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考研英语报刊文章阅读及剖析(11) A distant, oversize world causes cosmic confusion The discovery of planets around distant stars has become like space-shuttle launches--newsworthy but just barely. With some 50 extrasolar planets under their belt, astronomers have to announce something really strange to get anyone s attention. Last week they did just that. Standing in front of colleagues and reporters at the American Astronomical Society s semiannual meeting in San Diego, the world s premier planet-hunting team--astronomer Geoffrey Marcy of the University of California, Berkeley, and his colleagues--presented not one but two remarkable finds. The first is a pair of planets, each about the mass of Jupiter, that whirl around their home star 15 light-years from Earth in perfect lockstep. One takes 30 days to complete an orbit, the other exactly twice as long. Nobody has ever seen such a configuration. But the second discovery is far stranger--a solar system 123 light-years away, in the constellation Serpens, that harbors one ordinary planet and another so huge--17 times as massive as Jupiter--that nobody can quite figure out what it can be. It is, says Marcy, a bit frightening. What s frightening is that these discoveries make it clear how little astronomers know about planets, and they add to the dawning realization that our solar system--and by implication Planet Earth--may be a cosmic oddball. For years theorists figured that other stars would have planets more or less like the ones going around the sun. But starting with the 1995 discovery of the first extrasolar planet--a gassy monster like Jupiter but orbiting seven times as close to its star as Mercury orbits around our sun--each new find has seemed stranger than the last. Searchers have found more hot Jupiters like that first discovery. These include huge planets that career around their stars not in circular orbits but in elongated ones; their gravity would send any Earthlike neighbors flying off into space. Says Princeton astronomer Scott Tremaine: Not a single prediction for what we d find in other systems has turned out to be correct. | 
