Comet C/2025 K1 (ATLAS), discovered in May 2025, fragmented into at least three pieces after a close solar passage on Oct. 8. Telescopes at the Asiago Observatory and the Virtual Telescope Project captured the breakup on Nov. 11–13, showing two similarly bright fragments about 2,000 km apart plus a fainter third piece. Believed to originate in the Kuiper belt, the fragments may contain pristine material from the early solar system. Continued observations will track the fragments and help scientists analyze this rare sample.
Comet C/2025 K1 (ATLAS) Shatters Into Three Pieces After Close Solar Passage
Comet C/2025 K1 (ATLAS), discovered in May 2025, fragmented into at least three pieces after a close solar passage on Oct. 8. Telescopes at the Asiago Observatory and the Virtual Telescope Project captured the breakup on Nov. 11–13, showing two similarly bright fragments about 2,000 km apart plus a fainter third piece. Believed to originate in the Kuiper belt, the fragments may contain pristine material from the early solar system. Continued observations will track the fragments and help scientists analyze this rare sample.
01:00 PM, 11/14/2025Science
Comet C/2025 K1 (ATLAS) Shatters Into Three Pieces After Close Solar Passage
Astronomers have captured dramatic images of comet C/2025 K1 (ATLAS) fragmenting in the nights after Nov. 11, following a destabilizing close approach to the Sun on Oct. 8. Telescopes in Italy and remote observing projects recorded the breakup, revealing a rare opportunity to study primordial material released from a cometary nucleus.
Discovered in May 2025, C/2025 K1 (ATLAS) brightened as it neared the Sun and its volatile ices sublimated to form a bright coma and tail. Although it never reached naked-eye visibility, the comet's Oct. 8 perihelion appears to have compromised the nucleus' structural integrity and set the stage for the November fragmentation.
Observers using the 1.82 m Copernicus telescope at the Asiago Observatory in Italy documented the event on Nov. 11–12. Those images show the nucleus split into at least two similarly bright pieces whose brightness peaks are separated by roughly 2,000 km, with a third smaller, fainter fragment evident nearby.
"From a first quick analysis of the images, we can confirm that there are definitely two fairly similar pieces, whose maximum brightness is separated by about 2,000 km," wrote research astronomer Mazzotta Epifani on the Italian National Institute for Astrophysics website. "We suspect the presence of a third, smaller and fainter fragment to the left of the pair."
Gianluca Masi of the Virtual Telescope Project also recorded the breakup on Nov. 12–13, creating an animation that traces how the fragments evolved over a 24-hour interval. Masi noted that excellent atmospheric seeing and the high resolution of his instrument helped capture detailed structure as a substantial section of the nucleus detached from the sunward portion.
Scientists believe C/2025 K1 (ATLAS) likely originated in the Kuiper belt, a distant reservoir of icy bodies beyond Neptune. If this was the comet's first passage into the inner solar system, the fragments could contain relatively unaltered, primordial material — a valuable time capsule for understanding the composition of the early solar nebula.
Note that C/2025 K1 (ATLAS) is not related to the interstellar object 3I/ATLAS; the shared name reflects discovery by the Asteroid Terrestrial-impact Last Alert System (ATLAS) survey, not a physical connection.
Follow-up observations will refine the fragments' trajectories and determine whether any substantial pieces remain intact. For observers and astrophotographers interested in capturing distant comets, consider consulting guides on telescopes, cameras and lenses optimized for comet imaging.
Editor's note: If you'd like to share comet photos with Space.com readers, send your images, comments, and your name and location to spacephotos@space.com.