Episode 1 of 2

Discovery of Neptune at Berlin

Name: Discovery of Neptune at Berlin
Start: 1846-09-23
End: 1846-09-24
Location: Berlin Observatory

When: 23-24 September 1846
Where: Berlin Observatory
Part of: Neptune discovered at Berlin Observatory; Lassell finds Triton

Galle and d'Arrest observed Neptune on 23 September 1846, confirming Le Verrier's predictions within 1° of the calculated location.

Le Verrier's letter arrived at the Berlin Observatory on 23 September 1846. Galle, assisted by d'Arrest, used the observatory's achromatic refractor to locate the planet. The observation confirmed the existence of a major planet in the direction predicted by Le Verrier, near the Capricorn-Aquarius boundary.

Sources

Discovery of Neptune Wikipedia, revision of 2026-10-04
Urbain Le Verrier Wikipedia, revision of 2026-08-29
Johann Gottfried Galle Wikipedia, revision of 2026-08-29

Machine-drafted from the cited Wikipedia passages and checked by a reviewing model, not by a human editor. Every passage cites the revision it was written from; dates and places follow those passages.