Rubin Observatory releases record-breaking image of half-million galaxies

Astronomers have obtained their sharpest view yet of the COSMOS field, a heavily studied patch of sky, thanks to the Vera C. Rubin Observatory’s LSST Camera, the largest digital sensor ever built. The 3.2-billion-pixel camera, mounted on the 8.4-meter Simonyi Survey Telescope in Chile, stacked hundreds of individual exposures taken between April 2025 and January 2026, producing a single frame that displays more than 500,000 galaxies and over 50,000 stars.

The image’s clarity stems from the field’s location away from the Milky Way’s dense plane, reducing interference from nearby stars and dust. Funded jointly by the National Science Foundation and the Department of Energy’s Office of Science, this release—dubbed Early Data Preview 2—covers roughly 3,000 square degrees, about one-sixth of the visible Southern Hemisphere. Rubin Observatory director Bob Blum said the data represent only the start of what repeated surveys will reveal, including countless short-lived phenomena like supernovae. The project forms part of the ten-year Legacy Survey of Space and Time, intended to create the most detailed, continuously updated map of the cosmos.