Astronomers are looking for names for two newly discovered moons of Pluto. The moons are currently called P4 and P5, and are the fourth and fifth moons of the former planet (RIP planetary status), after Charon, Nix and Hydra.
P4, also known as S/2011 (134340) 1, was discovered in June 2011 by the Hubble Space Telescope and has a diameter between 8 and 21 miles. P5, also known as S/2012 (134340) 1, was also identified using Hubble, in July 2012, and has a diameter between 6 and 16 miles.
P4 is the second furthest moon from Pluto, with an approximate orbital radius of 37,000 miles and P5 is Pluto's second closest moon, with an orbital radius of about 26,000 miles.
P4 and P5 were both discovered by a team from the Carl Sagan Center for the Study of Life in the Universe at the Searching for Extraterrestrial Intelligence (SETI) Institute in Mountain View, California, led by Mark Showalter.
SETI announced on Monday that the new moons' names would be decided by the public. The institute has already drafted a list of mythological names, and write-ins are encouraged. The list includes Acheron, Alecto, Cerberus, Erebus, Eurydice, Hercules, Hypnos, Lethe, Obol, Orpheus, Persephone, Styx and Vulcan.
Highlights of the list include Obol, the fare for the boat to the underworld; Alecto, Hades' servant who punished mortals for crimes of anger; and Acheron, the river of pain.
"The Greeks were great storytellers, and they have given us a colorful cast of characters to work with," said Showalter.
An online ballot and a list of the names can be found at PlutoRocks.com. As of the running tally on the website, Styx, the river through the underworld, is just ahead of Cerebus, Hades' three-headed dog.
Voting ends on Monday, February 25th, 2013, when SETI will propose the winning names to the International Astronomical Union (IAU).