Centauri Dreams incorrectly identified the name of one of the new Plutonian moons yesterday as Nyx. The actual name is Nix, as witness this statement from the International Astronomical Union, quoting Oddbjørn Engvold, general secretary of the organization:
“In Greek mythology, Nyx is the goddess of the night, but since asteroid 3908 already bears the Greek name Nyx, we changed Nyx to its Egyptian equivalent, Nix. Hydra was a nine-headed serpent with poisonous blood that had its den at the entrance to Hades, where Pluto and his wife Persephone entered the Underworld.”
Also on the IAU’s agenda at its General Assembly in Prague in late August is a looming question: what is the proper definition of a planet? Pluto’s planetary status is clearly at stake, as is that of 2003 UB313, the 10th ‘planet’ known unofficially as Xena. The Centauri Dreams take is that anything Pluto-sized and over is a planet, and if we wind up with a Solar System of 35 planets, most of them in the Kuiper Belt, so be it. But those who favor more economical systems may prefer eight planets surrounded by large chunks of debris. The IAU has the call.