Roy S. Clarke took an early morning shuttle to New York Tuesday and came back with a 4.6-billion-year-old rock from outer space.

Clarke, who is curator of meteorites for the Smithsonian's Museum of Natural History, set out after a colleague called at 6 a.m. to inform him that Monday night a meteorite had fallen through the roof and two floors of the home of Robert and Wanda Donahue, of Wethersfield, Conn.

The meteorite, which came to rest under the Donahues' dining room table, came to Washington for a quick examination at the Smithsonian -- the world's largest storehouse of recovered meteorites -- before continuing across the continent yesterday for further study at the Battelle's Pacific Northwest Laboratories in Richland, Wash.

The meteorite -- or "space probe," as Clarke referred to it at one point -- is about the size of a softball with a thin black crust and a battleship gray interior, revealed by a rather dramatic gash where it encountered the Donahues' roof. It weighs 2,704 grams, about six pounds. As softball-size rocks go, it is pretty heavy.

Although hundreds or thousands of meteorites fall every year as their orbits intersect the Earth's, only five to 10 are recovered. Aside from putting a large hole in the Donahues' roof and interrupting a quiet evening of television at home, this meteorite is not unusual. It is made of iron, magnesium and silicates, olivine and pyroxine, according to Clarke, who described it as "a fairly normal sort of meteorite." For those who follow meteoric developments, he said it will be classified as an L Chondrite.

What is unusual about the Donahues' rock is that it was recovered so quickly and that it fell in the same town in which another meteorite fell 11 years ago. This coincidence -- two recovered meteorites falling within a mile of each other in 11 years -- was described by the normally understated Clarke as "incredible," "just remarkable" and "unbelievable."

The quick recovery of the meteorite, one of the few to fall on a building, also provides scientists with a rare opportunity to measure its radioactivity. Since meteorites orbit in the asteroid belt around the sun, they can be valuable, although primitive, sources of recent information about the sun, as well as giving clues about events millions and billions of years ago.

The Smithsonian, which has 1,500 of the world's 2,400 recovered meteorites, already has the other meteorite that fell in Wethersfield on April 8, 1971. That rock was a more modest affair -- 349.8 grams, less than a pound -- and is classified as a Hypersthene Chondrite.

At the moment, the latest Wethersfield meteorite, which the Donahues own, is on loan to the Smithsonian. That decision was made, according to Clarke, by the Donahues and a group of scientists who gathered in their living room after Clarke arrived Tuesday afternoon. Clarke carefully wrapped the rock in Saran Wrap, put it in his briefcase and had it in Washington by Tuesday evening. Less than 24 hours later it was on its way to the West Coast via Airborne.

"We hope eventually to get the meteorite," Clarke confided. As far as the commercial value is concerned, he said, the meteorite "is worth a tremendous amount to science," but the monetary value is something else. "There is very little, if any, market for these things. There are a few collectors, but that's about it."