Overview
- Hubble was retargeted to C/2025 K1 as a last‑minute replacement, resulting in an unplanned catch of its breakup that the Auburn‑led team has now detailed in Icarus.
- Three snapshots taken November 8–10, 2025 show at least four to five fragments, including a smaller piece that split again during the observations.
- Researchers estimate the fragmentation began about eight days earlier shortly after perihelion, when the comet passed inside Mercury’s orbit.
- The team reports a one‑to‑three‑day delay in fragment brightening from freshly exposed ice, pointing to thermal lag and dust processes that control outgassing.
- Ground and initial analyses indicate unusually low carbon content; the authors note a possible extrasolar origin, which remains unconfirmed pending further spectroscopy.