1. Comet Shoemaker-Levy 9: In 1993, Comet Shoemaker-Levy 9 collided with Jupiter, providing scientists with a rare opportunity to observe the impact of a comet with a planet. The collision produced a series of bright fireballs and left dark scars on Jupiter's atmosphere.
2. Hale-Bopp Comet: Hale-Bopp was a bright comet visible to the naked eye that appeared in the night sky in 1997. It was one of the most widely observed comets in modern history and remained visible for 18 months.
3. Hyakutake Comet: Comet Hyakutake was another bright comet that was visible to the naked eye in 1996. It was known for its long tail and greenish coma.
4. LINEAR Shoemaker: LINEAR Shoemaker was a project that used automated telescopes to search for near-Earth objects. It discovered several comets in the 1990s, including Comet Linear Shoemaker (C/1999 S4) and Comet Linear Shoemaker (C/1999 R1), both of which passed close to Earth.
These cometary events in the 1990s contributed to the scientific study and understanding of comets and their interactions with the Solar System.