The Kuiper Belt is a vast, icy realm on the fringes of our solar system, beyond the orbit of Neptune. This doughnut-shaped region is filled with millions of leftover objects from the solar system's formation, mostly composed of frozen ices like methane and ammonia. It's a treasure trove of icy worlds, including dwarf planets like Pluto, and is thought to be the source of many short-period comets that zip around the Sun. | The Brain Maze

Out beyond the orbit of Neptune sits a vast frontier: the Kuiper Belt… and scientists are itching to know what's out there. | Space 360