Xray defined. Visible light defined. Infrared defined. Radio defined. Go to Flash version.
Instructions: Click on the telescope on the left that you're interested in. This will open a new window. Then you can click on the telecsope image to see how the light enters the telescope and gets directed towards the focal point.
Planisphere to choose celestial objects. How telescopes work.
Go to NASA homepage. Go to NASA new vision page.
Refractor telescopes Newtonian telescopes Hubble telescope Spitzer telescope Chandra telescope Radio telescopes