Interstellar Comet 3I/ATLAS: A Visitor from Beyond the Solar System
3I/ATLAS was first spotted on July 1, 2025 by the ATLAS telescope in Río Hurtado, Chile, and officially designated 3I/2025 A1 (ATLAS), the third confirmed interstellar object after 1I/‘Oumuamua (2017) and 2I/Borisov (2019). It is traveling through the inner solar system at about 60–61 kilometers per second relative to the Sun on a hyperbolic trajectory, with perihelion near the orbit of Mars in late October 2025 (about 1.4 AU). Its closest approach to Earth will be roughly 1.6–1.8 AU (240–270 million kilometers), and it will be behind the Sun from Earth’s perspective at that time, posing no threat. The Hubble