Lucy is the first space mission to explore a diverse population of small bodies known as the Jupiter Trojan
asteroids. These remnants of our early solar system are trapped on stable orbits associated with – but not close to – the giant planet Jupiter. Trojan asteroids orbit in two “swarms” that lead and follow Jupiter in its orbit around the Sun and are thought to be comparable in number to the objects in the main asteroid belt between the orbits of Mars and Jupiter.
Over its 12-year mission, Lucy will explore a record-breaking number of asteroids: it will by two (plus a newly discovered satellite) in the belt of asteroids that circle the Sun between the orbits of Mars and Jupiter, and then eight Trojans, which includes five asteroid targets and the satellites of three of those. Lucy also will fly by Earth three times to get a push from its gravity, making it the first spacecraft to return to the vicinity of Earth from the outer solar system.
Lucy is named for a fossilized skeleton of a human ancestor, which was named for the Beatles song "Lucy in the Sky with Diamonds."
The Lucy mission is named after the fossilized skeleton of an early hominin (pre-human ancestor) that was found in Ethiopia in 1974 and named “Lucy” by the team of paleoanthropologists who discovered it. And just as the Lucy fossil provided unique insights into human evolution, the Lucy mission promises to expand our knowledge of planetary origins.