AST 309 Lecture Notes - Lecture 18: Formation And Evolution Of The Solar System, Protostar, Molecular Cloud
Document Summary
We didn"t observe the origin of the solar system, so we have to develop theories that match circumstantial evidence - what the solar system is like today. Observed data (today) are mostly consistent with a theory that all the planets formed out of the same cloud of gas at the same time. Some of the wide variety seen within the existing planets may be due to chance events like collisions. Discovery of planet-forming disks and planets around other stars implies that planet formation is common in our galaxy. Today"s best hypothesis: planet formation in a nutshell. Earth, sun and rest of solar system formed from cloud of gas and dust about 4. 6 billion years ago. Properties of individual planets reflect their proximity to the hot proto-sun. Some planets have experiences major perturbations and/or collisions. Comets and asteroids are debris left over from solar system formation. Test against real data to look for contradictions, and make modifications where needed.
