Astronomers Find 3-Lobed Asteroid Nysa With 1-Kilometer Moon

3 articles · Updated · University of Arizona News · Jul 23

High-resolution observations show main-belt asteroid (44) Nysa has a highly concave, likely three-lobed structure and a newly detected moon, S/2026 (44) 1.
SHARK-VIS on the Large Binocular Telescope and SPHERE/ZIMPOL on the VLT produced the sharpest images yet of Nysa, while photometric data helped researchers build a 3D model supporting three lobes linked by narrow necks.
The moon is estimated at just over 1 kilometer wide and at least 170 kilometers from Nysa, whose diameter is about 75 kilometers.
Researchers say the shape may reflect low-velocity re-accumulation after an ancient collision or a hit-and-run impact, and future tracking of the moon's orbit could pin down Nysa's mass and density.
Because Nysa is a bright E-type asteroid whose composition may preserve material from the inner early solar system, confirming its structure could offer clues to planetary building processes billions of years ago.