Astro (Korean: 아스트로; stylized in all caps) is a South Korean boy band formed by Fantagio. The group is composed of four members: MJ, Jinjin, Cha Eun-woo, and Yoon San-ha. Originally a six-piece group, Rocky departed from the group on February 28, 2023,[3] and Moonbin died on April 19, 2023.[4] They debuted on February 23, 2016, with the extended play Spring Up and were subsequently named as one of the best new K-pop acts of 2016 by Billboard.Astro was formed through the rookie talent development program "iTeen Boys", which was created by their agency Fantagio.[6] In August 2015, the final member line-up and group name were announced.[7] The same month, the group starred in a web drama titled To Be Continued, which aimed to introduce them to the public. The drama featured the members as themselves, as well as Kim Sae-ron, Seo Kang-joon, and the girl group Hello Venus