Pluto's unnamed moons are now 'Styx' and 'Kerberos,' 'Vulcan' deemed too illogical
Well, that sucks. On Tuesday, the International Astronomical Union (IAU) announced the names for P4 and P5, two recently discovered moons orbiting Pluto, and apparently the "logical choice" of naming one of the moons "Vulcan" was...too illogical.
Some months back, SETI put out a poll to get the public's feedback on what the moons should be called, and Vulcan—the name of the fictional planet from Star Trek—was the top pick. The IAU, however, rejected the proposal in part because, according to the organization, "Vulcan does not fit into the underworld mythological scheme" used to name Pluto's moons.
Also, the IAU wants to avoid using the name Vulcan because it was previously used to name a hypothetical-but-nonexistent planet between the Sun and Mercury. In fact, astronomers still use the term "vulcanoid" to describe meteroites that orbit in this region.
Although the IAU decided against the Vulcan name and "continues to stress the importance of having a unified naming procedure following certain rules," it says it will look into ways to allow the general public to have a say in the naming of exoplanets. If you want to learn more about the IAU's naming conventions, take a look at its handy primer, and keep it in mind if you ever have the chance to suggest a name for a celestial object.