Overview
- NASA’s Lucy spacecraft, which flew by (52246) Donaldjohanson on April 20, 2025, returned high-resolution images showing a tumbling, two-lobed “peanut” about half a mile across.
- Spectral data detected iron-bearing phyllosilicates, a type of clay formed by exposure to liquid water, indicating the object experienced limited aqueous alteration.
- Surface features and crater counts point to a collisional origin roughly 155 million years ago, consistent with the asteroid being reassembled from fragments of a larger carbon- and water-rich parent body.
- The April 2025 encounter served as an operational dress rehearsal that validated Lucy’s cameras, spectrometers and mission procedures ahead of its primary Trojan asteroid visits.
- Scientists say the results both link small, volatile-rich main-belt objects to meteorite families and set expectations that Lucy’s 2027 Trojan observations could refine models of early solar system formation.