Nysa Reveals a Trilobate Asteroid, Challenging the Two-Lobe Rule
New ground-based images from SHARK-VIS and SPHERE/ZIMPOL show asteroid (44) Nysa has three connected lobes with two necks and a newly discovered moon, S/2026 (44) 1. This trilobate shape shatters the long-standing pattern of two-lobed contact binaries and prompts two competing formation scenarios—a low-velocity reassembly into a contact trilobate or a single parent body reshaped by a hit-and-run collision. Distinguishing between them will require internal density/composition data beyond shape alone; the finding also suggests we may need to re-examine other two-lobed asteroids for hidden features.
