Astronomers find interstellar comet 3I/ATLAS hiding in images taken before its official discovery

Astronomers have discovered images of interstellar comet 3I/ATLAS taken before its official discovery, with the Rubin Observatory capturing images between June 21 and July 2, 2025. The comet was also seen by the Rubin Observatory on July 3, 2025. This finding provides new insights into the comet's trajectory and composition.