New Issue: Orbital Catastrophe Ahead? Read Now

Meet Arrokoth: Ultima Thule, the Most Distant Object Ever Explored, Has a New Name

The small body beyond Pluto visited by NASA's New Horizons spacecraft is now officially known as Arrokoth

A composite color image of the primordial contact binary 2014 MU69, also known as Arrokoth

A composite color image of the primordial contact binary 2014 MU69, also known as Arrokoth, based on data gathered by NASA’s New Horizons during a Jan. 1, 2019 flyby.

Join Our Community of Science Lovers!

Hopefully you weren’t too attached to “2014 MU69,” because the most distant object ever explored has a new name.

The 21-mile-wide (34 kilometers) body visited by NASA’s New Horizons spacecraft on Jan. 1 is now officially known as Arrokoth, a term that means “sky” in the Powhatan/Algonquian language, mission team members announced today (Nov. 12).

“The name ‘Arrokoth’ reflects the inspiration of looking to the skies and wondering about the stars and worlds beyond our own,” New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, Colorado, said in a statement. “That desire to learn is at the heart of the New Horizons mission, and we’re honored to join with the Powhatan community and people of Maryland in this celebration of discovery.”


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Like the Powhatan people, New Horizons has strong ties to Maryland and the greater Chesapeake Bay region. The mission is run by The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. And New Horizons team members discovered Arrokoth using NASA’s Hubble Space Telescope, which is operated by the Space Telescope Science Institute in Baltimore. The scientists also relied heavily on Hubble observations to plan the flybys of both Arrokoth and Pluto. 

The epic Pluto encounter, which took place in July 2015, was the centerpiece of New Horizons’ primary mission. The flyby of Arrokoth was the focus of the probe’s extended mission, and it occurred when New Horizons was about 4 billion miles (6.4 billion kilometers) from Earth. 

Arrokoth, which the New Horizons team nicknamed “Ultima Thule,” is one of many frigid bodies way out in the Kuiper Belt, the solar system’s “third zone” beyond Neptune’s orbit. Small Kuiper Belt objects such as Arrokoth are time capsules of a sort, having existed more or less unchanged for more than 4 billion years, scientists say. (New Horizons found that the much larger Pluto, by contrast, shows signs of relatively recent geological activity.)

“Data from the newly named Arrokoth has given us clues about the formation of planets and our cosmic origins,” New Horizons team member Marc Buie, also of SwRI, said in the same statement. “We believe this ancient body, composed of two distinct lobes that merged into one entity, may harbor answers that contribute to our understanding of the origin of life on Earth.”

According to conventions established by the International Astronomical Union (IAU), the discoverers of a cosmic body have the privilege of naming it. The New Horizons team got the consent of Powhatan tribal representatives before proposing Arrokoth to the IAU, NASA officials said. And Rev. Nick Miles of the Pamunkey Tribe, which was part of the original Powhatan Confederacy, opened the Arrokoth naming ceremony at NASA headquarters today with a traditional Algonquian song. 

“We graciously accept this gift from the Powhatan people,” Lori Glaze, director of NASA’s Planetary Science Division, said in the same statement. 

“Bestowing the name Arrokoth signifies the strength and endurance of the indigenous Algonquian people of the Chesapeake region,” Glaze added. “Their heritage continues to be a guiding light for all who search for meaning and understanding of the origins of the universe and the celestial connection of humanity.”

Copyright 2019 Space.com, a Future company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Mike Wall has been writing for Space.com since 2010. His book about the search for alien life, “Out There,” was published on Nov. 13, 2018. Before becoming a science writer, Michael worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor’s degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz.

More by Mike Wall

SPACE.com is the premier source of space exploration, innovation and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier.

More by SPACE.com

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American

Subscribe