Article: Asteroid 2010 WA Close Approach Update from 16 November 2010

This photo taken on Nov. 16, 2010 shows the asteroid 2010 WA as it passes within 24,000 miles (38,000 kilometers) as seen by astronomers using a telescope at the Magdalena Ridge Observatory in New Mexico. It is about 10 feet (3 meters) wide. Credit: Dr. William Ryan/Magdalena Ridge Observatory/2.4-meter Telescope/New Mexico Tech

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The space rock, called asteroid 2010 WA, flew within 24,000 miles (38,000 kilometers) of Earth Tuesday night (Nov. 16).

The asteroid was tiny, just 10 feet (3 meters) across and posed no threat of hitting Earth. In fact, it was so small that it would break apart before passing through Earth's atmosphere, NASA scientists said.

Astronomers with the Magdalena Ridge Observatory near Socorro, N.M., trained a 2.4-meter telescope on the asteroid as it sailed past the Earth Tuesday at 10:44 p.m. EST (0344 Nov. 17 GMT).

What they found was surprising.

"We measured the rotation rate of the asteroid at about 31 seconds," astronomer Eileen Ryan, the observatory's director, told SPACE.com in an e-mail. "This makes it the second fastest rotating asteroid discovered to date."

The fastest spinning asteroid currently known is an asteroid called 2010 JL88, which spins once every 24.5 seconds and was also discovered using Magdalena Ridge Observatory's telescope, Ryan said.

Despite its small size, the asteroid still appeared as a bright object on a dark background in images taken by the observatory's telescope, which is built for tracking near-Earth objects (NEOs) and satellites, Ryan said.

"Because of this unusual feature, tracking fast-moving NEOs like 2010 WA is fairly easy for us," Ryan said.

The next time asteroid 2010 WA will come anywhere near Earth's cosmic neighborhood is in September 2013, but that pass will be considerably farther - about the equivalent of the distance between the Earth and the sun (93 million miles, or 150 million km), Ryan added.

Asteroid 2010 WA was the fourth space rock in three months to zip by the Earth within the orbit of the moon.

Link: Space.com article