Original: Comet Shoemaker-Levy 9 ( SL9 , formally designated D/1993 F2 ) was a comet that broke apart and collided with Jupiter in July of 1994 , providing the first direct observation of an extraterrestrial collision of solar system objects .
Simplified: Comet Shoemaker-Levy 9 ( SL9 , D/1993 F2 ) was a comet that broke apart and smashed into Jupiter in July of 1994 .