Creator's description:  The Nine Planets is an overview of the history, mythology, and current scientific knowledge of each of the planets and moons in our solar system. Each page has text and images, some have sounds and movies, most provide references to additional related information. Interplanetary spacecraft have revolutionized planetary science. Very little of this document would have been possible without the space program.

CoursePal comments:  This free online course provides a detailed breakdown of our solar system and its planets. No registration is required and you can start any time and work at your own pace.  Contains little or no advertising.