Space is a crazy land, and we are learning something new about it every day: new planets, solar systems, and even the occasional loss of planet.
Growing up, we all had Pluto in our hearts, in our science books, and in our favorite mnemonic device: My Very Educated Mother Just Served Us Nine Pizzas. When news arrived that Pluto had been demoted from planet status, most millennials were heartbroken. Without Pluto, there is no "P," and thus no more pizza. With the loss of Pluto we also lost nine pizzas.
Dr. Brown, in 2005, discovered a 2,236 km-wide object known as Eris in the Kuiper Belt, the same area that Pluto hung out in. It was the discovery of Eris, and the belief that Pluto was slightly smaller, that led to Pluto's infamous demotion to dwarf or mini planet. Because size does matter. Dr. Brown's discovery led to a lot of backlash from those who and grown up with Pluto. But Dr. Brown embraced his haters and his twitter handle is now @PlutoKiller.
Later, scientists would release pictures of our beloved Pluto that showed a cute little heart on the planet and also proved that Pluto is also slightly bigger than Eris, but still too small to sit at the grown-up planet table.
Now scientists claim there is another planet beyond the Kuiper Belt. No one has seen this planet yet, but its existence is believed because of the orbits of certain objects in the Kuiper Belt in our solar system.
This replacement "Planet Nine" is thought to be in between the size of Earth and Neptune. Planet Nine is supposed to be 10 times the size of Earth -- sort of like a "super Earth." Planets of similar sizes appear in other solar systems, but we haven't found one in our solar system yet. For this reason Dr. Brown and Dr. Ellen Stofan, NASA's chief scientist, believe that a ninth planet may be out there. But we still need to see it to believe it, so the hunt is on.
Because we haven't been formally introduced to this Planet Nine, it's hard to say if this guy can fill Pluto's shoes. Maybe if scientists find him and give him a another "P" name, we can get our pizzas back. But even pizza can't replace the love we will always have for Pluto and his big heart.