Audio Guide：

Explorations on the moon have always been a priority for space programs in many countries. In 1959, Russia launched the first space probe to have successfully flown over the Moon, Luna 1, and became the first country to develop a moon landing program. The U.S. was the first country to land humans on the moon. The renowned Apollo Program put astronauts on the moon for a total of six times and brought back over 300 kilograms of lunar soil for scientific research. Besides Russia and the U.S., other countries including Japan, Europe, China, and India have also been working on their own lunar programs. In 1990, Japan launched the Hiten, or Celestial Maiden, the third lunar satellite. The fourth lunar satellite, Smart-1, was launched by the European Space Agency and entered the lunar orbit in 2004. China’s Chang’e 1 became the fifth lunar satellite when it took off in 2007. The lunar landing mission Chang’e 4 is set to bring back lunar soil for analysis. Japan even plans to make lunar landing with robots in 2025.