Fragmenting Comet C/2025 K1

This animation steps through the three images from NASA’s Hubble Space Telescope of the fragmenting comet C/2025 K1 (ATLAS), or K1 for short, taken consecutively on Nov. 8, 9, and 10, 2025. Captured by Hubble’s STIS (Space Telescope Imaging Spectrograph) instrument, the sequence shows the progressive disintegration of the comet over the three-day period. This is the first time Hubble has witnessed a comet so early in the process of breaking up. Hubble caught K1 fragmenting into at least four pieces, each with a distinct coma, the fuzzy envelope of gas and dust that surrounds a comet’s icy nucleus. Hubble cleanly resolved the fragments, but from the ground they only appeared at that time as barely distinguishable blobs. Hubble chronicled the sequence of events and showed exactly how the breakup happened.