John Bally will discuss the birth of stars, the formation of planets and the origin of the solar system during his live astronomy show "Formation of Planetary Systems" at CU-Â鶹ӰԺ's Fiske Planetarium on Friday, March 3, and Tuesday, March 7, at 7:30 p.m. For centuries, astronomers have theorized about how the Earth and Sun formed. "But now, for the first time in history, we are beginning to understand the birth of stars and planets," said Bally, an associate professor in the astrophysical and planetary sciences department at CU-Â鶹ӰԺ.