The National Optical Astronomy Observatory runs most of the big professional optical telescopes in the United States and this is their homepage. It includes information about the many facilities they run, some of the recent science...

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.

[Free Registration/Login may be required to access all resource tools.] What optics are and different types, and how they work and form images.

A collection of articles and interactives on the topic of telescopes and what we have learned from them about the universe, including information about some of the strangest phenomena. One section discusses the giant telescopes of the...

This series of images is a combined collection of over three museums' collections of optics images. The images are sorted by pages with about nine images per page and over ten pages.

Lowell Observatory homepage describes the history and current work done at the Lowell Observatory. Contains basic information about the telescopes and the results of work done by staff scientists. It is a national landmark.

The Space Environment Center (SEC) put together a slide show for use by teachers on Space weather. Begin with discussing solar emission and the sun itself. Then end with a summary of climatic effects of space weather, and a note on space...

This site, in German, offers numerous apps that illustrate common physics principles. Apps are organized into categories: mechanics, oscillations and waves, electrodynamics, optics, thermodynamics, the theory of relativity, physics of...

This site has an activity to make a hand-held telescope. "The Hubble Space Telescope that's orbiting Earth right now is the size of a school bus, but you can make a model of it that you can hold in your hands!"

Site provides quick facts and figures on the Hubble Space Telescope. Site includes spaceflight statistics, optical capabilities and data statistics and much more.

Homepage of Kitt Peak National Observatory (KPNO) which is the one of the premier astronomical observatory used by professional astronomers in the United States. Although the site is mostly geared toward the professional, the Kitt Peak...

Contains original clubhouse of the Springfield Telescope Makers, Inc. (1924), and the first large optical telescope (1930) built and owned by that kind of amateur society.