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進入《TAIPEI TIMES 焦點》Scientists claim evidence for ninth planet
Mike Brown, a professor of planetary astronomy, speaks at the California Institute of Technology in Pasadena on Wednesday. Photo: Reuters
/ Reuters, CAPE CANAVERAL, Florida
The solar system might host a ninth planet that is about 10 times bigger than Earth and orbiting far beyond Neptune, research published on Wednesday said.
Computer simulations show that the planet, if it exists, would orbit more than 50 times farther from the sun than Earth, astronomers with the California Institute of Technology （Caltech） in Pasadena said.
The planet has not been observed directly, while another scientist said he is withholding judgement.
“It’s a pretty substantial chunk of our solar system that’s still out there to be found, which is pretty exciting,” said astronomer Mike Brown, whose work was published in the Astronomical Journal.
Brown and astronomer Konstantin Batygin, also at Caltech, modeled the hypothetical planet’s gravitational effects on several known bodies in the region.
The computer model predicted the location of known objects in a region known as the Kuiper Belt beyond Neptune and those were found in archived surveys as well.
At that point “my jaw sort of hit the floor,” Brown said.
Brown’s earlier research helped to demote Pluto in 2006 as the solar system’s ninth planet after other small, icy bodies were found beyond Neptune.
“All those people who are mad that Pluto is no longer a planet can be thrilled to know that there is a real planet out there still to be found,” Brown said.
The hypothetical gas giant is thought to be almost as big as Neptune, quite possibly with rings and moons.
“We could have stayed quiet and quietly spent the next five years searching the skies ourselves and hoping to find it, but I would rather somebody find it sooner, than me find it later,” Brown said.
Another scientist, Alan Stern, said he is withholding judgement on the planet prediction. He is the principal scientist for NASA’s New Horizons spacecraft, which buzzed Pluto last summer in the first-ever visit from Planet Earth. He still sees Pluto as a real planet.
“This kind of thing comes around every few years. To date, none of those predicts have been borne out by discoveries,” Stern said in an e-mail. “I’d be very happy if the Brown-Batygin were the exception to the rule, but we’ll have to wait and see. Prediction is not discovery.”
Additional reporting by AP
新聞來源：TAIPEI TIMES
