Light travels from the stars throughtout the universe in waves of electricity and magnetism, called electromagnetic radiation. The two main features of light waves that human eyes can notice are brightness and color. However, our eyes aren't very precise measurers of either of these qualities. In order to get the most information out of incoming starlight, astronomers attach cameras, electronic sensors, and several other kinds of light-detecting devices to the eyepieces of telescopes. One of the most important instruments used to analyze starlight is the spectroscpe. A spectroscope separates light into the various colors that make it up -- its spectrum. Try analyzing light with a CD spectroscope then check out some of the images from the links below that astronomers are capturing and studying to learn more about the universe.

Astronomy Picture of the Day
A service of NASA, this site describes itself this way: "Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer." The explanations are good, filled with links to more information, and all past pictures are conveniently indexed by category: solar system, cosmos, space technology, people, etc.

National Space Science Data Center (NSSDC) Photo Gallery
A central clearinghouse for some of the most popular NASA images of solar system and astronomical objects. Easy-to-use index.

STScI/HST Public Information
Home site of the Hubble Space Telescope. Get the latest pictures and press releases, as well as archived images and information about the Hubble.

Anglo-Australian Observatory Colour Photographs
This collection of full color photographs from telescopes "down under" is truly remarkable. Astrophotographer David Malin is world-renowned for his color images of deep-sky objects. Many of these images are featured in the "Welcome to the Universe" exhibit.