Overview
- Solar‑system Comet ATLAS (C/2025 K1) has broken into at least three bright pieces since Nov. 12, with images from Michael Jäger and the Virtual Telescope Project documenting the split.
- C/2025 K1 shows an unusual golden hue likely linked to low levels of diatomic carbon and CN, and is around magnitude 10 in Ursa Major for backyard telescopes.
- Interstellar 3I/ATLAS is now inside roughly 300 million km of Earth and closing by about 2 million km per day, with a safe closest approach projected for Dec. 19 at about 170 million miles.
- NASA released a Nov. 19 trove of multi‑mission images after observations by 12 spacecraft, reiterated the object behaves like a comet, and shared Mars orbiter and other views.
- Indian astronomers observing from Mount Abu Nov. 12–15 reported production rates and behavior consistent with some solar‑system comets, as scientists assess reports of small non‑gravitational acceleration near perihelion.