Lucy observations reveal a tumbling, peanut-shaped asteroid

Analysis of NASA’s Lucy flyby has revealed more about the unusual shape and rotation of asteroid Donaldjohanson.

Lucy passed the asteroid on April 20, 2025, at a distance of roughly 650 miles. Findings released in June 2026 describe a peanut-like body with complex rotational motion, providing clues to the small world’s history.

The researchers connect its development with an ancient collision and subsequent changes influenced by sunlight. The encounter also served as a useful opportunity for Lucy to observe an asteroid at close range before its main investigations of Jupiter’s Trojan asteroids, a population that can preserve evidence of the solar system’s early evolution.