The Silent Sea (Korean: 고요의 바다; RR: Goyo-eui bada) is a 2021 South Korean streaming television series starring Bae Doona, Gong Yoo and Lee Joon. Director Choi Hang-yong created the series of eight episodes as an adaptation of his 2014 short film, The Sea of Tranquility, with the help of writer Park Eun-kyo. It premiered on Netflix on December 24, 2021. The title The Silent Sea comes from the Sea of Tranquility on the moon; the story follows a crewed mission to retrieve samples from a lunar research base. Mostly science fiction, it also blends genres like thriller and mystery. It received generally positive reviews from critics and audiences.