sep 23, 1846 - Janus is discovered by Johann Galle
Description:
(Janus was merely a proposed name by Johann Galle. Urbain Le Verrier proposed the name Neptune before wanting to name the planet Le Verrier in October. It wasn't until Friedrich von Struve favored the name Neptune on the 29th of December was the name adopted as such)Added to timeline:
Date:
sep 23, 1846
Now
~ 179 years ago