Science! The Search for Planet 9
In 2014, astronomers Chad Trujillo and Scott Sheppard argued for the existence of a planet beyond Neptune, to help explain the orbits of dwarf planets Sedna and 2012 VP. In 2016, astronomers Mike Brown and Konstantin Batygin proposed the existence of a planet of at least 10 Earth masses, to explain the orbits of six trans-Neptunian objects - and determined what its orbit would be.
Planet 9 is on an elongated orbit, which may take as long as 20,000 years to complete. It is believed to be (more likely than not), an early-forming gas giant that was flung outwards by Jupiter, during the birthing of the solar system. As such, it could be a rocky super earth, or a small ice giant like Neptune. If it does exist (and it would be much stranger if it did not), it will likely have picked up a small collection of moons, some of which may be full-on dwarf planets.
All four astronomers are currently cooperating to locate Planet 9. Brown and Batygin have narrowed the search area down to 600-800 square degrees of sky. Further discoveries of other small bodies and distant dwarf planets, will help further constrain the search area.