This video segment from Swift: Eyes through Time introduces and explains theories of the origin of gamma-ray bursts. [4:11]

This site has lesson plans and activities related to radiation. Activities include measuring radiation with a Geiger counter and observing radiation 'footprints' in a cloud chamber.

Explains how radiation is produced and the characteristics of alpha, beta, and gamma radiation.

This article with embedded videos provides information about three main types of radioactive decay: alpha, beta, and gamma.

This Imagine the Universe site provides an introduction into the multiwavelength universe and astronomy. Site provides graphics, links to a quiz, facts on this topic as well as teacher resources.