More than two years after New Horizons flew past Pluto, becoming the first human-made object to visit the dwarf planet, numerous surface features discovered and explored by the craft now have official names as recognized by the International Astronomical Union. Meanwhile, New Horizons itself is preparing for its 1 January 2019 encounter with 2014 MU69, a distant Kuiper Belt Object – all while its control teams search for potential additional flyby targets after the MU69 encounter.
Pluto surface features receive official names:
When New Horizons made its historic flyby of Pluto on 14 July 2015, the return of spectacular images and awe inspiring landscapes immediately inspired the New Horizons team to assign names to the various regions of the dwarf planet.
As with all things in astronomy and official naming practices for celestial bodies inside the solar system, the names given to these various regions were not official.
Only the International Astronomical Union (IAU) holds the ability to officially name moons, planets, dwarf planets, asteroids, and their associated surface features.
After more than two years, on 7 September 2017, the IAU officially recognized the first set of Pluto feature names, including one named after Pluto’s discoverer, Clyde Tombaugh, and another named after Venetia Burney, the British schoolgirl who proposed the name for what ultimately became known as Pluto.
As such, Tombaugh Regio and Burney crater are among the first set of official Pluto feature names – even though the New Horizons science team had been using these and other place names informally to describe the many regions, mountain ranges, plains, valleys and craters discovered during the first close-up look at the surfaces of Pluto and its largest moon, Charon.
In all, the IAU now officially recognizes 14 Pluto feature and place names.
“The approved designations honor many people and space missions who paved the way for the historic exploration of Pluto and the Kuiper Belt, the farthest worlds ever explored,” said Alan Stern, New Horizons principal investigator.
Rita Schulz, chair of the IAU Working Group for Planetary System Nomenclature stated in the announcement, “We’re very excited to approve names recognizing people of significance to Pluto and the pursuit of exploration as well as the mythology of the underworld. These names highlight the importance of pushing to the frontiers of discovery.”
Following on Venetia Burney’s original suggestion, several official place names on Pluto come from underworld mythology… while others honor pioneering space missions, historic pioneers who crossed new horizons in exploration, and scientists and engineers associated with Pluto and the Kuiper Belt.
The first 14 official names of Pluto surface features:
Tombaugh Regio: honors Clyde Tombaugh (1906-1997), the U.S. astronomer who discovered Pluto in 1930 from Lowell Observatory in Arizona.
Burney crater: Venetia Burney (1918-2009), the 11-year-old schoolgirl who first suggested the name “Pluto” for Clyde Tombaugh’s newly discovered planet and later in life taught mathematics and economics.
Sputnik Planitia: a large plain named for Sputnik 1, the first artificial satellite that was launched by the Soviet Union on 4 October 1957.
Tenzing Montes and Hillary Montes: mountain ranges honoring Tenzing Norgay (1914-1986) and Sir Edmund Hillary (1919-2008), the Indian/Nepali Sherpa and New Zealand mountaineer, respectively, who were the first to reach the summit of Mount Everest and return safely.
Adlivun Cavus: a deep depression named for Adlivun, the underworld in Inuit mythology.
Al-Idrisi Montes: honors Ash-Sharif al-Idrisi (1100–1165/66), 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: 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.
Voyager Terra: honors the pair of NASA spacecraft launched in 1977 that performed the “grand tour” of all four giant planets of the solar system and are now exploring interstellar space (Voyager 1 — the first human-made object to leave the solar system) and the boundary between the Sun and interstellar space (Voyager 2).
Virgil Fossae: honors Virgil, one of the great Roman poets and Dante’s fictional guide through hell and purgatory in the Divine Comedy.
Sleipnir Fossa: named for the powerful, eight-legged horse of Norse mythology that carried the god Odin into the underworld.
Hayabusa Terra: a large land mass named in honor of the Japanese spacecraft and mission that performed the first asteroid sample return.
Tartarus Dorsa: 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.
While these are the only 14 recognized feature names on Pluto at present, the New Horizons science team plans to submit more names for official acknowledgement soon.
New Horizons awakens from slumber, teams eye potential post-MU69 flyby targets:
As Pluto’s surface features discovered by New Horizons received their official names, New Horizons’ team was busy finalizing the spacecraft’s trajectory for its New Year’s Day 2019 close encounter with 2014 MU69 – a distant Kuiper Belt Object (KBO) located 4 billion miles (~ 6.437 billion km) from Earth and over one billion miles (~1.609 billion km) farther from the Sun than Pluto.
When New Horizons flies past MU69, it will mark the farthest planetary encounter in history, and, if all goes to plan, New Horizons will come within just 2,175 miles (3,500 km) of MU69 at closest approach, which is 5,625 miles (9,052 km) closer than it came to Pluto in 2014.
Under this nominal approach path, New Horizons will fly over MU69’s celestial north.
Currently, MU69 is understood to either be two similarly sized objects orbiting each other very closely or to be a contact binary – meaning two separate bodies are actually touching each other.
As with all encounter plans, the New Horizons team has a backup route for the probe should debris or a small natural satellite be discovered between now and New Year’s 2019.
The backup plan would see New Horizons increase its closest approach distance to 6,000 miles (10,000 kilometers) – still closer than it flew to Pluto.
“I couldn’t be more excited about this encore performance from New Horizons,” said NASA Planetary Science Director Jim Green. “This mission keeps pushing the limits of what’s possible, and I’m looking forward to the images and data of the most distant object any spacecraft has ever explored.”
If the closer approach is executed, the highest-resolution camera on New Horizons, the Long Range Reconnaissance Imager (LORRI) should be able to spot details as small as 230 feet (70 meters) across – compared to nearly 600 feet (183 meters) on Pluto.
“We’re planning to fly closer to MU69 than Pluto to get even higher resolution imagery and other datasets,” said Alan Stern. “The science should be spectacular.”
In crafting New Horizons’ encounter with MU69, the team weighed numerous factors.
“The considerations included what is known about MU69’s size, shape, and the likelihood of hazards near it, the challenges of navigating close to MU69 while obtaining sharp and well-exposed images, and other spacecraft resources and capabilities,” said John Spencer, science team member and flyby planning lead
Using all seven onboard science instruments, New Horizons will obtain extensive geological, geophysical, compositional, and other data on MU69 and will also search for an atmosphere and moons.
“Reaching 2014 MU69 and seeing it as an actual new world will be another historic exploration achievement,” said Helene Winters, the New Horizons project manager from the Johns Hopkins University Applied Physics Laboratory.
“We are truly going where no one has gone before. Our whole team is excited about the challenges and opportunities of a voyage to this faraway frontier.”
As part of the spacecraft’s preparation for the MU69 flyby, New Horizons was awakened from its five-month long summer slumber on 11 September.
Signals confirming New Horizons executed on-board computer commands to exit hibernation reached mission operations at the Johns Hopkins Applied Physics Lab (APL) in Laurel, Maryland, via NASA’s Deep Space Network station in Madrid, Spain, at 12:55 EDT on 11 September.
That day, the spacecraft was confirmed to be in good health and operating normally, with all systems coming back online as expected.
Over the next three days, the mission ops team brought New Horizons into “active” mode and prepared the craft for a series of science-instrument checkouts and data-collection activities that will last until mid-December.
Over the next several weeks, New Horizons – which is more than 3.6 billion miles (5.8 billion kilometers) from Earth – will perform numerous activities.
The spacecraft will train its instruments on numerous distant KBOs, making long-distance observations with LORRI while also continuously measuring the Kuiper Belt’s radiation, dust, and gas environment.
New Horizons’ team will also test the spacecraft’s instruments in preparation for next year’s approach to MU69 and transmit a new suite of fault-protection software – known as autonomy software – to New Horizons’ computer in early October.
Later this year, New Horizons will carry out a course-correction maneuver on 9 December to set its arrival time at MU69.
On 22 December, New Horizons will go back into hibernation, a state it will remain in until 4 June 2018, at which point its team will wake it back up for the last time to begin preparations for the MU69 approach – which will officially begin in August 2018.
But perhaps most exciting is Alan Stern’s comment on 6 September 2017 to NASA’s Outer Planets Assessment Group that his team is already looking for potential flyby targets after MU69.
While no official selection or crop of candidates has been discussed, the comment is in line with the amount of fuel and power New Horizons still has onboard.
At present, New Horizons can remain operational until roughly 2037 – another 20 years.
However, to accomplish a third – or even fourth, according to Stern – flyby of a KBO, New Horizons will require an additional mission extension, possibly more than one.
The current mission extension, for the MU69 flyby, lasts until 2021.
Given that the Voyager missions are in a perpetual, funded mission extension until their RTGs (Radioisotope Thermoelectric Generators) stop supplying enough electrical power to operate the crafts’ science equipment, the odds of New Horizons receiving additional mission extensions (as the only functional probe in the Kuiper Belt) are high.
(Images: NASA – with credit from NASA to Carlos Hernandez and L2 artist Nathan Koga – The full gallery of Nathan’s (Falcon Heavy to Dragon to Starliner, MCT, SLS, Commercial Crew and more) L2 images can be *found here*)