Overview
- 3I/ATLAS will make its closest approach on December 19 at roughly 1.8 AU (about 270 million km), a comfortably distant, nonthreatening pass.
- New Hubble and ESA JUICE NavCam imagery shows a bright coma with indications of both a plasma tail and a fainter dust tail, signaling sustained post‑perihelion activity.
- Atacama Compact Array measurements report methanol at about 8% of the vapor output (~40 kg/s) and detectable hydrogen cyanide at 0.25–0.5 kg/s.
- A 16.16‑hour rhythmic pulse in brightness, attributed to rotating jets, produces repeatable 20–40% variations in the comet’s light curve.
- A preprint by Trigo‑Rodríguez and colleagues proposes a metal‑rich, cryovolcanic interpretation, while minority claims of artificial origin remain disputed as JUICE’s full dataset is expected by late February 2026.