Whew! Big asteroid no longer threat to Earth AP 1/10/2013 10:07:39 PM (AP) Whew! Big asteroid no longer threat to EarthBy SETH BORENSTEINAP Science WriterWASHINGTONNASA says a big asteroid is no longer even a remote threat to smash into Earth in about 20 years.Astronomers got a much better look at the asteroid when it whizzed by Earth on Wednesday. They recalculated, determining it wasn't on path to hit Earth on April 13, 2036 as once feared.At more than 1,000 feet wide, the rock could do significant damage but not cause worldwide extinctions.About nine years ago, when astronomers first saw the asteroid, they thought there was a 2.7 percent chance that Apophis (uh-PAH'-fihs) would smack into our planet. Later, they lowered the chances. The asteroid is named after an evil Egyptian mythical serpent.Donald Yeomans, who manages NASA's asteroid-tracking office, said now the asteroid won't get closer than 19,400 miles.