Lucy mission
Lucy is a NASA mission launched in 2021 to fly past several Trojan asteroids that share Jupiter's orbit.
Lucy is a NASA spacecraft launched in October 2021. It is named after the famous fossil human ancestor nicknamed Lucy, because the Trojan asteroids it will visit are thought of as fossils of planet formation. Its huge solar arrays let it operate far from the Sun.
The Trojans are two swarms of asteroids that share Jupiter's orbit, one leading the planet and one trailing it. Lucy will make a series of flybys, using Earth gravity assists along the way. In November 2023 it flew past the small main-belt asteroid Dinkinesh and discovered it has a moon made of two touching lobes. It flew past asteroid Donaldjohanson in April 2025, and its Trojan encounters are planned from 2027 onwards.
Trojans may preserve material from the outer Solar System that was captured during a period when the giant planets moved. Understanding them helps link the dark, primitive meteorites to their possible sources.
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