1998 succeeds 1997 and proceeds 1999. This is a list of Planet related discoveries, events, and more that occurred in 1998.
January[]
- January 7: Lunar Prospector is launched.
- January 11: Lunar Prospector enters the orbit of the Moon.
April[]
- April 26: Cassini-Huygens spacecraft makes it’s first Venus flyby.
June[]
- June 23: Gliese 876 b is discovered.
July[]
- July 6: 14 Herculis b is discovered.
September[]
- September 9: HD 168443 b, HD 187123 b and HD 210277 b are discovered.
November[]
- November 24: Gliese 86 b and HD 217107 b are discovered.
Unknown Date[]
- HD 195019 b is discovered.