Japan's Hayabusa2 spacecraft captures rare contact binary asteroid Torifune

Japan's Hayabusa2 probe flew within about one kilometre of asteroid 162173 Torifune on 5 July, traveling at roughly 17 700 km/h. The close‑up images revealed that the roughly 450‑metre object is not a single asteroid but a “contact binary” formed when two smaller bodies slowly collided millions of years ago, giving it a peanut‑like shape.

Planetary scientists said the find offers valuable clues about the processes that built larger planets. Andy Rivkin of Johns Hopkins University called it “an extremely unusual object,” and Sara Russell of the Natural History Museum in London said it could be “one of the best‑recorded examples of a contact binary asteroid.” Infrared measurements taken during the encounter will be analysed for surface temperature and composition, data that could inform future planetary‑defence strategies. Hayabusa2, which brought back samples from asteroid Ryugu in 2020, is slated for additional Earth fly‑bys in 2027‑28 and aims to reach asteroid 1998 KY26 by 2031.