Carnegie Science Observatories

The Carnegie Science Observatories began in 1904 as the Mount Wilson Observatory, part of Carnegie Science (founded in 1902), and are now based in Pasadena, California. Carnegie funded the Hooker 100-inch telescope on Mount Wilson, which Edwin Hubble used to transform cosmology. Today its main observing site is Las Campanas Observatory in Chile, established in 1969. Carnegie Science’s president since November 2024 is the astronomer John Mulchaey.

Flagship instruments

• Magellan Telescopes: twin 6.5-meter telescopes at Las Campanas.
• Giant Magellan Telescope: Carnegie is a partner in the consortium, and Las Campanas is the site of the Giant Magellan Telescope.

Recent results

Carnegie’s place in history rests on Edwin Hubble’s work with the Hooker telescope. In 1923 he found that the universe extends far beyond the Milky Way, and his 1926 classification of galaxies gave astronomers the language they still use. In 1929 he showed that galaxies recede at speeds proportional to their distance, the observational basis of the expanding universe. Decades later, Vera Rubin and Kent Ford, at the Carnegie Institution’s Department of Terrestrial Magnetism, measured the rotation of the Andromeda galaxy in 1970, a key step toward the evidence for dark matter. Our sources do not list specific 2026 Carnegie discoveries.

What to watch, 2026-2030

• 2026-2027: completion of the Giant Magellan Telescope’s NSF Final Design Phase, a prerequisite for federal construction funding.
• The 2030s: GMT expected to be completed at Las Campanas.

Why scientists are converging here

Las Campanas will host the only extremely large telescope the US National Science Foundation has advanced to final design, after NSF backed GMT and not the Thirty Meter Telescope in 2025. For cosmology and galaxies, the institution that measured cosmic expansion is preparing to host the telescope that will study its earliest chapters.