An
asteroid as big as an aircraft carrier zipped by Earth yesterday in the
closest encounter by such a massive space rock in more than three
decades. Scientists ruled out any chance of a collision but turned their
telescopes skyward to learn more about the object known as 2005 YU55.
Its closest approach to Earth was pegged at a distance of 202,000 miles
at 6:28 p.m. [ET]. That’s just inside the moon’s orbit; the average
distance between Earth and the moon is 239,000 miles. The last time a
large cosmic interloper came that close to Earth was in 1976, and
experts say it won’t happen again until 2028. Scientists at NASA’s Deep
Space Network in the California desert have tracked the
quarter-mile-wide asteroid since last week as it approached from the
direction of the sun at 29,000 mph. If an asteroid that size would hit
the planet, Purdue University professor Jay Melosh said the impact would
carve a crater four miles across and 1,700 feet deep. And if it slammed
into the ocean, it would trigger 70-foot-high tsunami waves.
