Asteroid (44) Nysa May Be the First-Known Three-Lobed World

• Asteroid (44) Nysa is potentially the first known "contact trinary" object, composed of three distinct lobes welded together.
• Researchers led by Kate Minker at Lowell Observatory utilized high-resolution adaptive optics from ground-based telescopes to produce spacecraft-quality imagery.
• A newly discovered moon, designated S/2026 (44) 1, provides a critical opportunity to measure the asteroid's density and confirm its internal structure.

Imaging and Morphology

• Observations using the SHARK-VIS instrument on the Large Binocular Telescope and SPHERE/ZIMPOL on the Very Large Telescope revealed two prominent valleys.
• These features are interpreted as "necks," suggesting the asteroid is a contact trinary, similar to how Comet 67P and Arrokoth formed as contact binaries.
• Researchers remain open to the alternative theory that Nysa could be a single, heavily battered body, though such a shape would still be unique in the solar system.

The Role of the Moon

• A satellite approximately 1 kilometer wide was detected orbiting the 75-kilometer primary body at a distance of at least 170 kilometers.
• The discovery was made using high-contrast imaging techniques previously used for exoplanet hunting.
• By tracking the orbit of the satellite, scientists can calculate Nysa’s mass, enabling the determination of its density and distinguishing whether it is a coherent solid or a collection of collision debris.

Broader Implications

• Nysa is an E-type asteroid rich in enstatite, potentially representing primitive building blocks from the inner Solar System.
• Understanding Nysa's formation process provides insights into the early assembly of planets and the history of solar system leftovers.