NASA's Lucy Mission to the Trojan Asteroids

The Lucy mission, which is part of NASA's Discovery Program, is the first reconnaissance of the Jupiter Trojans, objects that hold vital clues to deciphering the history of the Solar System. Due to an unusual and fortuitous orbital configuration, Lucy will perform a comprehensive investigation that visits seven of these primitive bodies, covering both the $\mathbf{L}_{4}$ and $\mathbf{L}_{5}$ swarms and all the known taxonomic types. In particular, Lucy will perform flybys of 3548 Eurybates and its satellite Queta ( $\mathbf{L}_{4}$ , C-type), 15094 Polymele ( $\mathbf{L}_{4}$ , P-type), 11351 Leucus ( $\mathbf{L}_{4}$ , D-type), 21900 Orus ( $\mathbf{L}_{4}$ , D-type), and the 617 Patroclus-Menoetius binary ( $\mathbf{L}_{5}$ , P-types). Eurybates and the binary are of particular interest. Eurybates is the largest member of the only major disruptive collisional family in the Trojan swarms. The Patroclus-Menoetius binary, which consists of two roughly equal mass objects in a circular mutual orbit, is likely a leftover from the first generation of planetesimals in the Solar System.