Astronomers Discover 'Hidden' Interstellar Comet 3I/ATLAS in Pre-Discovery Archival Images
Summary: Astronomers reviewing archival data from the Vera C. Rubin Observatory have discovered that interstellar comet 3I/ATLAS was actually captured in observations between June 21 and July 2, 2025 — more than a week before its official discovery. The object, which hails from outside our solar system, narrowly avoided being named "3I/Rubin" after the survey telescope coincidentally spotted the visitor before it was formally identified.