Comet C/2018 Y1 (Iwamoto) is a long-period comet discovered by Japanese amateur astronomer Masayuki Iwamoto. During its 2019 apparition, the comet passed relatively close to Earth, displaying a bright green coma and a narrow ion tail. The comet moved rapidly across the sky, making it a dynamic target for astrophotographers. With an orbital period of roughly 1,371 years, the comet will not return until well into the next millennium.