JSCC Subject Directory: Astronomy

NASA: Breaking news; Links to NASA field offices; Research information; Space shuttle information
SparkNotes on Astronomy: Detailed nformation about all nine planets in the solar system.
The Constellations and Their Stars: Information about constellations and stars
Space Telescope Science Institute: Filled with information and pictures from the Hubble Space Telescope.

The Moon

Apollo Lunar Surface Journal: Includes the transcripts of radio messages sent and received during the Apollo moon missions supplemented with astronaut commentary.
SETI Institute Online: Read about the Search for Extraterrestrial Intelligence.
SETI@home: Help the Search for Extraterrestrial Intelligence at home.
Stars (full text): The full text by A.S. Eddington
Mars (full text): The full text by Percival Lowell