An Etymological Dictionary of Astronomy and Astrophysics

A → trans-Neptunian object located in the → Kuiper belt, nicknamed Ultima Thule. It is elongated in shape with estimated dimensions of about 31 by 19 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.

At a heliocentric distance of 44 → astronomical units, (486958) 2014 MU₆₉ 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: → asteroid designation.