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What's That On Pluto? Official Names Near for Dwarf Planet Geography

Sputnik Planum
Sputnik Planum on the surface of Pluto — part of Pluto's heart-shaped feature. (Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Pluto's famous heart-shaped feature is on the road to getting an official name, nearly two years after its discovery. "Tombaugh Regio" — nicknamed after the discoverer of Pluto, Clyde Tombaugh — is among dozens of informal names that will likely be submitted to the International Astronomical Union (IAU) under new naming themes for the dwarf planet and its moons.

Pluto and its moons Charon, Nix, Styx, Kerberos and Hydra got a close-up from the New Horizons spacecraft flyby in 2015, revealing many surprises, such as mountain ranges on Pluto. It was the first time Pluto's system was viewed by a spacecraft from up close. As data flowed back to Earth, the New Horizons teams gave informal names to features on Pluto and its moons. 

Simultaneously, the team worked with the IAU — the arbitrator of astronomy names — to figure out the naming process for all of the newly visible features. The IAU announced the revised guidelines Thursday (Feb. 23). The revised naming themes include underworld gods or explorers for Pluto, fictional space exploration vessels for Charon, river gods for Styx and dogs from literature for Kerberos, among others. ['Land; on Pluto in Amazing Color (Video)]

"I'm very happy with both the process and partnership that New Horizons and the IAU undertook that led to wonderful, inspiring and engaging naming themes for surface features on Pluto and its moons," Alan Stern, New Horizons' principal investigator and a researcher at the Southwest Research Institute, said in a statement. "We look forward to the next step — submitting actual feature names for approval."

Some of the new names will come from a database created by the public under the Our Pluto naming campaign, which ran in 2015. At the time, the IAU's working group for planetary system nomenclature offered naming themes for the six worlds in Pluto's system.

"The public responded with overwhelming enthusiasm, suggesting and voting on thousands of names within these categories, as well as proposing names not fitting the approved set of themes," IAU officials said in the same statement.

A timeline for naming the features officially was not released. 

Here is the full list of feature names, quoted from the IAU release:


  • Gods, goddesses and other beings associated with the underworld from mythology, folklore and literature.
  • Names for the underworld and for underworld locales from mythology, folklore and literature.
  • Heroes and other explorers of the underworld.
  • Scientists and engineers associated with Pluto and the Kuiper Belt.
  • Pioneering space missions and spacecraft.
  • Historic pioneers who crossed new horizons in the exploration of the Earth, sea and sky.


  • Destinations and milestones of fictional space and other exploration.
  • Fictional and mythological vessels of space and other exploration.
  • Fictional and mythological voyagers, travelers and explorers.
  • Authors and artists associated with space exploration, especially Pluto and the Kuiper Belt.


  • River gods.


  • Deities of the night.


  • Dogs from literature, mythology and history.


  • Legendary serpents and dragons.

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Elizabeth Howell
Elizabeth Howell is a contributing writer for who is one of the few Canadian journalists to report regularly on space exploration. She is pursuing a Ph.D. part-time in aerospace sciences (University of North Dakota) after completing an M.Sc. (space studies) at the same institution. She also holds a bachelor of journalism degree from Carleton University. Besides writing, Elizabeth teaches communications at the university and community college level. To see her latest projects, follow Elizabeth on Twitter at @HowellSpace.