帮我看看、检查检查些列句子有没有语法错误（英语）
The moon is the most thoroughly studied celestial.The moon's age is about 4600000000 years.The moon and the earth as a shell,mantle,core layer structure.The outer shell of the month average thickness of about 60-65 km.Lunar crust below to 1000 km depth is the lunar mantle,it accounts for most of the volume of the moon.