January
- Jan 01 - International Year of Astronomy 2009
- Jan 01 - Asteroid 2008 LW16 Near-Earth Flyby (0.076 AU)
- Jan 02 - Asteroid 2 Pallas Occults TYC 7046-00691-1 (11.5 Magnitude Star)
- Jan 02 - Asteroid 2008 WQ63 Near-Earth Flyby (0.067 AU)
- Jan 02 - 5th Anniversary (2004), Stardust, Comet Wild 2 Flyby
- Jan 02 - 50th Anniversary (1959), Luna 1 Launch (1st Moon Flyby)
- Jan 03 - Quadrantids Meteor Shower Peak
- Jan 03 - Asteroid 2560 Siegma Occults HIP 33715 (5.7 Magnitude Star)
- Jan 04 - At Perihelion (0.983 AU From Sun)
- Jan 04 - Asteroid 4013 Ogiria Occults HIP 24512 (6.3 Magnitude Star)
- Jan 04 - Closest Approach To Earth (1.712 AU)
- Jan 04 - Asteroid 1034 Mozartia Closest Approach To Earth (1.743 AU)
- Jan 04 - 5th Anniversary (2004), Mars Exploration Rover A (Spirit), Mars Landing
- Jan 04-08 - 213th Meeting of the American Astronomical Society (AAS), Long Beach, California
- Jan 05 - Comet P/2008 X4 (Christensen) Closest Approach To Earth (0.408 AU)
- Jan 05 - Asteroid 7291 Hyakutake Closest Approach To Earth (1.941 AU)
- Jan 05 - Asteroid 51824 Mikeanderson Closest Approach To Earth (2.255 AU)
- Jan 05 - 40th Anniversary (1969), Venera 5 Launch (USSR Venus Atmospheric Probe)
- Jan 07 - Asteroid 6735 Madhatter Closest Approach To Earth (1.033 AU)
- Jan 07 - Asteroid 51823 Rickhusband Closest Approach To Earth (1.832 AU)
- Jan 07 - Asteroid 1691 Oort Closest Approach To Earth (1.886 AU)
- Jan 08 - Asteroid 5682 Beresford Closest Approach To Earth (1.567 AU)
- Jan 09 - Asteroid 951 Gaspra Occults TYC 0587-00858-1 (15.5 Magnitude Star)
- Jan 10 - 40th Anniversary (1969), Venera 6 Launch (USSR Venus Atmospheric Probe)
- Jan 11 - Telstar 11N Zenit 3SLB Launch
- Jan 11 - Asteroid 5450 Sokrates Closest Approach To Earth (1.486 AU)
- Jan 12 - Asteroid 19578 Kirkdouglas Closest Approach To Earth (1.776 AU)
- Jan 12-16 - Conference: Formation and Evolution of Globular Clusters, Santa Barbara, California
- Jan 12-16 - Conference: Essential Cosmology for the Next Generation, Los Cabos, Mexico
- Jan 13 - Asteroid 91287 Simon-Garfunkel Closest Approach To Earth (1.228 AU)
- Jan 13 - Asteroid 6676 Monet Closest Approach To Earth (1.744 AU)
- Jan 13-16 - 2nd Heidelberg Workshop: High-Energy Gamma-rays and Neutrinos from Extra-Galactic Sources, Heidelberg, Germany
- Jan 14 - Wideband Gapfiller Satellite (WGS-2) F-2 Atlas 5 Launch
- Jan 14 - Stardust, Earth Flyby
- Jan 14 - Venus At Its Greatest EasternElongation (47 Degrees)
- Jan 14 - Asteroid 1224 Fantasia Closest Approach To Earth (1.271 AU)
- Jan 14 - Asteroid 2985 Shakespeare Closest Approach To Earth (1.984 AU)
- Jan 14-15 - ESA Workshop on GNC for Small Body Missions, Noordwijk, The Netherlands
- Jan 14-16 - VII Reunion Anual de la Sociedad Chilena de Astronomia (Sochias), Cepal, Chile
- Jan 15 - Dawn, Trajectory Correction Maneuver #2 (TCM-2)
- Jan 15 - Asteroid 2002 AO11 Near-Earth Flyby (0.020 AU)
- Jan 15-16 - Launch Conference of the International Year of Astronomy, Paris, France
- Jan 16 - Asteroid 5430 Luu Closest Approach To Earth (1.692 AU)
- Jan 17 - Comet 204P/LINEAR-NEAT Closest Approach To Earth (0.990 AU)
- Jan 17 - Comet 29P/Schwassmann-Wachmann Closest Approach To Earth (5.115 AU)
- Jan 17 - Asteroid 2105 Gudy Occults HIP 46511 (5.7 Magnitude Star)
- Jan 17 - Asteroid 136849 (1998 CS1) Near-Earth Flyby (0.029 AU)
- Jan 17 - Asteroid 11055 Honduras Closest Approach To Earth (1.983 AU)
- Jan 17 - Asteroid 9661 Hohmann Closest Approach To Earth (3.536 AU)
- Jan 18 - Comet C/2008 E1 (Catalina)Closest Approach To Earth (4.129 AU)
- Jan 18 - Asteroid 51827 Laurelclark Closest Approach To Earth (1.641 AU)
- Jan 18 - Asteroid 3162 Nostalgia Closest Approach To Earth (1.756 AU)
- Jan 18 - Asteroid 656 Beagle Closest Approach To Earth (1.820 AU)
- Jan 18 - Asteroid 7862 Keikonakamura Closest Approach To Earth (1.848 AU)
- Jan 18-24 - International Heidelberg Conference on Dark Matter in Astro and Particle Physics (DARK 2009), Christchurch, New Zealand
- Jan 19-23 - IAU Symposium 260: The Role of Astronomy in Society and Culture, Paris, France
- Jan 19-23 - Constellation School on Numerical Astrophysics and its Role in Star Formation, Cardiff, United Kingdom
- Jan 20 - Asteroid 24101 Cassini Closest Approach To Earth (1.082 AU)
- Jan 20 - Asteroid 48575 Hawaii Closest Approach To Earth (1.782 AU)
- Jan 20 - Asteroid 886 Washingtonia Closest Approach To Earth (2.599 AU)
- Jan 20-21 - Earth Explorer User Consultation Meeting, Lisbon, Portugal
- Jan 20-22 - 2nd European CubeSat Workshop, Noordwijk, The Netherlands
