Never fear, however. The space agency says that although next week's flyby of Asteroid 2005 YU55 will bring the rock closer to our home planet than even the moon gets, the asteroid will cruise safely past, leaving in its wake not destruction but data.
The agency has already begun using radio waves to scan the 1,300-foot-wide space rock, which will get closest to Earth on Tuesday at about 3:30 p.m. PT. With antennas at its Deep Space Network at Goldstone, Calif., and the Arecibo Planetary Radar Facility in Puerto Rico, NASA hopes to gather a wealth of detail about the asteroid's surface features, shape, dimensions, and other physical properties.
An extraterrestrial rock hasn't come this close to Earth since 1976, and we won't witness another such close encounter till 2028, NASA says. YU55 itself hasn't come this near for 200 years. Amateur astronomers who want to check it out for themselves will need a telescope with an aperture of 6 inches or larger, the agency says.
Radar observations made of YU55 in 2010 reveal it to be approximately spherical and slowly spinning, with a rotation period of about 18 hours.
NASA's Near-Earth Object Observations Program, aka "Spaceguard," looks out for rocks like YU55 and plots their orbits to see if any are a threat.