关于天文学的英语演讲短文

Answer 1

Also known as the Moon Taiyin, commonly known as the moon [1]. The Earth are the only natural satellite. Moon is the most obvious examples of natural satellites. In the solar system, with the exception of Mercury and Venus, the other planets have natural satellites. There is around the age of the moon 4.6 billion years. Has the moon shell, mantle, core, such as Hierarchy. On the outermost shell of average thickness of about 60-65 km. Shell month following the month are 1000 kilometers deep mantle, it accounts for most of the size of the moon. Mantle on the following month are nuclear, nuclear month temperature of about 1000 degrees, melting is likely to be the status. The Moon about 3476 kilometers in diameter, are of the Earth 3 / 11, Sun 1 / 400. The size of the moon the Earth is only 1 / 49, the quality of about 7350 quadrillion tons, equivalent to the quality of the Earth 1 / 81, the lunar surface gravity of the Earth gravity is almost 1 / 6.