I grumbled when the  International Astronomical Union erased Pluto from the list of “planets” in our solar system. Memorizing the names of the nine planets seemed simple enough when I was in school. Why make it any easier on today’s kids? Besides, I liked my old neighborhood just fine.

But in retrospect, I have to admit that the decision was right. Otherwise, school kids would now have to memorize the often bizarre names of  quite a few more “planets”. Many of the recently discovered “Trans-Neptunian” objects are very similar to Pluto and  should therefore be in the same class. One of them (“Eris”) is even larger than Pluto and has a moon (“Dysnomia”). Sedna, Makemake (in case you are wondering about the name, scroll to the bottom) and Quaoar are only slightly smaller.

Source: National Geographic. Click to enlarge.

Having lost its “planet” designation, Pluto (now a “dwarf planet”) has gained two more moons, making it three: Charon, Hydra and Nix.

National Geographic just published a brief article on the discovery of 14 new TNOs. Why are these cold worlds important? Because they represent building blocks from the early days of our Solar System, and we are interested in learning how (and from what) it formed. NASA’s New Horizon space probe will help to address this question. It is now about halfway to Pluto’s neighborhood.

PS: Makemake was discovered at Easter. Following tradition and IAU rules, it was given the name of a creator deity. Makemake, the creator of humanity and god of fertility in the mythos of the Rapanui, the native people of Easter Island, was chosen in part to preserve the object’s connection with Easter.

Reinhard Kargl

Journalist and media professional currently based in Los Angeles, California. Focusing on science and technology.