MAUNAKEA, Hawaii, Oct. 16, 2026 - Astronomers have released extended optical observations tracking the interstellar comet 3I/ATLAS through its closest approach to the Sun, showing sustained active morphology across the perihelion period.

The work combines survey data captured in June and July 2026 by the Vera C. Rubin Observatory's Legacy Survey of Space and Time, with targeted high resolution imaging taken 7 October at the W. M. Keck Observatory.

The observing team first obtained calibrated spectra of the comet using Keck's Low Resolution Imaging Spectrometer on 15 May 2026, building a continuous observation window spanning more than five months for the interstellar visitor.

Impact Insight. Interstellar comets are objects that formed outside our Solar System before being deflected inward on a single unbound pass. Extended tracking across perihelion allows researchers to measure how these visitors respond to solar heating, and to compare their physical composition to native Solar System bodies. For planetary defense, interstellar visitors arrive with little warning, so tracking and characterising them quickly is the same skill needed for any unexpected object.