The noun 月球 (yuèqiú) means "the Moon" and is the formal or scientific term for Earth's natural satellite. It is used in academic and news contexts, as opposed to the more colloquial 月亮. For example, 月球探索 means "lunar exploration."
科学家在月球表面发现了水的痕迹。
Kēxuéjiā zài yuèqiú biǎomiàn fāxiàn le shuǐ de hénjì.
Scientists discovered traces of water on the surface of the moon.
中国计划在未来几年实现月球载人登陆。
Zhōngguó jìhuà zài wèilái jǐ nián shíxiàn yuèqiú zàirén dēnglù.
China plans to achieve a crewed lunar landing in the coming years.
月球离地球大约三十八万公里。
Yuèqiú lí dìqiú dàyuē sānshíbā wàn gōnglǐ.
The moon is approximately 380,000 kilometers from the Earth.