Mount Wilson Observatory

Ground-based · 1904 · San Gabriel Mountains, California

Type: Ground-based
Location: San Gabriel Mountains, California
Altitude (m): 1742
Founded: 1904

Notes

Where Hubble established that the spiral nebulae are other galaxies, and then that they are receding. Arguably the most consequential telescope site in history.

Discoveries [DB]

Andromeda Is a Galaxy The Expansion of the Universe

Referenced by

discovery

Andromeda Is a Galaxy The Expansion of the Universe

Open on the Cosmic Exploration shelf — the interactive card, the filters, and everything alongside it.

From the Observatories database in Notion, last edited 2026-08-15. This page is the row, rendered by the build; nothing on it is written by hand.