P/2019 LD2 (ATLAS) is a newly discovered active centaur (Minor Planet Electronic Circular). It is on an unstable orbit, evolving towards the inner solar system and a future as a Jupiter Family Comet, in the next several decades (Kareta et al. 2020, Steckloff et al. 2020, Hsieh et al. 2021). 

P/2019 LD2 (ATLAS) presents an unparalleled opportunity to understand the transition cometary bodies experience as they evolve from the outer to inner solar system. The Centaur-Comet Gateway (Sarid et al. 2019) is a recently discovered region of small body orbital evolution where Centaurs transfer into the active comet population. P/2019 LD2 is skirting the Gateway region and may be one of the best examples of an active small body that is driven by water ice solid phase transition and sublimation flow of highly volatile species.

P/2019 LD2 presents a unique opportunity, which enables us to monitor a Centaur as its activity evolves and it transitions to an inner solar system object for what is likely the first time. It is a high priority target for characterization of composition, outgassing of volatile material and ejection of solid refractory particles.