Huge asteroid headed for close encounter with Earth
Date: 11/05/2011
A huge asteroid will pass closer to Earth than the moon Tuesday, giving scientists a rare chance for study without having to go through the time and expense of launching a probe, officials said.
Earth's close encounter with Asteroid 2005 YU 55 will occur at 6:28 p.m. EST (2328 GMT) Tuesday, as the space rock sails about 201,000 miles from the planet.
"It is the first time since 1976 that an object of this size has passed this closely to the Earth. It gives us a great -- and rare -- chance to study a near-Earth object like this," astronomer Scott Fisher, a program director with the National Science Foundation, said Thursday during a Web chat with reporters.
The orbit and position of the asteroid, which is about 1,312 feet in diameter, is well known, added senior research scientist Don Yeomans, with NASA's Jet Propulsion Laboratory in Pasadena, California.
"There is no chance that this object will collide with the Earth or moon," Yeomans said.
Thousands of amateur and professional astronomers are expected to track YU 55's approach, which will be visible from the planet's northern hemisphere. It will be too dim to be seen with the naked eye, however, and it will be moving too fast for viewing by the Hubble Space Telescope.
