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Asteroid Twirling
Spinning hunk of gray rock.This twirling lump of rock might not impress you at first glance, but in fact it’s the product of NASA’s most powerful telescope technology.

The 200-mile wide asteroid pictured here, called Davida, was discovered a century ago at a German observatory. But until now, our view of the mammoth rock has been curbed by the limits of technology. More specifically, telescopic images of asteroids so far away are often nothing more than faint blobs warped by the Earth’s atmosphere.

But using the new Keck II telescope in Hawaii, scientists captured this detailed portrait last December. To an amateur, an asteroid closeup might pale in comparison to the iridescent plumes of stardust captured by Chandra and Hubble, but for scientists studying the formation of asteroids and planets, the detail is stunning.

Davida orbits the Sun in the main asteroid belt between Mars and Jupiter, and the pictures that make up this animation are some of the most detailed ever made of objects in this part of space.

Keck uses a technique known as adaptive optics to correct for the blurring caused by Earth’s changing atmosphere. Since Davida’s north pole faces the camera, only the northern hemisphere of the rock is visible. Astronomers are still working to discern the dark spots –- whether, for example, they are impact craters or the result of image processing.

Image courtesy W.M. Keck Observatory, NASA.

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