Active Asteroid, Quasi-Hilda, and Jupiter Family Comet Discovery with Citizen Science

Comets and asteroids, historically considered two separate populations, have become increasingly indistinguishable. One population that blurs the comet-asteroid boundary is the active asteroids, asteroids with features most often associated with comets, such as tails or comae. These objects provide insight into astrophysical processes (e.g., dynamical evolution), and help us map the past and present-day solar system volatile distribution. Asteroid activity is elusive, with only about 50 active asteroids identified among the 1.1 million known asteroids. An even smaller subset (roughly 20 objects) are the main-belt comets, asteroids experiencing sublimation-driven activity while orbiting within the main asteroid belt. To help find more active asteroids, thereby enabling the comprehensive study of these bodies as a population, we have embarked on a campaign to find more of these objects with the help of the public. We have created a Citizen Science project, Active Asteroids (http://activeasteroids.net), where we show volunteers images of known minor planets that we have produced from publicly available Dark Energy Camera data and ask them if they see activity or not. Launched on the Zooniverse online Citizen Science platform in August 2021, our NASA Partner program has received help from over 8,000 participants to carry out over 6 million classifications. Here we present the Active Asteroids program along with new results, including new active asteroids, quasi-Hilda objects, and Jupiter Family Comets, as well as updated statistics about these populations, such as their occurrence rates. This material is based upon work supported by the NSF Graduate Research Fellowship Program under grant No. 2018258765 and grant No. 2020303693. C.O.C., H.H.H., and C.A.T. acknowledge support from NASA grant 80NSSC19K0869. W.J.O. and C.A.T. acknowledge support from NASA grant 80NSSC21K0114. W.A.B. was supported in part by NSF award 1950901. This work is funded in part through the LSST Interdisciplinary Network for Collaboration for Computing (LINCC) Frameworks. LINCC Frameworks is supported by Schmidt Futures, a philanthropic initiative founded by Eric and Wendy Schmidt, as part of the Virtual Institute of Astrophysics (VIA).