See also:

• Science: Astronomy: Extrasolar Planets  (39)
• Society: Paranormal: UFOs  (284)

This category in other languages:
	Danish  (6)   Dutch  (14)   French  (22)   German  (31)   Italian  (11)   Russian  (4)   Spanish  (8)

• 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.
• Search for ET! - Interactive Flash tutorial exploring the possibility of and search for life on other worlds.