Overview
- 3I/ATLAS reaches closest approach to the Sun around 29–30 October at roughly 1.36–1.4 AU, a window of peak outgassing and dust activity.
- Agencies including NASA, IAWN, ESA and the MPC report no impact risk, with Earth remaining about 1.6–1.8 AU away during the closest approach in December.
- JWST spectroscopy finds an unusually high carbon‑dioxide‑to‑water ratio with detections of CO2, H2O and CO, pointing to chemistry unlike many Solar System comets.
- Hubble and Gemini images show vigorous dust emission and a tail that shifted from an early sunward anti‑tail to a more conventional orientation.
- An international astrometry campaign runs 27 November–27 January to tighten the hyperbolic orbit solution as the comet becomes observable again after solar glare in early December.