NASA Officially Cautious About 'Planet Nine' | Video

The space agency is taking a ‘wait and see’ stance on indications of a ninth planet in our solar system (announced Jan. 21st, 2016). Planetary Science Division Director Jim Green says its based on "limited observations,” but has started an important debate that might lead to discovery. -- 'Planet Nine' May Exist: New Evidence for Another World in Our Solar System: Credit: NASA