Comet C/2025 K1 (ATLAS): November 2025

This series of Hubble Space Telescope images of the fragmenting comet C/2025 K1 (ATLAS), or K1 for short, was taken over the course of three consecutive days: November 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 this brief 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 as barely distinguishable blobs.

[Image description: A time sequence of three panels side by side. From left to right, the panels are labeled November 8, 2025; November 9, 2025; and November 10, 2025. This series of images from Hubble of the fragmenting comet C/2025 K1 (ATLAS), or K1 for short. The sequence shows the progressive disintegration of the comet over this brief period. Each panel features several bright, fuzzy, blue, streaking lights in a diagonal line from the upper left to the lower right of a black background. In the first panel, four comet-like objects appear. The largest is the second from the upper left. In the second panel, the largest object has broken into two pieces. In the third panel, the pieces appear to be moving away from each other along the invisible diagonal line.]