Earth safe from asteroid for 100 years says Nasa

NASA has announced that new telescope observations have ruled out any chance of the asteroid Apophis colliding with Earth in 2068. Photo / AP

Whew, now here's some good cosmic news: Nasa has given Earth the all clear for the next century from a particularly menacing asteroid.

The space agency announced this week that new telescope observations have ruled out any chance of Apophis smacking Earth in 2068.

That's the same 340-metre space rock that was supposed to come frighteningly close in 2029 and again in 2036. Nasa ruled out any chance of a strike during those two close approaches a while ago. But a potential 2068 collision still loomed.

First detected in 2004, Apophis is now officially off Nasa's asteroid "risk list."

"A 2068 impact is not in the realm of possibility anymore, and our calculations don't show any impact risk for at least the next 100 years," Davide Farnocchia of Nasa's Center for Near-Earth Object Studies, said in a statement on Friday.

Scientists were able to refine Apophis' orbit around the sun thanks to radar observations earlier this month, when the asteroid passed within 17 million kilometres.

Apophis will come within 32,000 kilometres on April 13, 2029, enabling astronomers to get a good look.

"When I started working with asteroids after college, Apophis was the poster child for hazardous asteroids," Farnocchia said. "There's a certain sense of satisfaction to see it removed from the risk list."