University of Florida and NOAO/AURA/NSF

Never before have astronomers seen potential planet factories as large as some spotted in this new image, released May 26 at a meeting of the American Astronomical Society in Nashville.

Swirling disks of gas and dust -- the leftovers of star formation and raw material for planet formation -- extend outward from seven nascent stars. Each disk is 10 to 100 times larger than any previously seen, each covering an area of space up to 10,000 astronomical units (AU).

One AU is the distance from Earth to the Sun. The most distant frozen rocks in our solar system are thought to be roughly 1,000 AU from the Sun, and most of the solar system's objects are much closer in.

Theory holds that planets develop in disks like these, but it's not known how often the theory works. If these large disks follow theory, then "planets might exist much further from stars than we thought," said Richard Elston, of the University of Florida, who led the study along with Elizabeth Lada.

The findings may be interesting to planet hunters, because Earth-sized planets near a star -- if any exist -- are very hard to find, due to star's glare. "If the more distant reaches of the disk are conducive to planet formation, they will be easier to find once astronomers start looking there," Elston said.

The near-infrared photo at the top of this page, taken with the National Science Foundation's 84-inch (2.1-meter) telescope at Kitt Peak National Observatory in Arizona, shows a star cluster called NGC 1333, about 1,000 light-years away in the constellation Perseus.

Dust disks show up as bow-tie structures when they are oriented edge-on, as seen from Earth (see close-up at right). The densest portion of the disk creates a dark lane silhouetted against the star. [Does our solar system have an edge?]

-- Robert Roy Britt