Huge asteroid misses Earth but spotlights threat posed by space rocks

An asteroid bigger than the Eiffel Tower hurtled past Earth early on Saturday at a speed of 10,400 miles per hour, missing us by 4.6 million miles — not quite a close shave, but not so far in astronomical terms.

Had the fast-moving space rock, dubbed 2006 QQ23, been following a different trajectory, it could have slammed into our planet with an explosive force of up to 500 times that of the atomic bomb dropped on Hiroshima, Japan.

But if 2006 QQ23 is no cause for alarm, it’s a 1,150-foot reminder that somewhere in the cosmos another big and as-yet-unseen asteroid could be on a collision course with Earth.

“It’s 100 percent certain that we’re going to get hit, but we’re not 100 percent certain when,” says Danica Remy, president of the B612 Foundation, a nonprofit organization in Mill Valley, California, that’s working to protect the planet from asteroids.

Experts in so-called planetary defense are working on technologies to deflect large asteroids headed our way, but scientists say more needs to be done to detect them in time to take effective action.

Beyond planet-killers

Forget movies such as “Armageddon” and “Deep Impact.”

Astronomers have been scanning the skies for years, and they’ve turned up no giant “planet killers” that we need to worry about. The chance that an object like the 7.5-mile-wide “impactor” that is believed to have hit Earth and wiped out the dinosaurs 65 million years ago is considered virtually nil.

NASA estimates that at least 95 percent of asteroids one kilometer (3,280 feet) or larger have been cataloged, with none posing a threat to Earth. The more realistic danger comes from space rocks the size of 2006 QQ23, which could flatten an entire city, killing millions and causing widespread destruction in the event of a direct hit.

“The kind of devastation that we’d be looking at is more of at a regional level than a planetary level, but it’s still going to have global impact — on transportation, networking, climate, weather,” Remy says.

Just how devastating such a strike could be became unsettlingly apparent in May, when NASA, the Federal Emergency Management Agency and other agencies held a multiday simulation of an asteroid strike on New York City. The simulation showed that the impact of a 200-foot-wide object would kill 1.3 million people and destroy much of Manhattan.

The key to avoiding such a scenario is to go beyond the planet killers and find all the asteroids that could hit us. As Remy says, “The real issue is that we need to have an inventory of all the asteroids.”

Kelly Fast, manager of NASA’s Near Earth Object Observation program at the agency’s Washington, D.C., headquarters, agrees.

source: nbcnews.com