Getty Images Mark Garlick / Science Photo Library
It could be that somewhere on the edge of our solar system lurks a big planet, and astronomers are looking for it. Although they have not yet found any direct evidence for the planet, a recent discovery provides even more indirect evidence that the planet actually exists. Astronomers found a small solar system body with a strange orbit, which is said to be explained only by another larger planet hiding somewhere.
For a few years, astronomers have been speculating on a ninth planet, orbiting the sun at great distances and spending the last few years searching for it. They first started the hunt in 2016 after looking at a handful of distant solar system objects and noticing something strange. These objects, all farther away than Pluto, had something in common: they circled the Sun at a certain angle from all inner planets.
The observations indicate that the gravitational influence of another planet changes the orbits of the distant objects. Now further discoveries from a newly discovered planetary object with an odd orbit, called 2015 BP519, support the case for an undiscovered planet Nine. 2015 BP519 orbits at an angle of 54 degrees compared to almost everything in the inner solar system, and the theory is that Planet Nine is responsible.
If Planet Nine exists, it's probably only a matter of time before astronomers find it. It would be difficult, however, because the calculated orbit is so incredibly far away. Planet Nine is probably several times as far away as Pluto, which means that even with our most powerful telescopes there is hardly a point – and it's dark. Add to that the difficulty that we do not know exactly where it should be.
But if it's out there, we'll find it someday.