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."

Two things are striking there:

1) That such a thing can happen at all.
2) That we were unbelievably lucky enough to witness an example of it happening.

Even if this happened to every star, how many would you have to be watching to expect to get a before-and-after of one of them in our lifetimes? There's a formal answer to that seemingly rhetorical question, and I'd like to see the math.