New Horizons researchers initially thought the Kuiper Belt object Utima Thule was a contact binary made up of two generally spherical lobes resembling a snowman (upper image). As it turns out, the larger lobe actually resembles a giant pancake while the smaller lobe looks more like a “dented walnut.” The dashed blue lines indicate uncertainty in the current analysis. Image: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Appearances can be deceiving. Just ask Alan Stern, principal investigator with NASA’s New Horizons mission.
During the recent approach and New Year’s Day flyby of a Kuiper Belt body known as Ultima Thule, New Horizons set back an initial few pictures showing a strange bilobate body, an apparent contact binary shaped somewhat like a snowman. A larger roughly spherical component was dubbed Ultima while the smaller “head,” nicknamed Thule, was attached by a fragile looking neck. Thule also appeared to be roughly spherical.
But subsequent analysis, including images showing Ultima Thule receding as New Horizons flew past at more than 50,000 kilometres per hour (31,000 mph), showed the the two lobes are not spherical after all. The larger component resembles a giant pancake-like body while the smaller lobe looks more like a ...