Nearly two months ago, NASA’s New Horizons spacecraft made history as it flew by Pluto, giving us a first-hand view of the dynamic system. With only a fraction of the data downlinked so far, the intrepid spacecraft now has its sights set on a new target – a tiny Kuiper Belt Object (KBO), dubbed 2014 MU69. Should NASA approve a mission extension, New Horizons will travel nearly 1.6 billion kilometers (one billion miles) to the remote icy world.
“Even as the New Horizons spacecraft speeds away from Pluto out into the Kuiper Belt, and the data from the exciting encounter with this new world is being streamed back to Earth, we are looking outward to the next destination for this intrepid explorer,” John Grunsfeld, former astronaut and chief of the NASA Science Mission Directorate, said in a statement. “While discussions whether to approve this extended mission will take place in the larger context of the planetary science portfolio, we expect it to be much less expensive than the prime mission while still providing new and exciting science.”
Pluto and its five moons were never the final destination for New Horizons. As part of NASA’s New Frontiers mission, New Horizons' primary objective was to study the diversity of the mysterious outer region of the Solar System known as the Kuiper Belt. Finding the perfect target beyond Pluto was no easy task. Thanks to assistance from the Hubble Space Telescope, five potential candidates reachable with New Horizon's limited fuel supply were selected in 2014, and had since been narrowed down to two.
Potential Target 1 (PT1) – officially named 2014 MU69 – was ultimately selected as the spacecraft’s next target on August 28, last week. PT1 is roughly one percent of Pluto’s size, and spans a mere 45 kilometers (30 miles) in diameter. Despite its diminutive size, PT1 is estimated to be 10 times larger and 1,000 times more massive than your average comet. KBOs, like PT1, are thought to be remnants from the dawn of the Solar System. Receiving little heat from the Sun, these icy worlds are essentially frozen time capsules, virtually unchanged since their formation 4.6 billion years ago.
“2014 MU69 is a great choice because it is just the kind of ancient KBO, formed where it orbits now, that the Decadal Survey desired us to fly by,” New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI) explained in a statement. "Moreover, this KBO costs less fuel to reach [than other candidate targets], leaving more fuel for the flyby, for ancillary science, and greater fuel reserves to protect against the unforeseen.”
The New Horizons team will submit an official proposal for the mission extension in 2016; however, early selection of the target KBO is crucial to the mission’s success and to ensure healthy fuel margins. Starting in late October and continuing into November, the spacecraft will conduct a series of four maneuvers setting its course for 2014 MU69.
“There’s so much that we can learn from close-up spacecraft observations that we’ll never learn from Earth, as the Pluto flyby demonstrated so spectacularly,” added New Horizons science team member John Spencer, also of SwRI, in the statement. “The detailed images and other data that New Horizons could obtain from a KBO flyby will revolutionize our understanding of the Kuiper Belt and KBOs.”
Should the mission extension be approved, and all goes according to plan, New Horizons is expected to reach 2014 MU69 on January 1, 2019.