Depending on which belief you subscribe to, there are currently 8 planets in our solar system. We were taught that there were 9 back in the day, but in recent years scientists seem to think that due to Pluto’s size that it does not constitute as a “real” planet (a dwarf planet, to be exact), but we guess that’s a debate for another day.
That being said, recently astronomers at the California Institute of Technology claim that they might have discovered the ninth planet in our solar system, one that exists beyond Pluto, and one that they believe satisfies their definition of a planet. Now we say that they “might” have discovered the planet because they have not actually found the planet itself.
Instead, what they have discovered are a half-dozen small bodies in distant elliptical orbits, all of which are tilted at the same angle, leading them to believe that a ninth planet could be herding them. Based on their calculations, they expect that this alleged planet will be as big as Earth, or maybe even bigger.
According to one of the scientists, Dr. Michael E. Brown, “We have pretty good constraints on its orbit. What we don’t know is where it is in its orbit, which is too bad.” The planet is estimated to be 20-100 billion miles away, and would take 10,000-20,000 years just to orbit the sun.