China's Shenzhou-23 crew members aboard the country's space station give a "Tiangong Class" space lecture for students in Hong Kong and Macao special administrative regions (SAR) on Wednesday.

The three astronauts – Zhu Yangzhu, Zhang Zhiyuan and Li Jiaying (or Lai Ka-ying in Cantonese) – served as space teachers. More than 200 primary and secondary school students from Hong Kong and Macao attended the class from the Tsuen Wan Public Ho Chuen Yiu Memorial College in Hong Kong, the alma mater of Li, Hong Kong’s first payload specialist, while many more students across the two regions watched the livestream.

During the lecture, the astronauts demonstrated a series of experiments highlighting the unique environment of space, including the fixed-axis property of a gyroscope in microgravity, the station’s three-module layout and the space kitchen, as well as baking a cake, exercising on a space treadmill, and wringing water from a wet towel.

They also demonstrated a flying Bauhinia flower, introduced the space vegetable garden and conducted a "water-ball ping-pong" experiment. The astronauts also introduced space station facilities involving Hong Kong researchers, including the "Tianyun" camera.

The event featured scientific explanations, demonstrations conducted aboard the space station and questions from students, followed by a live dialogue between the astronauts and students in Hong Kong and Macao.

The lecture was jointly hosted by the governments of Hong Kong and Macao SARs and the China Manned Space Agency. Hong Kong Chief Executive John Lee and other government officials from both regions also attended.

During the dialogue, students asked the astronauts about space food, how they prepare for intensive training, the use of AI aboard the space station, silkworm breeding and biological experiments in space, preparations for extravehicular activities, and how to make choices in life.