This is a list of planet related discoveries, events, and more that occurred in 2009.
January[]
- January 2: HAT-P-11b is discovered.
- January 10: HD 173416 b is discovered.
- January 14: Stardust makes a flyby of Earth.
- January 28: HD 7924 b is discovered.
February[]
- February 2: COROT-6b is discovered.
- February 3: COROT-7b is discovered.
- February 18: HD 11506 c is discovered and Dawn makes a flyby of Mars.
- February 23: HD 16417 b is discovered.
March[]
- March 3: Aegaeon, a moon of Saturn, is discovered.
- March 7: The Kepler Space Telescope is launched.
- March 20: 42 Draconis b and HD 139357 b are discovered.
April[]
- April 17: HD 96167 b is discovered.
- April 21: Gliese 581 e is discovered.
- April 29: HAT-P-12b is discovered.
June[]
- June 10: BD+14°4559 b, BD+20°2457 b, BD+20°2457 c and HD 240210 b are discovered.
July[]
- Unknown date: Chi Virginis b is discovered.
- July 21: HAT-P-13c is discovered.
- July 26: S/2009 S 1 is discovered.
August[]
- August 3: WASP-16b is discovered.
- August 4: MOA-2008-BLG-310Lb is discovered.
- August 11: HD 147018 b, HD 147018 c, HD 171238 b, HD 204313 b and WASP-17b are discovered.
- August 12: 11 Ursae Minoris b, HD 148427 b, HD 179079 b, HD 30562 b, HD 32518 b and HD 73534 b are discovered.
- August 13: HD 86264 b and HD 87883 b are discovered.
- August 24: COROT-7c is discovered.
- August 27: WASP-18b is discovered.
September[]
- September 29: MESSENGER makes a flyby of Mercury.
October[]
- October 19: BD-08°2823 b, BD-08°2823 c, HD 103197 b, HD 104067 b, HD 125612 c, HD 125612 d, HD 148156 b, HD 156411 b, HD 181720 b, HD 190984 b, HD 215497 b, HD 215497 c, HD 28254 b, HD 290327 b, HD 43197 b HD 44219 b HD 6718 b, HD 8535 b, HD 85390 b, HD 90156 b, HD 9578 b, HIP 5158 b and HIP 70849 b are discovered.
- Unknown time in October: The Phoebe Ring is discovered.
November[]
- November 6: Gamma Leonis b is discovered.
- November 9: Gliese 758 B is discovered.
- November 13: Gliese 179 b, HD 126614 Ab, HD 13931 b and HD 24496 Ab are discovered.
- November 27: 30 Arietis Bb is discovered.
December[]
- December 8: OGLE-2007-BLG-368Lb is discovered.
- December 10: WASP-19b is discovered.
- December 14: 23 Librae c, 61 Virginis b, 61 Virginis c, 61 Virginis d, HD 1461 b, HD 1461 d and HD 1461 e are discovered.
- December 16: DP Leonis b and GJ 1214 b are discovered.
- December 17: Gliese 649 b is discovered.
Unknown date[]
- Gliese 667 Cb is discovered.
- HIP 14810 d is discovered.
Previous Year: 2008
Next Year: 2010