Arrokoth
Arrokoth is a small, red, two-lobed Kuiper Belt object visited by New Horizons in 2019, the most distant body ever explored up close.
Arrokoth, catalogued as 486958, is a Kuiper Belt object about 36 kilometres long. NASA's New Horizons spacecraft flew past it on 1 January 2019, about 6.6 billion kilometres from the Sun, making it the most distant object ever explored up close. Its name comes from a word meaning 'sky' in the Powhatan and Algonquian languages.
Arrokoth is a contact binary of two flattened lobes, joined at a narrow neck. The join is smooth and undamaged, which shows the two lobes came together at very low speed, probably just a few metres per second or less. It is deep red, coloured by organic compounds, and has few craters.
These features suggest that Arrokoth formed directly from the gentle collapse of a cloud of pebbles in the young disc, a process called streaming instability. It is thought to be almost unchanged since the Solar System's birth, a pristine time capsule from the outer disc.
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