Astronomers have announced a contest to name two moons discovered orbiting Pluto.
P4 and P5, as they are called, were discovered in 2011 and 2012 after photographs taken by the Hubble Space Telescope revealed the unknown moons.
Three Pluto moons already have names associated with Hades and the underworld. They are Charon, the ferryman of Hades; Nix for the night goddess; and the multi-headed monster Hydra.
Researchers have asked members of the public to retain the theme by choosing names from a list of names made famous by Greek and Roman mythology. They’re no more than 20 miles (32 kms) across.
Online voting will last two weeks. Twelve choices are available at the website “plutorocks.” Choices include the hero who slew Hydra, Hercules; and Styx, the river to the underworld. Write-in suggestions are welcomed.