In the outer reaches of the Solar System, beyond the ice giant Neptune, lies a ring of comets and dwarf planets known as the Kuiper Belt. The closest of these objects are billions of kilometers away.

Out beyond the orbit of Neptune lies an expansive ring of ancient relics, dynamical enigmas, and possibly a hidden planet—or two. The Kuiper Belt, a region of frozen debris about 30 to 50 times ...

As next-generation telescopes map this outer frontier, astronomers are bracing for discoveries that could reveal hidden planets, strange structures, and clues to the solar system’s chaotic youth. Out ...

Astronomers at Princeton University have uncovered evidence that the outer solar system is more structured than long believed. Led by astrophysics doctoral student Amir Siraj, the research points to a ...