But no one has ever come up with a convincing explanation for this peculiar tilt ― until now. In a new study slated for publication in The Astrophysical Journal, three planetary scientists at Caltech in Pasadena, California, contend that the tilt was caused by Planet Nine. Planet Nine is thought to be about 10 times bigger than Earth and about 500 times farther from the sun, according to Space.com. Its orbit is believed to be inclined at an angle of about 30 degrees from the other planets’ orbital plane. This cockeyed orbit means that Planet Nine’s gravitational forces have been tugging on the other planets in a way that has gradually caused their orbital plane to shift.

Source: Huffington Post October 21, 2016 19:52 UTC