February 18, 2000. Copyright 2000. Graphic News. All rights reserved.

ASTEROID RENDEZVOUS

LONDON, February 18, Graphic News: CLOSE-UP photos of Eros, taken by NASAÕs robotic NEAR spacecraft, show that the peanut-shaped asteroid is heavily cratered, sprinkled with boulders and light beige in colour.

The asteroid Ð named Eros after the Greek god of erotic love Ð is believed to be a solid rocky body that may have once been part of a larger object, such as a moon or planet.

The Near Earth Asteroid Rendezvous, or NEAR, spacecraft began orbiting the monster asteroid on Monday, the first time a craft has ever orbited an asteroid. The rendezvous took place about 160 million miles (256 million km) from Earth.

Shortly before the spacecraft went into orbit on ValentineÕs Day, NEAR detected a curious feature on the 21-mile (33.6 km)-long asteroidÕs surface: a heart-shaped crater at the lower end of the space rock.

There are mysterious bright patches, and even visible boulders some 50 yards (metres) in diameter.

But to project scientist Andrew Cheng, the most exciting aspect is the apparent stratified structure, which means that it might have been a chip off an old planet. If so, this would give scientists clues to the development of the solar system.

ÒEros has an ancient, heavily cratered surface,Ó Cheng said. ÒThere are also tantalizing hints that it has a layered structure, as if it were made up of layers like in plywood.Ó

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

Eros has a surface about as dense as the EarthÕs crust, far more solid than some asteroids that are little more than piles of loosely bound rubble. It also shows clear signs of the minerals olivine and pyroxene, which have been found on Earth, Mars and the Moon, and are commonly present in meteorites.

NEAR is currently orbiting Eros about 200 miles (320 km) above the asteroid, but over the next few months the spacecraft will slowly be brought closer and closer to its surface.

ÒA landing is a possibility that has been discussed,Ó Cheng said. ÒCertainly there are good science reasons Ð we want to get data from as close as we can.Ó

One fanciful-sounding reason space scientists are studying asteroids is their possible use as a training ground for human exploration.

ÒSome asteroids are far easier to land on than the Moon itself of course and many of them have hydrated minerals, certainly some of them are ex-comets,Ó Jet Propulsion Laboratory scientist Donald Yeomans said, suggesting that they may contain water, bound up in minerals.

ÒSo if youÕre going to have a human presence in space, particularly Mars, it might make sense to try out some of these technologies to turn water into usable hydrogen fuel and oxygen on asteroids and comets before you try the much more difficult task of trying to terraform Mars.
/ENDS

Sources: NASA, Jet Propulsion Laboratory, Reuters, Associated Press