Introduction to the Astronomical Hall: The sky of the Astronomical Hall is 23 meters in diameter and has 315 seats. It is one of the largest astronomical halls in the world. The hall is also equipped with a very innovative full-sky projector, the first to be used in Asia. The six-channel sound system in the hall has dozens of speakers and the effect is excellent. It is the first all-sky movie projection equipment in the Eastern Hemisphere and the first astronomy museum in the world with a fully automatic astronomical program control system. Most of the programs are narrated in Cantonese, and some programs are narrated in English. Audiences can use headphones in the Astronomical Hall to choose narration in Cantonese, English, Mandarin or Japanese.