Overview
- NASA’s Swift telescope measured hydroxyl in ultraviolet light from 3I/ATLAS, confirming water-driven outgassing at roughly 40 kilograms per second far from the Sun.
- ESA’s ExoMars Trace Gas Orbiter imaged a diffuse coma during a close pass on October 3 from Mars orbit, independently confirming ongoing activity.
- Deep, co-added TESS precovery images from May 7 to June 1 show no extended coma, supporting a surge or onset of activity in mid to late May near about 6 AU.
- Discovered by the ATLAS survey on July 1, 2025, the object’s hyperbolic trajectory established it as the third confirmed interstellar visitor.
- Perihelion on October 29 and scheduled JUICE observations in November are expected to tighten constraints on its nature, as speculative artificial-origin claims remain unconfirmed.