Astronomers are hot on the hunt for a giant planet in our outer Solar System. If it actually exists, that is.
While the several dwarf planets seem to point toward this unseen, larger-than-Earth object, it has eluded astronomers thus far. And not all of them take it as a matter of time — several astronomers think that it may just be a sampling bias that may not be as weird as it seems.
Here’s everything you need to know about the possible lost sibling of the solar system, from the basic theory to where it may be located, its orbit, and more.