By Melissa Sevigny, Arizona Science Desk
An astronomer at Northern Arizona University this week announced the discovery of three new objects at the far edge of the solar system, helping narrow the search for the hypothetical "Planet Nine."
The objects were found by NAU astronomer Chad Trujillo and his colleagues. They run the world’s largest survey for “extreme objects” that orbit the sun beyond the Kuiper Belt.
"We've been looking for all kinds of things on the outer edge, but it’s only been in the last year or two where we’ve really started to notice that some of these extreme objects seem to be pointing to the possibility of something big out there," Trujillo said.
Planet Nine is thought to be a massive ice giant lurking beyond Neptune. Trujillo and colleague Scott Sheppard proposed its existence in 2014. Earlier this year, two Caltech astronomers strengthened the case for Planet Nine based on the strange orbits of a cluster of space rocks.
Two of the new objects also have odd orbital alignments. That implies they’re influenced by the undiscovered planet. Trujillo said finding more objects like these will speed up the search.