Nature shares the wonder of Arrakoth, the object once known as 2014 MU69, in the Kuiper Belt beyond Pluto, the most distant world we’ve studied up close. It was observed by the New Horizons spacecraft in January 2019. Those snapshots and other measurements have finally been analyzed and reveal a strange, red world covered in icy organic molecules:
Scientists with the mission have now published new findings on the rocky object, in Science on 13 February. The studies show that its two lobes are not quite as flat as they appear, and that they probably merged gently in the early days of the Solar System, at least four billion years ago. Arrokoth, which is 36 kilometres long, is extremely red, probably because cosmic rays have blasted its surface to create red organic molecules. Unlike many objects in the outer Solar System, Arrokoth does not have water frozen on its surface, although it does have methanol ice.