An Etymological Dictionary of Astronomy and Astrophysics

A → trans-Neptunian object located in the → Kuiper belt; provisional designation 2014 MU₆₉ and nicknamed Ultima Thule.

Its overall dimensions are about

36 × 18 × 10 km. NASA’s → New Horizons spacecraft conducted a close → flyby of the object on January 1, 2019 just 3,500 km above the object’s surface. The images it took show that the object has in fact two distinct lobes.

The individual lobes have approximate dimensions of 21 × 20 × 9 km and 15 × 14 × 10 km, respectively.

At a → heliocentric distance of 44 → astronomical units, 486958 Arrokth is the most distant object ever visited by a spacecraft.

It has an → orbital period of 298 years, a small → inclination (~ 2.45°), and a low → eccentricity (0.042).

See also: Arrokoth is a Native American term meaning “sky” in the Powhatan language of the Tidewater region of Virginia and Maryland; → asteroid designation.