| Arrokoth | |
|---|---|
| |
| Diameter | 30–45 km 20–30 mi. |
| Distance from primary | 172 million km 107 million mi. |
486958 Arrokoth, nicknamed Ultima Thule, is a trans-Neptunian object located in the Kuiper belt. It is a contact binary 31 km long, composed of two joined bodies 19 km and 14 km across that are nicknamed "Ultima" and "Thule", respectively.
The New Horizons space probe's flyby on 1 January 2019 (UTC time), Arrokoth became the farthest object in the Solar System visited by a spacecraft, and is believed to be the most primitive, both bodies being planetesimal aggregates of much smaller building blocks.