export_ofoct.com

[00:00.15] The idea that there might be a so-called Planet X moving in the distant reaches of the Solar System has been debated for more than 100 years.

[00:07.59] It's fallen in and out of vogue.

[00:10.25] The latest claim is based on an analysis of the movements of objects in a band of icy material orbiting more than 3bn miles away known as the Kuiper Belt.

[00:19.54] The only way these alignments can be explained, say the Caltech team, is if an object ten times as massive as the Earth is out there somewhere moving perhaps 20 times as far away as Neptune, the current most distant planet.

[00:32.03] The group hope their research will spark a telescope campaign to try to track it down.

[00:38.14] One reason the claim is being taken so seriously is that it comes from the renowned astronomer Mike Brown.

[00:42.91] It was his discoveries in the outer Solar System that eventually led to Pluto losing its planet status in 2006.