The Kuiper Belt is a ring of icy bodies beyond Neptune, reaching from about thirty to fifty astronomical units from the Sun. It holds Pluto and most of the known dwarf planets of the outer system, along with hundreds of thousands of smaller objects. It is also the source of most short-period comets. New Horizons flew through it, passing Pluto in 2015 and the small, two-lobed object Arrokoth in 2019, the most distant body ever visited up close.
Astrophysics · Solar System · Kuiper Belt
Beyond Neptune lies a broad ring of icy worlds that no one confirmed until 1992. It reset the definition of a planet, demoted Pluto, and preserved a f...
Astrophysics · Solar System · Comets
Far beyond Pluto and the Kuiper Belt, the solar system may end in a vast spherical cloud of icy bodies reaching nearly a light-year out. We have never...