Ducksters
Ducksters: Space Science: Astronomy for Kids
Kids learn about astronomy, the study of outer space including the stars, planets, comets, black holes, and the Solar System. History and astronomers in this astronomy for teachers and kids section.
University of Virginia
University of Virginia: How the Greeks Used Geometry to Understand the Stars
An article explaining how the Greeks were able to use their science and mathematics to predict where astronomical objects such as the Planets could be found in the nighttime sky even though their underlying premise was that the earth did...
NASA
Nasa: Imagine the Universe: Supernovae (Advanced)
Supernovae are divided into two basic physical types, including a description of supernova types and how they are classified based on the existence of hydrogen spectral lines. Definitions of key terms are provided.