Interstellar Comet 3I/ATLAS – Third Cosmic Visitor Unveiled, Fast and Enormous
3I/ATLAS, the third recorded interstellar object, was discovered July 1, 2025, by the ATLAS survey in Chile. The comet has a hyperbolic orbit with an eccentricity of about 6.2 and will leave the solar system. It reached perihelion near the Sun on October 29–30, 2025, and will pass closest to Earth at 1.8 AU in December. Estimates put its nucleus at no more than 11 km wide.