Lecture 32: The Origin of the Solar System

How did the Solar System form? This lecture examines the clues in the present-day dynamics (orbital and rotation motions) of the planets and planetary composition to the formation of the solar system. We will then describe the accretion model, where grains condense out of the primordial solar nebula, grains aggregate by collisions into planetesimals, then gravity begins to work and planetesimals grow into protoplanets. What kind of planet grows depends on where the protoplanets are in the primordial solar nebula: close to the Sun only rocky planets form, beyond the Frost Line ices and volatiles can condense out, allowing the growth of the gas giants. The whole process took about 100 million years, and we as we explore the solar system we will look for traces of this process on the various worlds we visit. Recorded 2006 Nov 7 in 100 Stillman Hall on the Columbus campus of The Ohio State University.