A visitor takes photos at a planetarium in Lhasa, southwest China's Tibet Autonomous Region, Dec. 14, 2019. An planetarium opened its door to the public for trial operation in Lhasa on Saturday. (Photos: Xinhua)

A visitor takes photos at a planetarium in Lhasa, southwest China's Tibet Autonomous Region, Dec. 14, 2019. An planetarium opened its door to the public for trial operation in Lhasa on Saturday.

Books are seen at a store in a planetarium in Lhasa, southwest China's Tibet Autonomous Region, Dec. 14, 2019. An planetarium opened its door to the public for trial operation in Lhasa on Saturday.

Visitors are seen at a planetarium in Lhasa, southwest China's Tibet Autonomous Region, Dec. 14, 2019. An planetarium opened its door to the public for trial operation in Lhasa on Saturday.

Elementary school students visit a planetarium in Lhasa, southwest China's Tibet Autonomous Region, Dec. 14, 2019. An planetarium opened its door to the public for trial operation in Lhasa on Saturday.

Visitors are seen at a planetarium in Lhasa, southwest China's Tibet Autonomous Region, Dec. 14, 2019. An planetarium opened its door to the public for trial operation in Lhasa on Saturday.

Visitors watch a movie at a dome theatre in a planetarium in Lhasa, southwest China's Tibet Autonomous Region, Dec. 14, 2019. An planetarium opened its door to the public for trial operation in Lhasa on Saturday.

Photo taken on Dec. 14, 2019 shows the exterior view of a planetarium in Lhasa, southwest China's Tibet Autonomous Region. An planetarium opened its door to the public for trial operation in Lhasa on Saturday.

Visitors are seen at a planetarium in Lhasa, southwest China's Tibet Autonomous Region, Dec. 14, 2019. An planetarium opened its door to the public for trial operation in Lhasa on Saturday.

Visitors view a meteorite at a planetarium in Lhasa, southwest China's Tibet Autonomous Region, Dec. 14, 2019. An planetarium opened its door to the public for trial operation in Lhasa on Saturday.