ASTR 20 Lecture Notes - Lecture 12: Solar Luminosity, Cambrian, Photosynthesis
Document Summary
The moon did not co-form with the earth. The earth has a bulk density of 5. 5 grams per cubic centimeters. The moon has a density of 3. 3 grams per cubic centimeters. The moon formed by accretion somewhere else in the solar system where the material would form an object with a density of ~3. 5 g/cc. Since the mantle of the earth has a density of 3. 5 g/cc then the overall composition of the moon must be like that of the earth"s mantle. This was a mysterious problem for about 30 years until finally, computer simulations improved to the point that offered a plausible explanation. Step 1: a tidal force is exerted on the molten earth which causes an obvious. Step 2: the deformation actually separates from the earth initially as a whole molten blob whose composition again reflects the middle layers of the earth.
