Neptune

Neptune is a distant planet discovered due to irregularities in Uranus's orbit, which suggested the gravitational influence of another planet. It was observed for the first time in 1846, helped by calculations of its possible location due to these perturbations.
 John Couch Adams, Urbain-Joseph Le Verrier England, France 1846 Neptune

Neptune is a distant planet discovered due to irregularities in Uranus's orbit, which suggested the gravitational influence of another planet. It was observed for the first time in 1846, helped by calculations of its possible location due to these perturbations.