Ultima Thule is no more. The remote solar system body
visited in January by NASA’s New Horizons spacecraft now
has a proper name: Arrokoth.
The word means “sky” in the language of the Powhatan people,
a Native American tribe indigenous to Maryland. The state is home to New
Horizons mission control at the Johns Hopkins University Applied Physics
Laboratory in Laurel.
“We wanted to honor Maryland as our mission epicenter, and
the idea of using a Native American language from there just bubbled up,” says
Alan Stern, head of the New Horizons mission and a planetary scientist at the
Southwest Research Institute in Boulder, Colo. “Tying it to our mission by
using the word ‘sky’ completed the trifecta.”
NASA announced the name change on November 12, with the
consent of Powhatan tribal elders and the International Astronomical Union, the
organization of astronomers who, in part, oversee celestial naming conventions.
Arrokoth (pronounced AR-uh-koth), a flattened two-lobed body
in the Kuiper Belt of icy worlds beyond Neptune, has been through a couple of
names already. Up until now, its official designation had been 2014 MU69. In
March 2018, the
team landed on the nickname Ultima Thule, a Latin phrase that signifies a
place beyond the known world.
“[Ultima Thule] was, as we said, always a placeholder we
would discard once we did the flyby,” Stern says. That moniker came under almost
immediate criticism after Newsweek noted that the phrase had also
been appropriated by the Nazis as the mythical homeland of the Aryan race.
The New Horizons spacecraft — originally sent to
check out Pluto and its retinue of moons (SN: 7/26/15) — is still
transmitting data from its
January 1 flyby of Arrokoth (SN: 1/2/19) and will continue to do so
for at least another year, Stern says. By then, the team will have begun
hunting for a possible third target, a search they can’t start until Earth gets
to the other side of the sun next summer and New Horizons once again becomes
visible at night to telescopes.