Science: New Neighbors

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Hints of other planets

Peering out across the broad, lonely wastes of space, scientists have long wondered if there were intelligent beings on other worlds. Now two astronomers have found strong evidence that planets like earth and its eight celestial cousins in the sun's solar system may be common in the Milky Way. In a new, highly detailed photograph of Beta Pictoris, a neighborly 293 trillion miles from the sun, Bradford Smith of the University of Arizona in Tucson and Richard Terrile of the Jet Propulsion Laboratory in Pasadena, Calif., have discovered that the star is encircled by a dim disc of gas and solid particles. The astronomers believe that those particles may be the signs of newborn planets and worlds in formation. The spectacular image is the first visual evidence of another solar system, raising the possibility that extraterrestrial life may some day be found. "The time will have to come when we realize that we're not the center of the universe," says Terrile. "The galaxy may be teeming with life. There may be millions of civilizations."

The finding was not entirely unexpected. A team of scientists at the Jet Propulsion Lab that analyzed emanations of heat from the orbiting infrared astronomy telescope (IRAS) announced last spring that four nearby stars appeared to be surrounded by some kind of matter. At the Cerro Las Campanas Observatory in central Chile, Smith and Terrile trained a 100-in. telescope on one of those stars, Beta Pictoris, which was then visible high in the sky. Taking a photograph, however, turned out to be extremely difficult. Beta is twice as bright as the sun, and its light easily overwhelms that from any faint material around it. Trying to discern the surrounding matter, says Terrile, was "like trying to see a match next to a flashbulb."

The two scientists finally employed an instrument called a coronagraph, which can block out the most blinding light of a star, making a kind of eclipse. With Beta in shadow, Terrile and Smith then attached a special detector to the telescope that picked up the weakest light signals around Beta. The resulting image of an encircling disc looked remarkably similar to our own solar system. Analyzing the configuration of the disc with a computer, they found that some matter may have condensed to form planets.

Terrile and Smith point out that if a Beta planetary system does exist, it is an unlikely place to find galactic citizens: the distant network is only about 100 million years old, in contrast with the 4.5 billion years of earth. The most primitive form of life did not appear on earth until 1 billion years later. Some astronomers, moreover, are skeptical of the pair's planetary speculation. Says Fred Gillett of the National Optical Astronomy Observatories in Tucson and a member of the IRAS team: "It would be impossible, using this technique, to detect large bodies."

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