Astronomers using ESO's SPHERE instrument at the Very Large Telescope (VLT) have revealed that the asteroid Hygiea could be classified as a dwarf planet. The object is the fourth largest in the asteroid belt after Ceres, Vesta and Pallas. For the first time, astronomers have observed Hygiea in sufficiently high resolution to study its surface and determine its shape and size. They found that Hygiea is spherical, potentially taking the crown from Ceres as the smallest dwarf planet in the solar system.
Now since Hygiea is large enough to be spherical, that would mean that Vesta and Pallas are also spherical and therefor dwarf planets. And since I don't believe in dwarf planets, it would mean that Ceres, Vesta, Pallas and Hygiea are planets 5 through 8 after Mercury, Venus, Earth, and Mars. Which means that Jupiter is thus the ninth planet. Making planets 10-13 Saturn, Uranus, Neptune, and Pluto. The other planets are Eris, Haumea, and Makemake. Though there may be others.
That makes 16 planets overall, of which half are dainty little things. And 16 is a bitch to memorize, but some folks just have to memorize them. Poor souls.
But keep in mind that you have the rest of the Kuiper belt to deal with as well as the Oort Belt and Cloud. We could have lots more.