Comet C/2025 K1 Orbit Illustration

This diagram shows the path the long-period comet C/2025 K1 (ATLAS), or K1 for short, took as it swung past the Sun and began its journey out of the solar system. On Nov. 10, 2025, NASA’s Hubble Space Telescope captured the inset image of the fragmenting comet. Hubble took this image just a month after K1’s closest approach to the Sun, called perihelion. During perihelion, a comet experiences its most intense heating and maximum stress. Just past perihelion is when some long-period comets like K1 tend to fall apart. The comet’s perihelion was inside Mercury’s orbit, about one-third the distance of the Earth from the Sun. This is the first time Hubble has witnessed a comet so early in the process of breaking up.