On Cloud Nine

Our solar system may host a ninth planet that is 10 times the mass of the earth and takes up to 20,000 years to orbit the sun in a bizarre, highly elongated path, scientists say.

The object, nicknamed Planet Nine, orbits about 20 times farther from the Sun on average than Neptune. It would take the planet between 10,000 and 20,000 years to make just one full orbit around the Sun, researches said. The researchers in US discovered the planet's existence through mathematical modelling and computer simulations.