October
- Oct 01 - NASA's 50th Birthday (1958)
- Oct 01 - Mars Reconnaissance Orbiter (MRO), Begins Communications Relay Phase
- Oct 01 - Asteroid 9880 Stegosaurus Closest Approach To Earth (1.175 AU)
- Oct 01 - Asteroid 9770 Discovery Closest Approach To Earth (1.606 AU)
- Oct 02 - Cassini, Orbital Trim Maneuver #165 (OTM-165)
- Oct 02 - Cassini, Distant Flyby of Tethys
- Oct 02 - Asteroid 2002 GM5 Near-Earth Flyby (0.011 AU)
- Oct 03 - Asteroid 16857 Goodall Closest Approach To Earth (1.417 AU)
- Oct 03 - Asteroid 8084 Dallas Closest Approach To Earth (2.549 AU)
- Oct 03 - Asteroid 2246 Bowell Closest Approach To Earth (3.302 AU)
- Oct 04-10 - World Space Week
- Oct 05 - Asteroid 12382 Niagara Falls Closest Approach To Earth (1.767 AU)
- Oct 05-09 - 2008 Joint Annual Meeting: Celebrating the International Year of Planet Earth, Houston, Texas
- Oct 06 - MESSENGER, 2nd Mercury Flyby
- Oct 06 - Cassini, Orbital Trim Maneuver #166 (OTM-166)
- Oct 06 - Comet 187P/LINEAR Perihelion (3.693 AU)
- Oct 06 - Asteroid 164400 (2005 GN59) Near-Earth Flyby (0.052 AU)
- Oct 06 - Asteroid 4701 Milani Closest Approach To EArth (1.353 AU)
- Oct 06-08 - 10th International Workshop on Signal Processing for Space Communications, Rhodes Island, Greece
- Oct 06-10 - 19th Ocean Optics Conference, Barga, Italy
- Oct 07 - Asteroid 2005 TQ45 Near-Earth Flyby (0.044 AU)
- Oct 08 - Ejnar Hertzsprung's 135th Birthday (1873)
- Oct 09 - Cassini, Enceladus Flyby
- Oct 09 - Cassini, Distant Flyby of Telesto & Janus
- Oct 09 - Draconids Meteor Shower Peak
- Oct 09 - Asteroid 1991 Darwin Closest Approach To Earth (1.025 AU)
- Oct 09 - Asteroid 1225 Ariane Closest Approach To Earth (1.248 AU)
- Oct 10 - 25th Anniversary (1983), Venera 15, Venus Orbit Insertion
- Oct 11 - Comet P/2001 CV8 (LINEAR) Perihelion (2.160 AU)
- Oct 11 - 40th Anniversary (1968), Apollo 7 Launch (1st Manned Apollo Mission)
- Oct 11 - Wilhelm Olbers' 250th Birthday (1758)
- Oct 14 - Soyuz TMA-13 Soyuz FG Launch (International Space Station 17S)
- Oct 12 - Cassini, Orbital Trim Maneuver #167 (OTM-167)
- Oct 12 - Comet 172P/Yeung Perihelion (2.240 AU)
- Oct 12 - Asteroid 2007 DM41 Near-Earth Flyby (0.061 AU)
- Oct 12 - Asteroid 29075 (1950 DA) Closest Approach To Earth (1.484 AU)
- Oct 12 - Asteroid 5143 Hercales Closest Approach To Earth (1.988 AU)
- Oct 13 - British Interplanetary Society's 75th Birthday (1933)
- Oct 13-17 - IAU Symposium 258: The Ages of Stars, Baltimore, Maryland
- Oct 14 - Kuiper Belt Object 15760 (1992 QB1) Closest Approach To Earth (40.051 AU)
- Oct 14 - Dwarf Planet 136199 Eris (2003 UB313) Closest Approach To Earth (95.778 AU)
- Oct 14 - 5th Anniversary (2003), Shenzhou V Launch (1st Chinese Manned Space Mission)
- Oct 16 - Cassini, Orbital Trim Maneuver #168 (OTM-168)