planet formation

Extrasolar meteors hint at distant planet formation

Candian astronomers say that detecting microscopic meteors from other solar systems could provide clues about the formation of planets like Earth. Dust streams from our sun’s stellar neighbours consist of tiny grains of pulverized rock ejected from a disk of dust and debris that commonly surrounds young stars, says Joseph Weingartner, a post-doctoral fellow at the University of Toronto’s Canadian Institute for Theoretical Astrophysics. According to Professor Norman Murray, associate director of CITA and co-author of the study, “if we can detect these grains and trace them back to the star system that they came from, we’d have very good evidence of planet formation going on in that system.” Weingartner presented the study Jan. 6 at the American Astronomical Society meeting in Seattle, Wash.

Jupiter-like planets formed in hundreds, not millions of years

An accepted assumption in astrophysics holds that it takes more than 1 million years for gas giant planets such as Jupiter and Saturn to form from the cosmic debris circling a young star. But new research suggests such planets form in a dramatically shorter period, as little as a few hundred years. The forming planets have to be able to survive the effects of nearby stars burning brightly, heating and dispersing the gases that accumulate around the giant planets. If the process takes too long, the gases will be dissipated by the radiation from those stars, said University of Washington astrophysicist Thomas R. Quinn.