English astronomer John C. Adams and French mathematician Urbain J. J. Leverrier both determined Neptune’s location mathematically, though they were completely unaware of each other’s work at the time. Using Leverrier’s numbers, Johann Galle pinpointed this blue planet through a telescope at the Berlin Observatory in 1846.
However, Galle may not have been the first person to observe Neptune. Judging from Galileo’s notes and drawings, it is believed that the early Italian scientist viewed the planet through his primitive telescope and believed it to be a star.
