'Little Bang' triggered solar system formation

FOR several decades, scientists have thought that the Solar System formed as a result of a shock wave from an exploding star-a supernova-that triggered the collapse of a dense, dusty gas cloud that contracted to form the Sun and the planets. But detailed models of this formation process have only worked under the simplifying assumption that the temperatures during the violent events remained constant.

Now, astrophysicists at the Carnegie Institution’s Department of Terrestrial Magnetism (DTM) have shown for the first time that a supernova could indeed have triggered the Solar System’s formation under the more likely conditions of rapid heating and cooling.

The results, published in the October 20, 2008, issue of the Astrophysical Journal, have resolved this long-standing debate.

“We’ve had chemical evidence from meteorites that points to a supernova triggering our Solar System’s formation since the 1970s,” remarked lead author, Carnegie’s Alan Boss. “But the devil has been in the details. Until this study, scientists have not been able to work out a self-consistent scenario, where collapse is triggered at the same time that newly created isotopes from the supernova are injected into the collapsing cloud.”