An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

Beyond Neptune lies the Kuiper Belt, a vast expanse of icy bodies that may hold clues to the solar system’s formation. These ...

Simpson and Chen ran mathematical models looking at how differently sized Earth-like worlds would have affected the rest of ...

Planet Nine", dubbed, has fascinated scientists for its ability to account for "anomalous" motions of objects located faraway ...