Interstellar Comet 3I/ATLAS: Origin, Trajectory and Scientific Stakes In 2025’s Third‑Ever Extrasolar Visitor
<li ATLAS imaged the interstellar candidate on 1 July 2025, with precovery back to 14 June 2025, and it was designated C/2025 N1 (ATLAS) and later 3I/ATLAS as the third confirmed interstellar object after Oumuamua and Borisov. <li A JPL orbital solution yields eccentricity e = 6.1 ± 0.1 and hyperbolic excess velocity V∞ ≈ 58 km/s, indicating an extrasolar origin from Galactic longitude about 5° toward the Galactic Center. <li The object’s nucleus is estimated at 9–20 km in diameter, with a developing coma and tail already visible, including a compact coma at about 4.5 AU from the Sun.