3I/ATLAS is the third confirmed interstellar object to visit our Solar System, discovered on 1 July 2025 by the ATLAS survey in Chile. It follows a hyperbolic path with an eccentricity of about 6.1 and an incoming speed of roughly 58 km/s from the direction of Sagittarius — far too fast to be bound to the Sun. This scenario begins on 1 March 2023, when the comet was still inbound at about 33 AU, beyond Neptune. Like 1I/ʻOumuamua and 2I/Borisov before it, 3I/ATLAS carries chemical and isotopic signatures from another star system, offering a rare chance to compare cometary composition across galactic neighbourhoods without travelling the light-years between them.