Help name Pluto’s two tiny moons

Posted by Karri Ferron
on Tuesday, February 12, 2013

Since 2011, scientists have discovered two new moons around Pluto, boringly called P4 and P5. Now you can vote to give them better names to match their larger satellite siblings, Charon, Nix, and Hydra. // NASA/ESA/M. Showalter (SETI Institute)
Pluto might have been “demoted” in 2006 to dwarf-planet status, but that doesn’t mean this Kuiper Belt object is any less important in the eyes of astronomers. In fact, as NASA’s New Horizons continues its 9.5-year trek to reach Pluto in July 2015, the distant world has received even more scrutiny. This extensive study has led to the discovery of two new plutonian moons since 2011, generically called P4 and P5. But those boring monikers won’t last much longer.

The discoverers of Pluto’s two tiniest moons are inviting the public to help select names for these objects that better match those of their larger brethren, Charon, Nix, and Hydra. These three satellites all received names associated with Hades and the underworld: Charon, the ferryman of Hades in Greek mythology; Nix, the Greek goddess of darkness and night (and Charon’s mother); and Hydra, the nine-headed serpent that battled Hercules.

The SETI Institute, which is running the poll for the new moons’ names, and the astronomers behind the discoveries plan to keep this tradition of monikers derived from Greek or Roman mythology. The public currently can vote on 12 names (Acheron, Alecto, Cerberus, Erebus, Eurydice, Hercules, Hypnos, Lethe, Obol, Orpheus, Persephone, and Styx), but the SETI Institute also will allow write-ins. As the group says on the voting page, “If you can make a good case for it, we will add it to the list.”

Voting is open through noon EST February 25, and the winners will be announced after their formal approval by the International Astronomical Union. Vote today at

I personally think one should be Styx, the river most commonly associated with the underworld in pop culture — not that I'm trying to influence the vote. But I do want to know: Which ones are your favorites?

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