Formation of Jupiter and Saturn studied

A US researcher says a theoretical model is yielding clues as to how giant gaseous planets such as Jupiter and Saturn might have formed and evolved. Alan Boss of the Carnegie Institution for Science says giant gaseous planets are thought to form in rotating disks of gas that surround stars in the early stages of their lives. Observations have shown sun-like stars undergo periodic outbursts, lasting about 100 years, which transfer mass from the disk onto the young star, increasing its luminosity. It had been thought such outbursts could interfere with the processes that would form giant planets out of the disk of gas, researchers said. Boss developed highly detailed, three-dimensional models suggesting that regardless of how giant gaseous planets form they could survive periodic outbursts of mass transfer from the gaseous disk onto the young star. One model similar to our own solar system was stable for more than 1,000 years, while another model containing planets similar to our Jupiter and Saturn was stable for more than 3,800 years, a Cornell release reported Wednesday. The models showed these planets were able to avoid being forced to migrate inward to be swallowed by the growing proto-sun, or being tossed completely out of an evolving planetary system by close encounters with each other. "Gas giant planets, once formed, can be hard to destroy," Boss said, "even during the energetic outbursts that young stars experience." Searches for extrasolar gas giant planets have found them to be present around about 20 percent of sun-like stars.