Astronomy notes is an educational resource for introductory astronomy classes for undergraduates. This section discusses the Hubble constant, Olbers' Paradox, Hubble's Law, the cosmological principle and the perfect...

This resource covers the nature and components of the Milky Way, including the disk, spiral arms, nucleus, dark matter halo, globular clusters, and central bulge; the interstellar medium, including gas, dust, HI and HII...

This slide set begins by discussing the amount of dark matter on galactic and larger scales by refering to the dark matter in the Milky Way. The next set of slides reviews the motivation for and the basic physics of...

This site offers new information pertaining to the Big Bang Theory. The new idea that they are proposing is that inflation took place at less than a tiny fraction of a second during which space underwent an enormous...

This online textbook teaches the user about how a science project is conceived, funded, and managed. They do this by telling a story about how NASA's High Energy Astronomy Observatory (HEAO) Program executed a science...