Related: Interstellar comet 3I / ATLAS , captured by NASA's Hubble Space Telescope captured on July 21 2025. (NASA, ESA, David Jewitt (UCLA); Image Processing: Joseph DePasquale (STScI)) When it was first detected on July 1 2025 by the Asteroid Terrestrial Last Alert System (or " ATLAS "), one of the first questions people asked was "but is it aliens?". How do we know 3I / ATLAS , also called comet C/2025 N1 ( ATLAS ), is interstellar ? Will it strike Earth? Can we visit it? Here are all of your questions answered. We report initial observations aimed at the characterization of a third interstellar object . This object , 3I / ATLAS or C/2025 N1 ( ATLAS ), was discovered on 2025 July 1 UT and has an orbital eccentricity of e ∼ 6.1, perihelion of q ∼ 1.36 au, inclination of ∼ 175 , and hyperbolic velocity of V∞ ∼ 58 km s−1. Comet 3I/ATLAS is the third known object from outside our solar system to be discovered passing through our celestial neighborhood. Astronomers have categorized this object as interstellar because of the hyperbolic shape of its orbital path.
