It’s no secret that scientists are incredible, unrepentant geeks, so we really shouldn’t be surprised that the tentative maps for Pluto and Charon read like the most awesome mishmash of exploration history and popular culture to ever grace a planetary system. And every single place holds a story.

The New Horizons science team is busy labelling all interesting features on the dwarf planet Pluto and its supersized moon Charon with unofficial names. While we were delighted when the first few placenames on Pluto were all dark gods, we’re even more thrilled that Charon is being populated by some of our favourite explorers from science fiction.

Pluto: A Land of Nightmares and Brave Souls

Tentative place name map for Pluto as of July 29, 2015. Image credit: NASA/JHUAPL/SwRI


Places on Pluto have dark themes — alternate names for the Underworld, deities or explorers of the Underworld, and any writers, scientists, or engineers associated with Pluto and the Kuiper Belt. Each theme is assigned to a different type of feature.

Space missions and spacecraft are subdivided by where the spacecraft travelled. Earth-orbiting spacecraft claim the plains (planum) and any small knobs or hills (colles). Lunar spacecraft are the namesakes of any elongated markings (linea), while interplanetary spacecraft get the most extensive land masses (terra).


Underworld creatures understandably get the mysterious dark spots (macula) and regions (regio), while alternate names for underworlds or specific locations within the underworld claim ridges (dorsa) and deep-sided depressions (cavus). Any travellers to the underworld collect the long-narrow depressions (fossa).

Scientists and Engineers claim the craters, and the bright regions (regio) of undetermined origin. Historic Explorers get the rest—mountains (montes), steep banks (rupes), and valleys (vallis).

The Darkened Equator: Where Dark Gods Roam

Pluto has a strange, dark band around its equator, all mysterious dark regions and spots named for the denizens of the underworld. Meng-p’o Macula is named for the old lady who ensures that all memories are forgotten before souls are reincarnated out of the Chinese underworld. The dark regions squeezing into the tail of the heart are Cthulhu Regio and Krun Regio. Cthulhu is a winged elder god with face tentacles from the fiction of H.P. Lovecraft, while Krun is a giant flesh-mountain and Overlord of the lowermost level of the Underworld from Mandaean faith. Continuing east, Ala Macula is named for an Ibo goddess of fertility and death from Nigeria. Balrog Macula is the first of many Tolkien tributes, the namesake of an evil, underground creature from the Mines of Moria who threatened Gandalf the Grey. Finally, Vacub-Came and Hun-Came are a pair of death gods from Mayan mythology.

Tombaugh Regio: Mountains of Explorers and Hills of Spacecraft

Detail map of the western lobe of Tombaugh Regio. Image credit: NASA/JHUAPL/SwRI

The most distinctive feature of Pluto is a massive, bright heart. It is Tombaugh Regio, named for Clyde Tombaugh (1906-1997), the astronomer who discovered Pluto. Costeau Rupes are a set of steep banks around the top curve of the heart named for Jacques-Yves Cousteau (1910-1997), the French ocean explorer. The western side of Tombaugh Regio is lined by a series of mountain ranges. From north to south, they are al-Idris Montes, Zheng He Montes, Hillary Montes, and Norgay Montes. Along the interior is Sputnik Planum, an young landscape of oddly-smooth plains.

al-Idris Montes are named for Ash-Sharīf al-Idrīsī (1099-1165), an Arab explorer and mapmaker, and geographical advisor to the King of Sicily. Baré Montes are named for the French botanist Jeanne Baré (1740-1807) who disguised herself as a man in order to circumnavigate the Earth. She was the first to formally identify and describe hundreds of plant species including bougainvillea. Zheng He Montes are the namesake of Zheng He (1371-1433, né Ma He), a Chinese admiral, diplomat, and eunuch who widened the spice trade. He led expeditions to around the Indian Ocean, Red Sea, Persian Gulf, and almost into Mozambique Channel to expand trade with Asia, Africa, and the Middle East.

Hillary and Norgay Montes are a matched set of mountain ranges named for the mountaineering explorers who first summited Mount Everest in 1953. Tenzing Norgay (1914-1986, né Namgyal Wangdi) was a Tibetan who later relocated to Nepal, working as a porter on the first Everest reconnoissance missions, then as a sirdar (organizer of sherpas) for several more failed expeditions until reaching the summit with Hillary on May 29, 1953. Sir Edmund Hillary (1919-2008) was a mountaineer and explorer from New Zealand. He spent his later life advocating for sherpa welfare including building schools, hospitals, and airfields.

Hillary and Norgay preparing to depart on their final, successful climb. Image credit: W.G. Lowe

The largest interior plains of that make up the western lobe of the heart are the Sputnik Planum, named for the the first artificial satellite to circle the Earth. The original space explorer was launched by the Soviet Union in 1957. Five distinct hills have earned name: Coleta de Dados, the first fully-Brazillian satellite; Soyuz (Союз, “Union”), honouring the human space transport vehicle; Astrid, the first Swedish micro-satellites that were dedicated to studying auroras in 1995 and 1998; and Challenger and Columbia for the NASA space shuttles lost in 1986 and 2003.

West of the Heart: Depressions and Craters

Detail of the region west of Tombaugh Regio. Image credit: NASA/JHUAPL/SwRI

The small dark spot northeast of Voyager Terra is Cadejo Macula, named for an evil spirit from Central American folklore. The spirit takes the form of a large, shaggy dog with burning eyes that roams the night. The dog is either white or black — one cadejo protects travellers, the other leads to bad decisions — but either will drive travellers to insanity if they turn their back on the cadejo.

The lighter region to the west of Tombaugh Regio are Lowell Regio, named for astronomer Percival Lowell (1855-1916), initiator of the search for Pluto at his observatory. The three extended land masses are Venera Terra (венера, “Venus”), honouring the pioneering Soviet missions to explore Venus; Viking Terra for the NASA Mars orbiters and landers from 1976 to 1980; and Voyager Terra for the NASA space explorers who did the first flybys of the gas giants and continue now as Interstellar explorers.

Lowell at his titular observatory in 1914.

A series of long, thin depressions separate the regions. Djanggawul Fossae are a split-depression named for a divine trinity of two sisters and a brother in Yolngu culture who came from the island of the dead to create the Australian landscape. (That island, Baralku, has its namesake on Saturn’s moon Titan.) Inanna and Dumuzi Fossa are named for a goddess and her husband: the Sumerian goddess was revived from a journey to the underworld when her husband took her place. Virgil and Beatrice are another matched set, tour guides from Dante’s The Divine Comedy. Virgil was a guide through Inferno and Purgatory, while Beatrice led visitors through Paradise.

Kupe Vallis widens into an actual valley cutting through Voyager Terra. It is named for the 10th century Polynesian explorer who discovered New Zealand, and later became a key character in Maori mythology.

The largest crater in the hemisphere is named for Venetia Burney (1918-2009), the British lady who named Pluto when she was a young girl. She suggested the name to her grandfather Falconer Madan, an Oxford librarian, who passed the name along to Herbert Hall Turner, an astronomer with the Royal Astronomical Society.

Studio portrait of Burney in 1929 around the time she named Pluto. Image credit: J. Weston & Son Photographers

The remaining craters in the region are named for a scattering of scientists and engineers. Jan Oort (1900-1992) is the Dutch astronomer who worked extensively to characterize the Milky Way’s structure and rotation, and theorized that our solar system was surrounded by a vast cloud of comets. K. Edgeworth Crater is named for Kenneth Edgeworth (1880-1972), an Irish astronomer who speculated about the existence of a belt of asteroids and short-period comets in the outer solar system, an idea developed by Gerard P. Kuiper into the Kuiper Belt. James Elliot (1943-2011) was the planetary scientist who used occupation techniques to first discover then study Pluto’s atmosphere. Robert Harrington (1942-2005) co-discovered Pluto’s massive moon Charon with James W. Christy. The final two craters are named for administrators: Henry Brinton (1935-2005) was key to getting early Pluto missions funded through NASA, while Harlan Smith (1924-1991) was the director of the McDonald Observatory responsible for many ground-based studies of the dwarf planet.

East of the Heart: Freckled Craters and Bulging Ridges

Detail of the region east of Tombaugh Regio. Image credit: NASA/JHUAPL/SwRI

The biggest regions east of the heart are the lighter Pioneer and Hayabusa Terra. Pioneer is for the NASA missions that explored the sun, moon, Jupiter, and Saturn between 1958 and 1997, while Hayabusa (はやぶさ, “Peregrine Falcon”) is the Japanese robot who completed a sample return from the asteroid 25143 Itokawa. The top of Hayabusa is framed by Eriksson Rupes, a set of steep banks named for the Icelandic explorer Leif Eriksson (970-1020) who is likely the first European to visit North America.

The Tartarus Dorsa ridges are named for the pit of lost souls from the Underworld of Greek Mytholopgy. The ridges are cut by narrow depressions, the Sleipnir Fossa and Sun Wukong Fossa. Sleipnir is named for the eight-legged horse of Norse mythology who can enter the Underworld yet still return, and who was vital to the adventures of the beloved god Balder. Sun Wukong is a powerful Monkey King who was dragged into the the Chinese Underworld but managed to escape with immortality.

Sleipnir carrying Odin to Hell. Image credit: W.G. Collingwood

North of the heart is dotted with smaller craters: Farinella, Coradini, Safronov, Giclas, Kowal, Pulfrich, Drake, Hollis, and Guest. Each crater is a tribute to exploration and discovery. Paolo Farinella (1953-2000) is an Italian astronomer who advanced theories on small body dynamics, including the tidal evolution of Pluto and Charon. Angioletta Coradini (1946-2011) was an Italian planetary scientist who researched the formation of the solar system including working on Apollo sample returns. Viktor Safronov (1917-1999) is a Russian planetary scientist who developed the theory of planetary accretion, and refined theories on the formation of the Oort cloud. Henry Giclas (1910-2007) was an astronomer with Lowell Observatory who focused on tracking proper motions of stars and discovered several asteroids and comets.

Charles Kowal (1940-2011) was a planetary scientist responsible for for discovering 2060 Chiron, the first Centaur during our earliest observations of the Kuiper Belt. Carl Pulfrich (1858-1927) was a German astronomer who invented the blink comparator, an instrument that rapidly flipped between images to allow the human eye to spot changes.

Tombaugh using a blink comparator in 1938. Image credit: Lowell Observatory

Michael Drake (1946-2011) was involved in a series of high-profile space projects from Cassini, HiRISE, and even the upcoming OSIRIS-Rex asteroid sample return. He was the chair of the Solar System Exploration Committee Solar System Exploration Committee when it recommended a Pluto mission to NASA. Andrew J. Hollis (1947-2005) was British astronomer specializing in asteroids, a skilled visual observer and pioneer of photoelectric photometry who obtained some of the earliest lightcurves for brighter asteroids. Finally, John Guest (1938-2012) was a field volcanologist who argued that lunar craters were impact-generated despite the then-popular theory that they were volcanic in origin. He worked on NASA’s early planetary exploration projects including Mariner 10, Viking, and Magellan.

The Far Side of Pluto: Odd Little Lines

Detail of the region opposite Tombaugh Regio. Image credit: NASA/JHUAPL/SwRI

On the far side of Pluto from the iconic heart is a set of lineaments. Chandrayaan, Luna, and Yutu Linea form a set of elongated markings all named for lunar exploration spacecraft. Chandrayaan (चन्द्रयान, “Moon vehicle”) is named for Indian’s first robotic moon mission in 2008-2009; Luna (луна, “moon”) is a series of fifteen Soviet orbiters and landers from 1959 to 1976; and Yutu (玉兔, “Jade Rabbit”) is the first Chinese lunar rover that explored away from the Chang’e lander in 2014.

Between them and the heart is Simonelli Crater. The only other crater of substantial size on Pluto is named for for Damon Simonelli (1958-2004), a planetary scientist who specialized in the shapes and physical properties of small satellites including theories of Pluto’s interior.

Below the Heart: A Last-Ditch Reach to Horror

Below the heart is a cluster of odd features. The largest is Pandemonium Dorsa, ridges named for the capital of Hell in John Milton’s Paradise Lost, an epic poem.

Detail of the region below Tombaugh Regio. Image credit: NASA/JHUAPL/SwRI

Between it and Norgay Montes are Morgoth Macula, dark spots named for the Satan in Tolkien’s The Silmarillion, and Quidlivun Cavus, a deep-sided depression named for the place on the moon souls ascend to during the afterlife according to Inuit mythology.

Charon: A World of Exploration

Tentative place name map for Charon as of July 29, 2015. Image credit: NASA/JHUAPL/SwRI

Charon is a slightly less ominous destination if you can just get past the massive Mordor Macula. Places on the moon are named for destinations and milestones of fictional exploration, the people that explored those fictional lands, and the vessels that carried them to their mysterious destinations. Again, the types of names are each classified to different types of features, but this time the result is an epic tribute to popular culture and fandoms.

Fictional origins and destinations take all the regions (regio), light or dark, and any weird dark spots (macula). Fictional explorers and travellers nab the craters, and the fictional vessels that carry them get all chasms (chasma). Breaking away from fiction to the content creators themselves, any exploration authors, artists, and directors can be the namesake of mountains (mons).

The most distinctive feature on Charon is a mysteriously dark north pole, named Mordor Regio after the region ruled by the dark lord Sauron in Tolkien’s Lord of the Rings.

New Horizons has only returned images of a small patch of Charon in high enough resolution to definitively pick out features, so nearly all the named locations are in one tight region. The western half of the region of clearer imagery is dominated by Star Wars and Doctor Who, while the central region is an extensive tribute to Star Trek. On the far east boundary of the region of clear imagery is Argo Chasma, a massive chasm named for the ship that carried Jason and the Argonauts on their epic sagas in Greek mythology.

Western Charon: Star Wars, Alien, and Doctor Who

Detail of the western mappable region of Charon. Image credit: NASA/JHUAPL/SwRI

To the north are Organa, Skywalker, and Vader craters, named for Princess Leia Organa, her brother Luke Skywalker, and their father and Darth Vader from George Lucas’ Star Wars. Below the force-wielding cluster is a tribute to Alien, with Ripley Crater cross-cutting Nostromos Chasma. The crater is named for Ellen Ripley, heroine of the 1979 film, while the chasm bares the name of her spaceship.

Nasreddin Crater is a stand-alone namesake landmark, named for Nasreddin Hoca. Hoca is a whimsical character in Middle Easter and eastern European folklore, frequently escribed as riding a donkey backwards as he explores the world.

Doctor Who claims the next patch of Charon, with a large dark spot baring the name of the titular Doctor’s home planet, Gallifrey. The region is cross-cut by a deep chasm, Tardis Chasma, named for his time machine and spaceship. The adjacent Alice Crater is named for the heroine in Lewis Carroll’s surrealistic Alice’s Adventures in Wonderland.

The southernmost near-parallel chasm is Macross Chasma, named for the titular spaceship in a Japanese animation created by Shōji Kawamori. One last crater is even farther south, Nemo Crater named for the submarine captain in Jules Verne’s Twenty Thousand Leagues Under the Sea.

Central Charon: Firefly, Star Trek, and 2001

Detail of the central mappable region of Charon. Image credit: NASA/JHUAPL/SwRI

Serenity Chasma continues the array of semi-parallel chasms, and is a tribute to the spaceship n the Joss Whedon television series Firefly. (Commenter alliterator points out this means we finally know the location of Serenity Valley, location of the ship-naming battle so important in the personal histories of Captain Malcolm Reynolds and his crew.)

The large plateau or high plain Vulcan Planum marks out a region dedicated to Gene Roddenberry’s Star Trek. It is named for the fictional homeworld of the Vulcans, including Mr. Spock. Each crater bares the name of a crew member of the Starship Enterprise from the original series: Captain James T. Kirk, First Officer Mr. Spock, Senior Helmsman Lt. Hikaru Sulu, and Communications Officer Lt. Nyota Uhura. The two mountains in the region are named in tribute to 2001: A Space Odyssey: Arthur C. Clarke (1917-2008), the author, and Stanley Kubrick (1928-1999), the director, who closely collaborated to create the classic.

Southeast of the Vulcan Planum is Butler Mons, a mountain named for Octavia E. Butler (1947-2006), author of the Xenogenesis trilogy where spacefaring humans return to Earth, and Kaguya-hime Crater, named for an infant girl in Japanese folklore who came from the moon and lived among humans before returning home.

All of the informal names on Pluto and Charon fit the approved and accepted naming schemes for each world, and will eventually be submitted to the International Astronomer’s Union for formal adoption. They are also pure, distilled, pop culturey goodness with Cthulhu and Balrog munching on Pluto’s equator and the north pole of Charon engulfed in the vastness of Mordor. Every single location hides a story of people and places being honoured. Keep on keeping on, New Horizons scientists: we love how you’re pushing mixing the boundaries between science and science fiction on the outer bounds of our solar system.

Top image: Detail of informal placename map on Charon. Credits: NASA/JHUAPL/SwRI