Overview
- 3I/ATLAS is in solar conjunction and will reach perihelion on October 29, limiting Earth-based viewing during the most active phase.
- An arXiv analysis by Samuel Grant and Geraint Jones identifies a window from October 30 to November 6 when Europa Clipper could traverse packets of the comet’s ion tail.
- Europa Clipper carries plasma and magnetometer instruments suited to detect cometary ions or magnetic draping, whereas ESA’s Hera, which has a separate October 25–November 1 window, lacks dedicated ion detectors.
- Models indicate both spacecraft would pass millions of kilometers from the tail’s central axis, with detection prospects highly sensitive to real-time solar-wind flow and instrument activation status.
- A separate preprint models the sunward anti-tail as CO2-driven ice-grain scattering that evolves into a conventional antisolar tail, consistent with Keck reports of a pronounced anti-tail and cyanide/nickel emissions; agencies and most researchers say 3I/ATLAS is a natural comet that poses no threat to Earth.