Evidence of a Ninth Planet Found in Outer Solar System
Caltech researchers have found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer solar system. The object, which the researchers have nicknamed Planet Nine, has a mass about ten times that of Earth and orbits about 20 times farther from the sun on average than does Neptune (which orbits the sun at an average distance of 2.8 billion miles). It would take this new planet between 10,000 and 20,000 years to make just one full orbit around the sun. The researchers discovered the planet's existence through mathematical modeling and computer simulations but have not yet observed the object directly.