Dog Bone-Shaped Asteroid Spied

Friday, May 5th 2000, 12:00 am
By: News On 6

ITHACA, N.Y. (AP) — Imagine the size of the dog.

Astronomers have at last gotten a close look at a familiar asteroid and discovered something unusual: It's shaped like a dog bone.

The asteroid, named 216 Kleopatra, is 135 miles long and about 58 miles wide — roughly the size of New Jersey — and is located in the main asteroid belt between Mars and Jupiter. Although Kleopatra was first discovered in 1880, its shape had been unknown until now.

Scientists used Cornell University's massive Arecibo Observatory telescope in Puerto Rico, the world's most powerful radar system. It obtained radar images that show the oblong asteroid with two large bulges at either end of a narrow arm.

``Kleopatra has the most unusual shape we've seen in the solar system,'' said Steven Ostro of NASA's Jet Propulsion Laboratory. ``The object's existence is a perplexing mystery that tells us how far we have to go to understand more about asteroid shapes and collisions.''

Astronomers think the asteroid's striking shape is the result of a violent cosmic collision. Their findings appeared in Friday's issue of the journal Science.

``The shape may have been produced by the collision of two objects that had previously been thoroughly fractured and ground into piles of loosely consolidated rubble,'' said R. Scott Hudson of Washington State University, an astronomer who observed the asteroid. ``Or, Kleopatra may once have been two separate lobes in orbit around each other with empty space between them, with subsequent impacts filling in the area between the lobes with debris.''

Its strong reflection of radar signals and its coloring indicate Kleopatra is mostly metal, possibly nickel-iron alloy, said Donald Campbell, associate director at Arecibo.