Skip to content
AsteriaStar
Discovery · 1846 CE

The Prediction and Discovery of Neptune

History of Astronomy

Overview

From tiny irregularities in the orbit of Uranus, Le Verrier (and, independently, John Couch Adams) predicted an unseen planet; Galle found Neptune within a degree of the prediction on 23 September 1846.

Why it matters

A planet discovered 'at the tip of a pen' — a spectacular confirmation of Newtonian gravity.

Credit

Objects & facilities

Bearing on theory

Knowledge connections

Sources & references

The primary and reference sources this topic draws on.

  • BritannicaEncyclopaedia Britannica

    General reference for the history of astronomy, biographies, and cultural context.

  • IAUInternational Astronomical Union

    Official naming, definitions, constellation boundaries, and astronomical nomenclature.