World of Science contains budding encyclopedias of astronomy, scientific biography, chemistry, and physics. This resource has been assembled over more than a decade by internet encyclopedist Eric Weisstein with assistance from the internet community. MeFi visited Weisstein's Mathworld a couple years ago.
Star Viewer ― merging Google Earth (Sky) with Hubblecast videos to learn more about what you're seeing in the night sky. [more inside]