Study of an Inner Main‑Belt Object
Researchers at the Southwest Research Institute (SwRI) have examined the motion of asteroid Donaldjohanson, located in the inner region of the main asteroid belt. The analysis is based on data collected during a close flyby by NASA's Lucy spacecraft, which was tasked with investigating small bodies throughout the solar system.
Dual Rotation Characteristics
Findings indicate that the asteroid does not rotate in a simple, steady manner. Instead, it performs a combined motion: a full spin around its long axis takes roughly 10.5 Earth days, while a secondary wobble around its horizontal axis—known as precession—occurs over a period of about 26.5 days.
Methodology and Implications
The team analyzed high‑resolution imaging and light‑curve data obtained during the Lucy encounter. By separating the two periodic signals, they were able to determine the asteroid’s orientation and infer aspects of its internal structure. Understanding such rotational behavior aids in assessing the mechanical properties and evolution of small solar‑system bodies.
Publication
The results have been peer‑reviewed and published in the journal Science, adding valuable insight into the complex dynamics that can affect irregularly shaped asteroids.