Scientists have been trying to find a hypothetical Planet 9 that may exist outside our known solar system based on the unusual orbits of certain dwarf planets. But those orbits might not require a ...

A new study suggests that a close encounter with a massive interstellar object, possibly eight times the mass of Jupiter, may have significantly altered the orbits of the four outer planets in our ...

For centuries, astronomers have sought to understand the formation and evolution of the solar system and the dynamics that govern it. In particular, there is the long-standing question of whether or ...