Asteroid Donaldjohanson, a small main belt asteroid set to be visited by NASA’s Lucy spacecraft on April 20, 2025, may have more surprises than initially thought. New modeling suggests the asteroid formed around 150 million years ago when a larger parent asteroid broke apart, resulting in significant changes to its orbit and spin properties.
The Lucy spacecraft will collect data on Donaldjohanson’s shape, surface geology, and cratering history, providing independent insights into its formation process. According to Simone Marchi, deputy principal investigator for Lucy, “Understanding the formation of Donaldjohanson could help explain its peculiarities.”
Scientists have also discovered that Donaldjohanson may be elongated and a slow rotator, possibly due to thermal torques that have slowed its spin over time. The asteroid is part of the Erigone collisional family, a group of asteroids created when a larger parent asteroid broke apart.
Keith Noll, Lucy project scientist at NASA’s Goddard Space Flight Center, said, “We can hardly wait for the flyby because Donaldjohanson’s characteristics appear very distinct from other asteroids. Yet, we may uncover unexpected connections.”
The upcoming encounter will provide crucial data to validate models and gain a deeper understanding of this asteroid. The Lucy mission aims to revolutionize our knowledge of the origin of humanity’s home world by visiting 11 asteroids over its 12-year mission.
Source: https://www.nasa.gov/centers-and-facilities/goddard/new-modeling-assesses-age-of-next-target-asteroid-for-nasas-lucy