The fourth and fifth moons of Pluto, named for the Greek god of the underworld, are currently known simply as P4 and P5.
Tradition hold the names of Pluto's moons are taken from Greek and Roman mythology and relate to Hades and the underworld; the first three of Pluto's moons discovered are named Charon, discovered in 1978, and Nix and Hydra, both discovered in 2005.
Among the potential names for P4 and P5 are Cerburus, Hercules and Orpheus, NewScientist.com reported Monday.
Mark Showalter of the SETI Institute in Mountain View, Calif., head of the team that discovered the new moon, said write-in votes also would be considered, as long as they follow the naming tradition.
Astronomer Clyde Tombaugh, who first spotted Pluto in 1930, chose the name following the suggestion of an 11-year-old girl named Venetia Burney.
"I like to think that we are doing honor to Tombaugh's legacy by now opening up the naming of Pluto's two tiniest known moons to everyone," Showalter said.
People can vote by visiting http://plutorocks.seti.org.
The final decision on the moons' names will be up to the International Astronomical Union.