April
- Apr 01 - Cassini, Distant Flyby of Pallene & Janus
- Apr 01 - Asteroid 6154 Stevesynnott Closest Approach To Earth (1.449 AU)
- Apr 01-03 - 12th Annual Ground System Architectures Workshop 2008 (GSAW2008), Redondo Beach, California
- Apr 02 - Asteroid 9950 ESA Closest Approach To Earth (2.710 AU)
- Apr 02 - 45th Anniversary (1963), Luna 4 Launch (Soviet Moon Flyby Mission)
- Apr 03 - Asteroid 6135 Billowen Closest Approach To Earth (1.168 AU)
- Apr 03 - Asteroid 4766 Malin Closest Approach To Earth (1.671 AU)
- Apr 04 - Asteroid 2004 VW14 Near-Earth Flyby (0.069 AU)
- Apr 04 - Asteroid 12104 Chesley Closest Approach To Earth (2.016 AU)
- Apr 04 - 40th Anniversary (1968), Apollo 6 Launch (Last Test Flight of Saturn V)
- Apr 05 - Asteroid 1886 Lowell Closest Approach To Earth (1.757 AU)
- Apr 05 - Kuiper Belt Object 136108 (2003 EL61) Closest Approach To Earth (50.229 AU)
- Apr 05 -1st Middle East-Africa Regional IAU Meeting, Cairo, Egypt
- Apr 05 - 35th Anniversary (1973), Pioneer 11 Launch (Jupiter & Saturn Flyby Mission)
- Apr 05-10 - 1st Middle East-Africa, IAU Regional Meeting, Cairo, Egypt
- Apr 06 - Asteroid 1940 Whipple Closest Approach To Earth (2.135 AU)
- Apr 06 - Asteroid 2001 QO142 Near-Earth Flyby (0.088 AU)
- Apr 07 - Asteroid 742 Edisona Closest Approach To Earth (2.346 AU)
- Apr 07 - 40th Anniversary (1968), Luna 14 Launch (Soviet Moon Orbiter Mission)
- Apr 07-11 - Workshop: Transits - Exoplanet and Stellar Astrophysics, Pasadena, California
- Apr 08 - Soyuz TMA-12 Soyuz FG Launch (International Space Station 16S)
- Apr 08 - Asteroid 7359 Messier Closest Approach To Earth (2.607 AU)
- Apr 08-10 - 24th Aerospace Testing Seminar, Manhattan Beach, California
- Apr 08-12 - Conference: Exploring the Solar System and the Universe, Bucharest, Romania
- Apr 09 - Chandrayaan 1 PSLV Launch (India - Lunar Orbiter)
- Apr 09 - Asteroid 1999 SO5 Near-Earth Flyby (0.094 AU)
- Apr 10 - Phoenix, Trajectory Correction Maneuver #3 (TCM-3)
- Apr 10 - Cassini, Orbital Trim Maneuver #152 (OTM-152)
- Apr 10 - Comet C/2007 B2 (Skiff) Closest Approach To Earth (2.287 AU)
- Apr 10 - Asteroid 4783 Wasson Closest Approach To Earth (1.596 AU)
- Apr 11 - Cassini, Distant Flyby of Mimas
- Apr 12 - Comet Brooks 2 Perihelion(1.467 AU)
- Apr 12 - Asteroid 2005 OR2 Near-Earth Flyby (0.094 AU)
- Apr 12 - Asteroid 2041 Lancelot Closest Approach To Earth (2.700 AU)
- Apr 12 - Yuri's Night 2008: World Space Party
- Apr 13 - Asteroid 12426 Racquetball Closest Approach To Earth (1.525 AU)
- Apr 13-18 - European Geosciences Union General Assembly 2008, Vienna, Austria
- Apr 14 - GSTB-V2B (Giove B) Soyuz FG-Fregat Launch
- Apr 14 - Asteroid 4957 Brucemurray Closest Approach To Earth (2.024 AU)
- Apr 14 - Asteroid 13667 Samthurman Closest Approach To Earth (1.786 AU)
- Apr 14 - Lecture: Voyager's Journey to the Edge of Interstellar Space, Boulder, Colorado
- Apr 14-15 - ESA Investment Forum, Noordwijk, The Netherlands
- Apr 14-16 - Trilateral Safety & Mission Assurance Conference (TRISMAC 2008): Lessons Learned for Future Space Missions, Noordwijk, The Netherlands
- Apr 14-16 - An XXL Extragalactic Survey: Prospects for the XMM Next Decade, Paris, France
- Apr 14-18 - Workshop: Astronomy in the Next Decade - Synergies with the Square Kilometre Array, Bonn, Germany
- Apr 14-18 - Conference: A Decade of Accreting Millisecond X-ray Pulsars, Amsterdam, The Netherlands
- Apr 14-19 - 15th Young Scientists' Conference on Astronomy and Space Physics, Kyiv, Ukraine
- Apr 15 - C/NOFS (CINDI) Pegasus XL Launch
- Apr 15 - Asteroid 2004 FG11 Near-Earth Flyby (0.087 AU)
- Apr 15 - Asteroid 5102 Benfranklin Closest Approach To Earth (2.338 AU)
- Apr 15-17 - 2008 Astrobiology Science Conference (AbSciCon 2008), Santa Clara, California
- Apr 16 - GeoEye 1 (Orbview 5) Delta 2 Launch
- Apr 16-18 - 22nd Congreso Nacional de Astronomia, Mexico City, Mexico
- Apr 17 - Space Tracking and Surveillance System (STSS) ATRR Delta 2 Launch
- Apr 17 - Asteroid 2005 NB7 Near-Earth Flyby (0.042 AU)
- Apr 17 - Asteroid 25930 Spielberg Closest Approach To Earth (1.307 AU)
- Apr 17 - Asteroid 15845 Bambi Closest Approach To Earth (1.643 AU)
- Apr 17 - Asteroid 3623 Chaplin Closest Approach To Earth (2.058 AU)
- Apr 17-18 - 4th UC Irvine Center for Cosmology Workshop: Galaxy Formation as Revealed by Cosmic Gas, Irvine, California
- Apr 18 - Asteroid 2266 Tchaikovsky Closest Approach To Earth (2.764 AU)
- Apr 19 - Comet 139P/Vaisala-Oterma Perihelion (3.403 AU)
- Apr 20 - Cassini, Distant Flyby of Mimas, Telesto & Epimetheus