit will be quick as you whip by planet Earth today, and you aren't getting close enough for us to get a good look unless we have a pretty good telescope in our backyard. But every time an asteroid comes close, we start to wonder when we will get hit.

No one is worried about 1862 Apollo hitting Earth -- its approach puts it 6.84 million miles away as it passes by. So named because it was the 1,862nd asteroid to be discovered, 1862 Apollo travels with a tiny moon as well.

The Odds

What are the odds an asteroid will hit Earth again? Pretty good, according to some experts.

There are millions of shooting stars, and about 200,000 to 400,000 of them get close enough to be classified as asteroids that could come within range of Earth. But it only takes one as anyone who has studied the dinosaurs will tell you.

Apollo 9 astronaut Russell Schweickart believes it is simply a matter of time before another asteroid targets Earth. "It could be 20 years, or 100 years, or 1,000 years."

Schweickart is one of the founders of the B612 Foundation, which is studying how to alter the orbit of an asteroid to keep it from hitting Earth.

"It's a very infrequent occurrence, an asteroid impacting the earth, but when it happens, it will be devastating."

Schweickart is frustrated because he believes this is a project that should be taken on by an international organization. He contends there is no way to predict when an asteroid will hit Earth, or where it will hit, so no single government should be held responsible for asteroid avoidance.

He wants to see the United Nations set up an agency mandated to prevent an asteroid from hitting Earth, and he has planned a series of four meetings around the world to develop a comprehensive plan. He anticipates a project that would cost several hundred million dollars, a burden for any single country, but something much more practical as a combined effort.

How would you keep an asteroid from hitting Earth?

Schweickart outlined a three-step program.

Early Warning: You have to keep an eye out to know that they're coming. NASA currently has a budget of $4.1 million to look for asteroids.

Take Action: Develop the ability to deflect an asteroid. Some technology is available now, but it will require propulsion that doesn't yet exist — nuclear reactors that could power ion-propulsion systems for interplanetary spacecraft.

Make a Decision: Some agency has to decide to do this and fund it. This isn't about ducking as a bullet goes past your head, this is about seeing what is coming your way decades ahead and believing the laws of gravity.

An Ounce of Prevention

Edward T. Lu is a NASA astronaut who has developed a plan of action for deflecting an asteroid. He and fellow astronaut Stan Love have come up with the concept of a Space Tug, a rocket that would launch to the same orbit as an asteroid threatening to hit Earth, and alter the asteroid's orbit by pushing in the direction of its orbital motion.

Lu told ABC News, "You don't have to change much -- 100,000 of a mile an hour is enough, 10 years ahead of time -- to cause an asteroid to miss the rendezvous with Earth."

NASA is taking some steps to learn more about asteroids.

Chris McKay is a planetary scientist with the Ames Research Center as well as the deputy lead scientist for the Constellation Program. Constellation is the program to go back to the moon and on to Mars. Orion is the vehicle that will carry the astronauts, using an Ares rocket. McKay is exploring ways to use Orion for other missions, such as sending a crew to land on an asteroid.

"It is exciting to think about rendezvousing with an asteroid and bringing back samples. What we could learn about the origins of the Earth is mind-boggling," he said.

Though McKay is excited about the possibility of landing on an asteroid, he says right now there is no mandate to start deflecting asteroids.

"Right now there is nothing out there that we know of with our name on it, but if we did find something, this mission could give the knowledge to deter a disaster."

An ounce of prevention is the mantra for scientists concerned about asteroids smacking into Earth. Both Schweickart and McKay use the failure of the levees in New Orleans after Katrina as an example of poor planning on all levels of government.

Is getting hit by an asteroid something to lose sleep over? Probably not, says Schweickart. He says people should be more concerned about the government's role in watching for an asteroid.

NASA's mandate is the Near Earth Object Observation Program, with the scientific objective to track the near Earth asteroids larger than one kilometer in size. NASA is not responsible for preventing an asteroid that it tracks from hitting Earth. No agency has that mandate right now.

And the lack of a plan, says Schweickart, is something that causes him to lose sleep.