2009 作文小组 招新 8.26第9次作业

lsr91UID: 2540702

8.26
高分120 practice 3&

My answer:
In the lecture, the professor made several points about how did the moon formed. The professor argues that there is no trace can provide the moon is a part of the Earth. However, the reading contends that a piece of space debris the size of Mars struck the Earth just after the formation of the solar system. And this matter eventually coalesced to from the moon.

The first point that the professor uses to cast doubt on the reading is that there are some traces has been found on the surface of moon to prove the giant-impact theory. According to the professor, there is no trace of collision and all rocks made by force of nature, all of them are earth and space's work. What lecture says differs from the reading in that the reading states yet so far, no trace of a giant impact has been found on the surface of the Earth.

Another point that the professor uses to casts doubt on the reading is rocks on the moon, they don't contain any water. The professor claims that the temperature on the moon is too high that water is evaporated and cannot stay in liquid on the moon. However, the reading states that the rocks on the Earth and the moon are quite different from that on the earth. So the rocks on the moon contain few volatile substances such as water.

Finally, the professor stated that, on the contrary of the reading, the density of the moon is same as the surface of the earth. Maybe it is more alike the core of the earth. In other words, the moon is not made by the giant-impact. This directly contradicts what the reading passage indicates, because it states that the differences between the moon and the earth greatly weaken the giant-impact theory.