See how the human heart moves blood through the body in this animated feature from the NOVA: "Cut to the Heart" Web site.

NASA site explores what a comet's nucleus is composed of. Animation and photographs are provided as well.

This interactive site provides animations and activities in several areas of physiology. The images are simple, but clear. The accompanying text provides a good description of the process being shown.

At this site from Encyclopedia Brittanica, Inc. you can follow brave-hearted women through a timeline of unbelievable "Herstory." Impressive site tracks the unsinkable American woman from Early American adventurers like Sacagawea and...