Asteroid Eros Is Yellowish and Cratered, Orbiter Shows

Eros, the first asteroid to be orbited by a man-made satellite, is very old, heavily cratered, strewn with large boulders and slightly yellow in color, according to new images from a science spacecraft.

Early data from a yearlong orbit of Eros by the Near Earth Asteroid Rendezvous spacecraft suggest that the asteroid is a solid rocky body that once may have been part of a larger body, such as a moon or planet.

“Eros has an ancient, heavily cratered surface,” Andrew Cheng, chief project scientist for the NEAR mission, said Thursday at a news conference in Washington, D.C. “There are also tantalizing hints that it has a layered structure, as if it were made up of layers, like in plywood.”

Such stratified features, Cheng said, could occur if the asteroid was once melted while a part of a planet, but the scientist said it was too early to draw any final conclusions.

There are bright splashes of lighter-color material on the asteroid that are still not identified, but scientists said it could be subsurface material ejected from impact craters.

Eros also has a large groove, rather like a deep wedge, gouged out of the middle of its potato shape. The groove, which researchers call a “saddle,” has large peaks on two sides. The interior of the saddle is smooth, suggesting it is a fresh feature or that slumping of soil has covered evidence of cratering.

NEAR slipped into the orbit of Eros, named for the Greek god of love, on Valentine’s Day and scientists are just starting to analyze data being collected by instruments aboard the spacecraft.

Eros is a space mountain, 21 by 8 by 8 miles in size, that orbits the sun. It now is about 160 million miles from Earth.