Asteroid 2005 YU55 is scheduled to skirt Earth on Nov. 8, giving astronomers an unparalleled opportunity to make observations about the space rock. Over four hundred yards across, the asteroid is large enough to cause damage on a regional scale if it were to make contact. Luckily, it will just miss Earth, whizzing past at the decidedly cozy distance of 201,700 miles - closer than our own Moon.
The near-miss gives astronomers an opportunity to take what amounts to a space sonogram of 2005 YU55, sending out microwaves that will bounce off the asteroid and return to Earth carrying highly accurate information about its surface. This use of radar 'echoes' to observe images as far away as Saturn is known as radar astronomy and it works best when the rebounding signal is strong. The proximity of the 2005 YU55 will allow for an unprecedented ability to make observations about a near-space object. According to the NASA Jet Propulsion Laboratory site, scientists hope to obtain images of the asteroid as fine as about 7 feet per pixel, which will reveal in highly articulated detail the asteroid's surface features, shape, and dimensions.
The two devices that will be used for the project are the 230-foot Deep Space Network (DSN) antenna at Goldstone Deep Space Communications Complex in the Mojave Desert in California and the 1,000-foot diameter telescope at the Arecibo Planetary Radar Facility in Puerto Rico. The largest and most sensitive of the DSN antennae, the 230-foot diameter antenna is full steerable and capable of tracking a spacecraft travelling more than 10 billion miles from Earth. Though the Arecibo telescope is not fully steerable, it is 30 times more sensitive than the antennae, making it an ideal complement.
NASA will begin tracking the asteroid at 9:30 A.M. on November 4 using the Goldstone antenna; tracking will continue at Goldstone for a few hours a day from Nov. 6 to Nov. 10. On Nov. 8, Arecibo will begin its own radar observations of the asteroid, which will make its closest approach to Earth at 3:28 P.M. PST.