It’s been two years since New Horizons captured the first high-resolution image of Pluto. Now the IAU has released official names for some of its surface features.

The International Astronomical Union (IAU) has officially approved the names of 14 geological features on the surface of Pluto. All of these remained devoid of officially-sanctioned monikers two years after the flyby of NASA’s New Horizons spacecraft that obtained high-resolution images of the dwarf planet’s surface for the first time. (The IAU is empowered by the world's astronomers as the the sole naming authority for astronomical objects and its features.)

Pluto's just-approved names belong to four broad themes previously accepted by IAU. The themes are pioneering space missions, historic explorers who crossed new frontiers, scientists and engineers who contributed to our knowledge of Pluto and the Kuiper Belt, and underworld mythology — since the names of Pluto and its five moons already fell in that category.

NASA’s New Horizons team made the naming proposal to the IAU after collecting suggestions from the public during an on-line campaign called Our Pluto. The team also added to the list some of the names they had been used informally during science operations.

Although the IAU has insisted in keeping the naming scheme limited to the approved list of themes, some controversy arose in 2015 when researchers began to use informal names for Pluto’s features in different communications, including research papers. Some of these names, such as Cthulhu Regio, Balrog Macula, or Spock crater, were related to science-fiction and fantasy literature and clearly out of the boundaries of IAU’s traditional themes.

It didn't help that that the New Horizons team, understandably preoccupied with analyzing the results of 2015's historic flyby, took its time before submitting a list of feature names for formal approval — yet freely used informal names in publications and presentations. The situation got a little testy at the IAU's 2015 General Assembly between Alan Stern, principal investigator for New Horizons, and the IAU's Working Group for Planetary System Nomenclature. But the relationship improved after the two groups finally began to meet in August 2016.

The first 14 approved feature names are:

Tombaugh Regio honors Clyde Tombaugh (1906–97), the U.S. astronomer who discovered Pluto in 1930 from Lowell Observatory in Arizona.

Burney crater honors Venetia Burney (1918–2009), who as an 11-year-old schoolgirl suggested the name “Pluto” for Clyde Tombaugh’s newly discovered world. Later in life she taught mathematics and economics.

Sputnik Planitia is a broad, low-lying plain named after Sputnik 1, the first space satellite, launched by the Soviet Union in 1957.

Tenzing Montes and Hillary Montes are mountain ranges honoring Tenzing Norgay (1914–86) and Sir Edmund Hillary (1919–2008), the Indian/Nepali Sherpa and New Zealand mountaineer who were the first to reach the summit of Mount Everest and return safely. (Tenzing Montes, initially called Norgay Montes, was switched because Tenzing is the family surname.)

Al-Idrisi Montes honors Ash-Sharif al-Idrisi (1100–65/66), a noted Arab mapmaker and geographer whose landmark work of medieval geography is sometimes translated as “The Pleasure of Him Who Longs to Cross the Horizons.”

Djanggawul Fossae defines a network of long, narrow depressions named for the Djanggawuls, three ancestral beings in indigenous Australian mythology who traveled between the island of the dead and Australia, creating the landscape and filling it with vegetation.

Sleipnir Fossa is named for the powerful, eight-legged horse of Norse mythology that carried the god Odin into the underworld.

Virgil Fossae honors Virgil, one of the greatest Roman poets and Dante’s fictional guide through hell and purgatory in the Divine Comedy.

Adlivun Cavus is a deep depression named for Adlivun, the underworld in Inuit mythology.

Hayabusa Terra is a large land mass saluting the Japanese spacecraft and mission (2003–10) that returned the first asteroid sample.

Voyager Terra honors the twin NASA spacecraft, launched in 1977, that performed the first “grand tour” of all four giant planets. Voyagers 1 and 2 are now probing the boundary between the Sun and interstellar space.

Tartarus Dorsa is a ridge named for Tartarus, the deepest, darkest pit of the underworld in Greek mythology.

Elliot crater recognizes James Elliot (1943–2011), an MIT researcher who pioneered the use of stellar occultations to study the Solar System — leading to discoveries such as the rings of Uranus and the first detection of Pluto's thin atmosphere.

There is no word regarding when more features will receive official recognition, but space aficionados are closely watching for approval of informal names for features on Charon. Those themes, approved by the IAU's Working Group earlier this year, include fictional characters, destinations, and vessels associated with space exploration. So get ready for craters named Sulu, Vader, and Skywalker.