Did a Rogue Planet Bring Order to Our Solar System?

Astronomers have long wondered how the giant planets in our solar system rearranged themselves from their original clustered positions into their current orbits. New research suggests a rogue planet or brown dwarf may have caused this cosmic reshuffling by flying past our young solar system. Scientists ran 3,000 computer simulations and found that only objects with masses between 3 and 30 times Jupiter's size, passing at around 20 astronomical units from the sun, could create our current planetary arrangement.