Opportunities for a Dinkinesh-Sized Trojan Flyby in the L5 Cloud

Spacecraft flybys offer unparalleled opportunities to investigate small Solar System bodies. These encounters enable disk-resolved imaging and spectroscopy, revealing surface composition, morphology, collisional history, and the potential presence of satellites, capabilities that far exceed what is achievable from Earth. Despite their scientific utility, such encounters remain rare due to the high costs and operational complexity of spacecraft missions. Within this context, NASA’s Lucy mission stands out, having completed two flybys of Main Belt Asteroids and targeting five flybys within the Jupiter Trojan clouds. Lucy’s recent encounter with (152830) Dinkinesh, a ~700-meter MBA, yielded striking and unexpected returns, including the discovery of a contact binary satellite, highlighting the unique scientific value of sub-kilometer targets. Notably, only one of the five Jupiter Trojan flybys target the L₅ cloud, raising the question of whether it is possible to identify an additional Dinkinesh-sized L₅ Jupiter Trojan flyby target for Lucy. In this talk, we present estimates of the number of sub-kilometer L₅ Trojans accessible to Lucy under two operational scenarios:  before and after the Patroclus-Menoetius flyby. We describe an improved model of the L₅ cloud’s spatial distribution and outline the observational constrains (sky area, search window, and survey duration) required to enable a targeted search. Finally, we discuss the scientific impact of such a flyby, particularly in the context of the L₄/L₅ population asymmetry.