NASA’s Lucy spacecraft has successfully completed its second asteroid flyby, capturing stunning close-up images of the peanut-shaped asteroid Donaldjohanson. This remarkable encounter occurred on April 20, 2025, with Lucy approaching within 600 miles (960 kilometers) of the asteroid. The images reveal new details about this intriguing celestial body, a fragment of a much larger space rock that shattered approximately 150 million years ago.
NASA’s Lucy spacecraft’s first views of the asteroid Donaldjohanson. The asteroid is outlined with a square in the right image to guide the eye.
Lucy’s Second Asteroid Encounter: A Glimpse into the Solar System’s Past
The Lucy mission, named after the famous hominid fossil discovery, is providing invaluable insights into the early solar system. Donaldjohanson, named for the anthropologist who discovered the fossil, is a relatively small asteroid, measuring roughly 5 miles (8 kilometers) across. This updated size estimate is larger than previous calculations of 3 miles (4 kilometers) made when Lucy was farther away. The flyby allowed NASA scientists to test Lucy’s onboard instruments, including the color imager, infrared spectrometer, thermal infrared spectrometer, and the L’LORRI high-resolution imager responsible for the close-up images. This successful test is crucial for the upcoming encounter with the Trojan asteroid Eurybates in August 2027.
Donaldjohanson: A Contact Binary Asteroid
Donaldjohanson is categorized as a contact binary asteroid, a type formed when two smaller asteroids collide and fuse together. This process results in the distinctive peanut-like shape observed in the Lucy images. The encounter with Donaldjohanson provided an unexpected opportunity for Lucy, as the asteroid is not a Trojan asteroid, the mission’s primary target. However, its convenient location allowed for a productive detour en route to the Trojan asteroids near Jupiter.
Djencounter Movie Release V2
From Dinkinesh to Donaldjohanson: Lucy’s Ongoing Journey
This flyby marks Lucy’s second asteroid encounter. In November 2023, Lucy flew past the tiny asteroid Dinkinesh, measuring only 0.5 miles (790 meters) across. This marked the first time a spacecraft observed a contact binary asteroid up close. The successful observations of both Dinkinesh and Donaldjohanson highlight the potential for further discoveries as Lucy continues its journey to the Trojan asteroids.
Lucy’s Future Explorations: Unraveling the Trojan Asteroids
The Trojan asteroids, located in Jupiter’s orbit, are believed to be remnants from the early solar system. By studying these ancient celestial bodies, scientists hope to gain a deeper understanding of planetary formation and the evolution of our solar system. The data collected from the Donaldjohanson flyby, including the high-resolution images and spectral data, provides valuable experience and prepares the Lucy team for the upcoming exploration of the Trojan asteroids, starting with Eurybates in 2027. With its successful flybys and advanced instrumentation, the Lucy mission promises to unlock further secrets of our solar system’s past.
