Measurement, Time, & The Scale of the Universe

The background music here is really annoying, but he does make quick work of the basic definitions.

http://www.youtube.com/watch?v=Iimklyw9T3U&feature=related

If your math skills are good (think sin, cos, tan…) you may be interested in this definition of what a parsec is…

Cosmic Distances & Light Speed

The Scale of the Universe
The Scale of the Universe Interactive Applet

Light, Optics, and Telescopes

Light

Atmosphere & Optical Telescopes

The following link will take you to a good history of telescopes.
Telescopes from the Ground Up

The next clip is from Orion (a telescope company) talking about how a telescope works.

This clip talks about the aperture of a telescope.

This clip talks about the focal length and focal ratio when buying a telescope.

The Value of Space Exploration

While this video is old, it does a pretty good job outlining some key facts relating to the value of space exploration.

What is space exploration doing for you?

Included at the link below is a NASA Symposium on the value of space exploration hosted by the National Geographic Society.
The Value of Space Exploration (A National Geographic Society symposium)