Most of us associate telescopes with amateur astronomy. Although there are more telescope options available to amateurs today than ever before, we know that binoculars can be the best way to get started in this fascinating hobby. Still, there will be a point where you want to see more: dimmer objects and more magnification of small objects. That is where a telescope can help.
Professional astronomers have long used telescopes to carefully study and measure objects in the night sky. Over 400 years ago, Galileo was perhaps the first astronomer to recognize the utility of the telescope for extending our sense of vision to the very distant. Ever since, this instrument has led the way to many discoveries. Not only does it magnify and intensify, but with modern detection methods (i.e. photography, electronic charge-coupled devices, radio receivers, x- and cosmic ray counters) we have extended human vision into wavelengths that are invisible to the eye.
This week we will study the detection, collection, focusing, and formation of images with telescopes. We will also examine the effects of Earth's atmosphere on electromagnetic radiation from space, and marvel at some of the ingenious ways that astronomers and telescope designers have circumvented these problems, with ground- and space-based telescopes. Finally, we will delve into the goals and tools of serious amateur astronomers and take a close look at telescopes that interested individuals can afford and use. One word of caution, though: this is a hobby that can become addictive.