- Life Extraterrestrial: Life on Other Planets in the Solar System - Curriculum framework for comparing Earth to other planets with regard to life.
- Search for ET! - Interactive Flash tutorial exploring the possibility of and search for life on other worlds.
- The Planetary Society - A nonprofit organization devoted to the exploration of the solar system and the search for extraterrestrial life.
- The Rise and Fall of Star Faring Civilizations in Our Own Galaxy - Speculation, based on the Drake Equation, regarding the existence and composition of alien civilizations.
