"A recently discovered space rock that could one day threaten Earth
turns out to be an object found seen more than four decades ago but
lost in space ever since.

The object, thought to be a burned out comet that now resembles an
asteroid, was catalogued as 2007 RR9 this year when found. When it was
last seen, in 1960, it carried the designation 6344 P-L. It's
considered a "potentially hazardous asteroid" because part of its
orbit is near the path our planet takes around the sun.

2007 RR9 is one of 886 (not 887) known asteroids bigger than 500 feet
(150 meters) that pass within 4.6 million miles (7.5 million
kilometers) of Earth. Astronomers did not give an exact diameter for
this one. The object poses no specific threat to the planet any time
in the foreseeable future. Over time, however, the orbit of a space
rock will shift and could cause it to hit the planet.

"The object was long recognized to be dangerous, but we didn't know
where it was," said SETI Institute astronomer Peter Jenniskens. "Now
it is no longer just out there.""

http://www.space.com/scienceastronom...oid-found.html

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