An asteroid bigger than an aircraft carrier will dart between the Earth and moon on Tuesday -- the closest encounter by such a huge rock in 35 years.But scientists say not to worry. It won't hit.
"We're extremely confident, 100 percent confident, that this is not a threat," said the manager of Nasa's Near Earth Object Program, Don Yeomans. "But it is an opportunity."
The asteroid named 2005 YU55 is being watched by ground antennas as it approaches from the direction of the sun. The last time it came within so-called shouting distance was 200 years ago.
Closest approach will occur at 6:28pm EST Tuesday when the asteroid passes within 202,000 miles of Earth. That's closer than the roughly 240,000 miles between the Earth and the moon.