Subj: Satellite Nears Historic Rendezvous Date: 98-10-12 17:47:07 EDT From: AOL News Satellite Nears Historic Rendezvous .c The Associated Press By PAUL RECER MADISON, Wis. (AP) -- A small satellite launched more than two years ago is just weeks from becoming the first manmade object to be placed into an orbit of a distant asteroid, researchers said Monday. The Near Earth Asteroid Rendezvous, or NEAR, spacecrafts will fire rockets on Dec. 20 to settle into an orbit of an asteroid called Eros that is streaking across space some 163 million miles from Earth. Andy Cheng, a Johns Hopkins University researcher and the project scientist for NEAR, said that all instruments on the spacecraft are working well and that the small satellite is on target for its deep space meeting with Eros. The rocket firing comes while NEAR is still distant from Eros, and the satellite will not start orbiting the asteroid until Jan. 10, 1999. During months of circling the asteroid, the craft will be slowly lowered until its orbit is just 21 miles above the space rock, said Cheng. The craft will give the first prolonged, up-close look at an asteroid, which are minor planets, in space. Six instruments aboard NEAR will analyze the composition, magnetic field and mass of the asteroid, sending the data back to Earth by radio. Eros is something of a mystery. The rock is about the size of a mountain, 24 miles by 8 miles. It is a near-Earth asteroid, one whose orbit routinely carries it close to the orbit of Earth. Scientists don't know if the rock is solid or if it is a highly porous body with empty cavities or chunks of ice. But it similar to the asteroids that pounded Earth early in the planet's history. One such asteroid smashed into Earth 65 million years ago and is thought to have caused the extinction of the dinosaurs. Like most asteroids, said Cheng, Eros probably formed early in the history of the solar system. What isn't known is whether Eros was once part of a bigger planet or if it formed independently. ``There were many collisions in the early solar system,'' said Cheng. Sometimes huge chunks of a planet are knocked into space by such celestial smashups and became independent bodies. The Earth's moon is thought to come such a collision. Asteroids could also form from the leftover debris of planet-building. Bits of stray rock and dust slowly clump together until they form one object. The process may not be finished, said Cheng. He said there is some concern that wandering space rocks or gravel that imperil the NEAR. As NEAR approaches Eros, researchers will use cameras and instruments on board to search for any stray bits of rock or gravel that are still orbiting the asteroid. After months in orbit of Eros, researchers may attempt to put the craft onto the surface of the asteroid. Cheng said the spacecraft was not designed to land, but that is one option the researchers are considering. The density of Eros is unknown, but the asteroid is so small that its gravity force will be only a fraction of Earth's, making landing there less violent. But it would still be tricky steering the craft to a touchdown because Eros is so far away that there is a long delay between sending a signal and getting a response. Cheng said it takes about 45 minutes for a radio signal to make a round trip between Earth and NEAR. AP-NY-10-12-98 1746EDT