NASA
Collecting Electromagnetic Radiation
Astronomy is literally over your head, but this lesson will explain how we study it. Young scientists make telescopes, calculate and compare the light gathering power of lenses, and simulate detection of infared radiation....
Texas Education Agency
Texas Gateway: What Are Telescopes Used For?
Scientists use telescopes to study the various components of the universe. How do telescopes work? Learn here about the electromagnetic spectrum and the various types of telescopes.
CK-12 Foundation
Ck 12: Physical Science: Optical Instruments
[Free Registration/Login may be required to access all resource tools.] What optics are and different types, and how they work and form images.