November 15, 2007—The violent formation of a new solar system has left one heck of a mess around a nearby star—and suggests that Earthlike planets may be far more common than previously believed, scientists say.

Using an infrared camera on the Gemini North Telescope in Hawaii, researchers recently detected heat that they believe originates from massive amounts of warm space dust surrounding HD 23514, a hundred-million-year-old member of the nearby Pleiades star cluster. The well-known cluster, also called the Seven Sisters, is located about 400 light-years from Earth.

That dust is very likely the remnants of a collision between two Earth-size rocky planets, as seen in this artist's depiction, the experts say.

The debris indicates that the star system is in the midst of a violent planetary formation process, as dust particles—the "building blocks of planets"—form into comets and small asteroids and eventually into larger bodies, research team member Inseok Song of the Spitzer Science Center said in a press release.

"In the process of creating rocky, terrestrial planets, some objects collide and grow into planets, while others shatter into dust," he added. "We are seeing that dust."

The finding suggests that rocky planets like Earth, Mars, and Venus could be quite common in the universe. The vast majority of the 200 or so alien planets found so far have been giant gas worlds; only a few are less than 20 times the mass of Earth and only one is considered habitable.

"This is the first clear evidence for planet formation in the Pleiades, and the results we are presenting strongly suggest that terrestrial planets like those in our solar system are quite common," study leader Joseph Rhee, a postdoctoral student at the University of California, Los Angeles, said in a statement.

The research is slated to appear in an upcoming issue of the Astrophysical Journal.

—Aalok Mehta

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