Characters from the popular film version of the Wizard of Oz - has Oz made it to Charon?

When the New Horizons spacecraft made its historic fly-by of Pluto in 2015, it wasn't only Pluto that surprised the scientists. Pluto's large moon Charon also turned out to be complex and interesting. This meant that in addition to names for Pluto's surface features, some were needed for Charon's.

The New Horizons team was using some of the names informally as the data came in, but official names for planetary features need the approval of the International Astronomical Union (IAU). In April 2018 the IAU's Working Group for Planetary System Nomenclature approved a dozen names. Since New Horizons itself represented a great voyage of exploration, names were to be
based on the “literature and mythology of exploration”, specifically,

• Authors and artists associated with space exploration


• Fictional and mythological explorers and vessels


• Milestones or destinations in exploration

The chair of the working group, Rita Schulz said, “I am pleased that the features on Charon have been named with international spirit.”

Here are the official names mapped onto an image of Charon.

A mountain is mons – plural montes.
The mountains were to be named for authors and artists.

(1) Butler Mons. Octavia E. Butler (1947-2006) was an African-American science fiction writer whose work was highly acclaimed. She was the first science fiction writer to receive a prestigious MacArthur Fellowship.

(2) Clarke Montes. Arthur C. Clarke (1917-2008) was a man of many talents: science writer, science fiction writer, futurist, inventor and explorer. He co-wrote with Stanley Kubrick the screen play for the 1968 movie 2001: A Space Odyssey.

(3) Kubrick Mons. The influential American film maker Stanley Kubrick (1928-1999) was a director, producer and screen writer. The movie he made with Clarke was his only science fiction creation, but it is a classic.

A chasma is a deep, elongated, steep-sided depression – plural chasmata.
The chasmata on Charon can be named for vessels from mythology or fiction.

(1) Argo Chasma. The Argo is Jason's ship in ancient Greek mythology. He and his crew sailed it in search of the Golden Fleece.

(2) Caleuche Chasma. The Caleuche is a Chilean ghost ship that sails the seas around Chiloé Island, collecting the dead who then sail on it forever.

(3) Mandjet Chasma. The barge of the ancient Egyptian Sun god Ra was called Mandjet. Ra traveled through the sky on the barge for twelve hours, creating the day with his light. Then as he circled through the underworld, it was night on Earth until he sailed out again onto the eastern horizon.

Charon's craters are named after characters associated with science fiction and fantasy.

Although Charon has numerous craters, only six have official names.

(1) Dorothy Crater. Dorothy Gale is the main character in American author L. Frank Baum's book The Wizard of Oz. She also has a role in Baum's other Oz books.

(2) Nasreddin Crater. The Sufi philosopher and traveler Nasreddin Hodja was born in the 13th century in what's now Turkey. His stories and anecdotes were humorous, but with a point. They were so popular that such tales now exist in their thousands and are found not only in the Middle East, but also in parts of southern Europe and Asia.

(3) Nemo Crater. Nemo was the captain of the submarine Nautilus in Jules Verne's Twenty Thousand Leagues Under the Sea and The Mysterious Island.

(4) Pirx Crater. Pirx the pilot travels between the Earth, the Moon and Mars in a series of science fiction stories by Polish author Stanislaw Lem.

(5) Revati Crater. In the Hindu epic Mahabharata Revati is the daughter of King Kakudmi and consort of the God Balarama, the elder brother of Krishna.

(6) Sadko Crater: Sadko was a musician and merchant from Novgorod who traveled to the bottom of the sea. A popular type of oral epic poem, known as a bylina, tells his story.

Controversial?
Although the New Horizons team has used them informally, none of the following names yet has official approval. Most of them are from popular culture and the IAU is somewhat wary of them. This graphic shows some of the features with informal names.

Maculae
A macula – plural maculae – is a dark area. Mordor is the realm of the Dark Lord in JRR Tolkien's tales, so Mordor Macula is an appropriate name. A second macula is Gallifrey after the home planet of Doctor Who in the BBC television series.

More chasmata
In addition to the officially named chasmata, there are also proposals for Nostromo (the Alien films), Macross (the Macross anime series), Serenity (the Firefly series), and Tardis (Doctor Who's spaceship/timeship).

More craters
Two of the names pending are Lewis Carroll's Alice and Kaguya-Hime, princess of the Moon in Japanese folklore. From the original Star Trek there are: Kirk, Spock, Sulu and Uhura. Representatives of the Star Wars films are Organa (Leia organa), Skywalker and Vader. And Ripley Crater hails the indomitable Ellen Ripley from the Alien films.

Planum and terra
A planum is a plateau, and the only one known on Charon is informally known as Vulcan Planum after Spock's home planet. Interestingly, although Dorothy Crater has been accepted, Oz Terra has yet to be. It's Charon's only highland.