裡面也有生命體存在，只不過按照地球現有的條件，是沒法在裡面生存的，加強跟地心文明的交流，應該在南極的軟質層有進入地心文明的通道，月球內部也是中空的，可以作為實驗基地沒必要從地球上搬過去，有很多東西可以在月球上開發的，高文明必有高素質，諸位仍需努力

the sun is a planet, because planets can give away light and heat, but the stars can not give away light and heat.

The sun is a planet,the main body of the solar system, occupies 99.86% of the total solar system. In addition, it is also the brightest star, it illuminates the darkness of the earth, brings light, all things grow by the sun!

It was so huge that is takes 1.3 million earths to fill its stomach, which is 109 times the diameter of the earth, mass is about 330000 times that of the earth.

Although it"s name is called a planet, it is not have eternal life. It will grow old and die. In about 5 billion years, the sun"s energy is almost exhausted, it will Become a red giant star. the outer layer of the sun will flee or be peeled off, leaving only the hot core, incarnating as a white dwarf star. and it will gradually to dark and colden,is become a black dwarf star.

in addition, although the sun is a star, it moves very fast on the celestial sphere. It can circle around in a year. It was recognized as a planet in the 18th century.