Rock Our Worlds: SFSU Scientist Models Creation of Planets

When Kansas sang that "All we are is dust in the wind," the band guaranteed itself a lifetime of references in college astronomy courses for nonmajors. "Dust" isn't just a great song to play at the 10th-grade junior prom -- its overriding message is essentially correct. Using far more math and far less percussion, San Francisco State University astronomy professor Joseph Barranco has created three-dimensional models demonstrating how churning dust in the vicinity of distant stars could create planets.

A paper coauthored by Barranco appears in today's edition of The Astrophysics Journal (it's incredibly light reading -- note how they discuss their "deep (14.5 r 23), 20 night survey for transiting planets in the rich ~550 Myr old open cluster M37." You can peruse the abstract here).

The über-Cliffs Notes version of Barranco's work follows. The most important factor in the formation of planets could be the same one that results in you spilling airline coffee on your nice white shirt: turbulence. The prevailing theory of planet formation, "gravitational instability," proposed that dust eventually becomes dense yet thin enough to break into county-sized blobs, which collide and form planets.

Barranco's research, however, indicates that turbulence forces dust and gas to keep swirling, preventing it from becoming dense and thin enough for gravitational instability to commence. Prior researchers used two-dimensional models to explore planetary formation. Barranco's 3-D models reveal previously hidden factors that induce turbulence and stave off gravitational instability.

"These results defy the proposed solution of how planets are formed," the professor said. "Scientists have long been using gravitational instability theory to explain how millimeter-size particles grow to kilometer-size, but these new simulations open new avenues of investigation. Perhaps massive storms, similar to hurricanes found on the Earth or Jupiter, provide clues about how tiny dust grains clump together to become kilometer-size boulders."

If Barranco is correct that planets owe their existence to gargantuan galactic storms, then, perhaps, the Scorpions' "Rock Me Like a Hurricane" will become the next song of choice for well-meaning astronomy instructors trying to make things relevant for the kids.