Pluto will always be in our hearts, that’s for sure, but there are some rumours floating around about a new ninth planet. In a recent paper, two astronomers said they have evidence for a distant giant planet in the solar system1. Michael Brown, a professor of planetary astronomy at Caltech and one of the authors of the paper, says he is “pretty sure there’s one (planet) out there”1. But don’t feel sorry for Pluto just yet, since we haven’t yet seen this ‘new kid on the block’ with our own eyes (or telescopes).
So how can they say there’s probably a planet out there if we haven’t seen it? The authors of this brilliant paper actually observed six different objects, beyond the solar system’s Kuiper belt, an area similar to an asteroid belt located beyond Neptune’s orbit and full of comets and asteroids. They noticed they all had strange orbits and they were all pointing in roughly the same direction, something that couldn’t be easily explained according to what we know about the solar system. But if we add a planet to the equation, somehow things do work. The gravitational effects of this planet would be consistent with these strange orbits and we should even expect to see other objects orbiting perpendicular to the solar system’s plane. And guess what? They found five objects that describe this exact prediction. They even said the probability of this happening due to chance is merely 0.007%1.
This new planet is probably bigger than our own, has a rocky core and a mass about 10 times that of Earth2. Now we have to point our telescopes towards its orbit to try and find it, the problem is that, even though we know how far way it is, we don’t really know its location. As much as we like the little guy, it seems like Pluto really has its days numbered.
1 – Batygin, Konstantin, and Michael E. Brown. “Evidence for a Distant Giant Planet in the Solar System.” The Astronomical Journal 151.2 (2016): 22.
2 – http://www.nytimes.com/2016/01/21/science/space/ninth-planet-solar-system-beyond-pluto.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=photo-spot-region®ion=top-news&WT.nav=top-news