科技英语新闻:Large asteroid to pass Earth at closest approach: JPL

LOS ANGELES, May 2 (Xinhua) -- An asteroid will fly past Earth this fall at a close approach that will allow a close-up view of one of Earth's good-sized space rocks, NASA's Jet Propulsion Laboratory (JPL) announced on Monday.

"On November 8, asteroid 2005 YU55 will fly past Earth and at its closest approach point will be about 325,000 kilometers away," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at the JPL in Pasadena, Los Angeles.

"This asteroid is about 400 meters wide -- the largest space rock we have identified that will come this close until 2028."

Despite the relative proximity and size, "YU55 poses no threat of an Earth collision over, at the very least, the next 100 years, " Yeomans said in a press release.

"During its closest approach, its gravitational effect on the Earth will be so miniscule as to be immeasurable. It will not affect the tides or anything else."

"While near-Earth objects of this size have flown within a lunar distance in the past, we did not have the foreknowledge and technology to take advantage of the opportunity," said Barbara Wilson, a scientist at JPL. "When it flies past, it should be a great opportunity for science instruments on the ground to get a good look."

"The best resolution of the radar images was 7.5 meters per pixel," said JPL radar astronomer Lance Benner. "When 2005 YU55 returns this fall, we intend to image it at 4-meter resolution with our recently upgraded equipment at the Deep Space Network at Goldstone, California. Plus, the asteroid will be seven times closer. We're expecting some very detailed radar images."

Asteroid 2005 YU55 was discovered in December 2005 by Robert McMillan, head of the NASA-funded Spacewatch Program at the University of Arizona, Tucson. The space rock has been in astronomers' crosshairs before.

In April 2010, Mike Nolan and colleagues at the Arecibo Observatory in Puerto Rico generated some ghostly images of 2005 YU55 when the asteroid was about 2.3 million kilometers from Earth.