StarChild Question of the Month for December 1999   When were
each of the planets first discovered and who did it?   Solar
system progression from the Sun to Pluto.  Only 3 of the 9
planets in our solar system have official "discoverers" and
"times of discovery". The reason is simple - all of the other
planets are easily seen by the unaided human eye. This means
that humankind has been looking at these objects (whether they
understood what they were or not) since first gazing at the
night sky!  Three planets required good telescopes for their
discovery:  Sir William Herschel Uranus was discovered by Sir
William Herschel in 1781. Herschel was probably the most famous
astronomer of the 18th century. In addition to discovering the
planet Uranus, he also observed and cataloged over 800 double
stars and 2,500 nebulae. He was the first astronomer to
correctly describe the spiral structure of our Milky Way Galaxy.
John Couch Adams Neptune was discovered by John Couch Adams in
1846. Adams was an English astronomer an