NASA’s Lucy spacecraft is set to fly by the approximately three-mile-wide asteroid Donaldjohanson on April 20, 2025. Researchers at the Southwest Research Institute (SwRI) have used modeling to estimate that Donaldjohanson formed around 150 million years ago when a larger parent asteroid broke apart.
The asteroid’s unique shape and spin properties suggest it could be an elongated object with slow rotation, possibly due to thermal torques. The Lucy mission aims to gather data on the asteroid’s geology and cratering history to understand its formation.
Donaldjohanson is part of the Erigone collisional asteroid family, which was created when a larger parent asteroid broke apart in the inner main belt. The family’s origin shares similarities with other near-Earth asteroids Bennu and Ryugu.
The Lucy mission promises to revolutionize our knowledge of humanity’s home world by visiting 11 asteroids over its 12-year mission. Encounters with main belt asteroids like Donaldjohanson provide a close-up view of these bodies, allowing for engineering tests of the spacecraft’s navigation system and insights into planet formation.
As the mission approaches, scientists are eager to uncover unexpected connections between asteroid characteristics and those of Bennu and Ryugu. The Lucy mission will offer independent insights on asteroid formation processes based on its shape, surface geology, and cratering history.
Source: https://phys.org/news/2025-03-asteroid-donaldjohanson-million-years.html