Our Solar System is full of mysteries, but if the inner planets are a puzzle, the boundary between the Solar System and interstellar space is a secondhand puzzle with half the pieces missing.

Despite common assumptions, the disk of our Solar System is warped, and the planets travel around the Sun in slightly eccentric (or oblong) orbits. Scientists now think that a mysterious object ...

Passing Star Nudged Solar System 70,000 Years Ago To figure this out, the team ran several simulations that traced the formation of the Oort cloud and the paths of the individual objects inside it.