A snowman-shaped object in space should not exist because its two halves would have crashed at the wrong angle.
April 20, 2026
Original Paper
Challenge in Arrokoth's single merger to achieve the shape's principal axis configuration
arXiv · 2604.16260
The Takeaway
Arrokoth is a Kuiper Belt object made of two lobes that joined together billions of years ago. Most models assume they gently merged along their longest axes to create its unique shape. This new analysis shows that gravity should have twisted the lobes during their approach, making a perfect alignment nearly impossible. The fact that they are aligned suggests our current theories about how the solar system’s building blocks formed are missing something big. This object is a fossil from the early solar system, and its shape is now a major scientific mystery. Solving this will require a total rethink of how gas and dust clumped together to form planets.
From the abstract
The cold-classical Kuiper Belt Object 486958 Arrokoth is a contact binary composed of two flattened lobes, Weeyo and Wenu, closely aligned along their principal axes, despite each lobe having a highly irregular shape. The object's smooth and relatively undamaged structure suggests the observed bilobate shape results from a gentle, low-velocity merger between the lobes. The existing hypotheses to explain such a merger include orbital energy dissipation from the protosolar nebula gas drag and Lido