In 2006, the International Astronomical Union (IAU) elected to define the term “planet” formally for the first time. This definition excluded Pluto and reclassified it as a member of the new “dwarf planet” category, changing the solar system model we had come to love and bringing the planet total down to eight.
Well ladies and gentleman, boys and girls, we may soon have a ninth planet again! Some may ask the obvious question: “Why haven’t we discovered this planet any sooner?” The reason for this is due to how far away it is; much further from us than is Pluto. The new discovery is so far away that it has yet to complete an orbit around the sun since the end of the last ice age.
Additionally, the planet could be as large as TEN times the size of Earth!! Independent studies have suggested the existence of this planet, however, no one has seen it yet. We may be getting close to observing it, though. As many may recall, last July, the New Horizons spacecraft flew by Pluto and took some fabulous pictures. This shows the increasing abilities science is gathering: We may be closer than we think.
So why do we think there is a planet among the outskirts of the Sun’s grasp? Calculations. The predicted orbit above (in yellow), is thanks to calculations which help to explain the orbits of other bodies shown. Scientist Mike Brown and his colleagues have formulated that there must be some unseen force of gravity around the area. This is due to the way bodies we know of behaving irregularly. Even if we observe the planet soon, it may be a while before we know much about it considering the exponential distance away it may be.
Do not count out the scientists yet, Mike Brown is perhaps the most qualified person for the job. He says he is 90% confident in his discovery, a high rate of confidence in astronomy. And theorist Alessandro Morbidelli was also extremely confident, telling the New York Times: “I would bet money. I would bet 10,000 bucks.”