Discoveries on Ultima Thule Continue One Year After Approach of New Horizons Spacecraft

Image credit: NASA/John Hopkins University Applied Physics Laboratory/Southwest Research Institute/ESA

One year ago, the New Horizons spacecraft approached a mysterious object, 486958 Arrokoth, orbiting in the Kuiper Belt, a collection of small objects that revolve around the Sun beyond Neptune. The startling discoveries that the New Horizons team made about this object, nicknamed Ultima Thule, revealed the structure and composition of one of the most primitive and undisturbed relics from the earliest moments of our solar system. On the initial approach on January 1, 2019, high-resolution images revealed Arrokoth as consisting of two connected discs described as having the shape of “lumpy pancakes.” Since then, scientists have been poring over data that continues to be sent back by the New Horizons spacecraft. Analyses of fracture patterns and impact craters revealed that the object was likely made from an amalgamation of smaller icy bodies that coalesced together to form two separate discs. Later the two major discs slowly merged. The lack of bombardment from smaller bodies left Arrokoth very well preserved and able to provide invaluable insight into the formation processes of small bodies in the solar system. READ MORE