This is only a shock to billion-year evolution-by-gravity mouth-breathers...
excerpt
Some 460 light-years away in the constellation Centaurus, a thick disk of dust swirled around a young star named TYC 8241 2652 1, where rocky planets like our own were arising. Then, in less than 2 years, the disk just vanished. That’s the unprecedented observation astronomers report in a new study, out today. Even more intriguing: The same thing may have happened in our own solar system.
Born about 10 million years ago, the TYC 8241 2652 1 system was chugging along just fine before 2009. Its so-called circumstellar disk glowed at the infrared wavelength of 10 microns, indicating it was warm and lay close to a star — in the same sort of region that, in our own sun’s neighborhood, gave rise to the terrestrial planets Mercury, Venus, Earth, and Mars. The infrared data reveal that the dust was about 180°C and located as close to its star as Mercury is to the sun.
By January 2010, however, nearly all infrared light from the dusty disk had vanished. “We had never seen anything like this before,” says astronomer Carl Melis of the University of California, San Diego. “We were all scratching our heads and wondering what the hell did we do wrong?” But subsequent observations with both infrared satellites and ground-based telescopes confirmed the surprising discovery, he says: “The disk was gone.”
Melis and his colleagues report the mystery online today in Nature — but they don’t know what caused it. “It’s very bizarre,” he says. “Nothing like this was ever predicted.” He says there’s no way something could eclipse the infrared-emitting disk for more than 2 years, because such an object would be immense. Furthermore, the star itself didn’t fade.
Melis speculates that an earlier collision between two objects — perhaps two boulders, two asteroids, or even two planets — orbiting the star produced the dust grains that emitted the infrared light. Then either the star’s light blew the dust out of the planetary system or the dust plunged into the star.
“It’s a really interesting mystery,” says astronomer Scott Kenyon of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, who was not affiliated with the discovery team. “The observations certainly seem correct. It’s sort of amazing to have the dust in one of these disks go away so quickly. It’s hard to know exactly what happened.”
