W. M. Keck Observatory

The W. M. Keck Observatory operates two telescopes with 10-meter mirrors at 4,145 meters near the summit of Maunakea, Hawaii. Keck I was completed in 1993 and Keck II in 1996; they were the largest optical reflectors in the world at the time. Each primary is a mosaic of 36 hexagonal segments held to about 4 nanometers of surface accuracy by active optics, and both telescopes have laser guide star adaptive optics to cancel atmospheric blur.

Flagship instruments

• NIRC2: near-infrared imaging with adaptive optics.
• KCWI, MOSFIRE, LRIS and DEIMOS: spectrographs for faint galaxies, quasars and stellar motions.
• Keck Planet Finder: a precision radial-velocity spectrograph for exoplanets, first light in 2022.

Recent results

Keck’s best-known result is the 2008 measurement of the Milky Way’s central black hole, which tracked stars from 1995 to 2007 and found about 4 million solar masses; it fed into the 2020 Nobel Prize. In 2008 Keck and Gemini also took the first image of a multi-planet system, HR 8799.

The archive keeps paying off. In 2026 a team recovered Elias 2-24 b, the youngest exoplanet known, from 2018 NIRC2 data. KCWI showed that DF9 is a third galaxy that appears to lack dark matter, and Keck confirmed 21 of Euclid’s most distant quasar candidates, setting a redshift record of 7.77.

What to watch, 2026-2030

Our sources list no major dated milestones for Keck itself. Watch instead how its spectrographs keep up with the survey era: Euclid’s data releases and the Rubin Observatory alert stream will produce far more candidates than any single telescope can follow up.

Why scientists are converging here

Large surveys find objects; Keck tells you what they are. That follow-up role, plus adaptive optics sharp enough for black hole orbits and young exoplanets, keeps Keck in heavy demand. Its neighbor on Maunakea is the Subaru Telescope.