The chapter studies ancient Chinese astronomy, which focused on computing and predicting the movements of the heavens (天 tian), the sun, moon, stars, and asterisms, which was the duty of the rulers, in order that the people be well-regulated. Heavenly bodies were allocated to terrestrial zones, especially 28 constellations roughly along the equator or the ecliptic, the seven stars of the Big Dipper (regarded as the carriage of heaven), and the five planets. Unusual celestial phenomena were recorded, such as solar eclipses, comets, and meteorites. The 盖天 gai tian theory (celestial dome theory), the 浑天 hun tian Theory (celestial sphere theory) and the 宣夜 xuan ye theory (infinite empty space theory) were the three primary theories of the structure of the heaven and the earth, in the Han dynasty (202 bce—220 ce). The earliest extant Chinese star catalogue of the whole sky was composed in the 1st century bce, and the definitive constellation system of 283 constellations, 1464 or 1465 stars was composed in the 3rd century ce.