Authored by Nick Strobel, "Astronomy Notes" is an educational resource for introductory astronomy classes for undergraduates. This section gives a extensive introduction to planetary science. Topics in this portion of the website include properties of planets, such as distance, mass, volume, density, and composition. There is also explanations on escape velocity, temperature, and gravity and how they affect planetary bodies. Other topics included are: the meanining of atmospheric colors, magnetic fields, the magnetic dynamo theory, seismology, differences between Mars, Earth, and Venus, and the properties of rings and moons in our solar system.