The Kuiper Belt

Beyond Neptune lies the Kuiper Belt, a vast ring of icy bodies extending from 30 to 50 AU from the Sun. It holds an estimated 100,000 objects larger than 100 km across, including Pluto, Eris, Makemake, and Haumea. These frozen worlds preserve conditions from the solar system's earliest days.

The Kuiper Belt is the source of short-period comets — those that orbit the Sun in less than 200 years. A gravitational nudge from Neptune can send an object inward, where solar heating turns it into a glowing comet.