Science: Asteroid hunters want to launch private telescope

In a bold plan unveiled Thursday, the group wants to launch its own space telescope to spot and track small and mid-sized space rocks capable of wiping out a city or continent. With that information, they could sound early warnings if a rogue asteroid appeared headed toward our planet.

Asteroids are leftovers from the formation of the solar system some 4.5 billion years ago. Most reside in the asteroid belt between Mars and Jupiter but some get nudged into Earth's neighborhood.

But the group thinks more attention should be paid to the estimated half a million smaller asteroids similar in size to the one that exploded over Siberia in 1908 and leveled more than 800 square miles of forest.

Added former Apollo 9 astronaut Rusty Schweickart: "The current priority really needs to be toward finding all of those asteroids which can do real damage if they hit or when they hit. It's not a matter of if; it's really a matter of when."

Asteroids are getting attention lately. NASA nixed a return to the moon in favor of a manned landing on an asteroid. Last month, Planetary Resources Inc., a company founded by space entrepreneurs, announced plans to extract precious metals from asteroids within a decade.

Since its birth, the Mountain View, Calif.-based B612 Foundation has focused on finding ways to deflect an incoming asteroid. Ideas studied include sending an intercepting spacecraft to aiming a nuclear bomb, but none have been tested.