The International Astronomical Union, tasked to oversee the naming of celestial objects and their surface features, has just approved a set of naming themes for features on Pluto along with its five moons.

The themes had been proposed by the New Horizons mission of NASA, and emerged from the mission’s Our Pluto naming campaign organized back in 2015 along with the SETI Institute.

The campaign sought public participation in naming the features the spacecraft was anticipated to reveal in its historic July 2015 flyby of Pluto.

Naming Themes Revealed

The revised naming themes were agreed for Pluto and its largest moon, Charon, while the four smaller moons — namely Styx, Nix, Kerberos, and Hydra — will have their name themes unchanged. Some of these continue focusing on the mythology of the underworld, which was ruled by the Roman god Pluto, while others will honor human exploration throughout history.

Themes for Pluto include gods and goddesses, as well as other beings linked to mythology, folklore, and literature. There would also be names for underworld sites from different cultures worldwide, as well as heroes of the underworld, Pluto and the Kuiper Belt scientists and engineers, pioneering space missions, and pioneers in the exploration of Earth, sky, and sea.

For Charon, the themes are focused on fictional space missions and narratives, fictional and mythological ships and space vessels, fictional and mythological explorers and travelers, and artists and authors linked to space exploration, particularly Pluto and the Kuiper Belt.

Themes for the smaller moons’ features include river gods for Styx; deities of the night for Nix; literary, historical, and mythological dogs for Kerberos; and legendary serpents and dragons for Hydra.

New Horizons’ principal investigator Alan Stern applauded the partnership and process between IAU and the mission scientists that resulted in “wonderful, inspiring, and engaging naming themes” for Pluto and its lunar features.

"We look forward to the next step — submitting actual feature names for approval,” the scientist said in a statement.

Make Pluto Great Again?

A new scientific paper also recently suggested that the criteria for defining a planet deserve an overhaul, arguing that the moon and even Pluto should be reclassified as planets.

The paper, titled “A Geophysical Planet Definition,” was penned by a team that included Alan Stern, principal investigator of NASA’s New Horizons mission or the one that made a memorable flyby of Pluto back in July 2015.

The main argument: a celestial body’s geophysics, not just whether it orbits the sun, should determine if it deserves planetary status.

The Conversation noted it didn’t sit well with Stern that in 2006, the IAU adjudged Pluto as a non-planet. By the time New Horizons reached the destination, Pluto was already relegated to “plutoid” or “trans-Uranian dwarf planet” status.

According to the manifesto drawn up by NASA scientists, the moon — along with Europa and Ganymede that orbit Jupiter as well as Titan and Enceladus that orbit Saturn — have planetary features and should be upgraded as part of the entire solar system’s modernization. The same move would see Pluto recovering its earlier designation as a planet.

The July 2015 flyby unmasked Pluto as an unusually active geological body marked by flowing glaciers, ice mountains, cliffs, canyons, and huge nitrogen glaciers.