 In fact, a great irony to the story is that there was several discoveries of large objects in the solar system that scientists excitedly called planets when they were found. And astronomers would later point to those discoveries when deciding how to differentiate the eight planets we still have today from the other objects in space. The big two are Ceres and Aries. The realization that Ceres exists came first in the early 1800s. It was born out of this search for a planet in between Mars and Jupiter.