In Aristotle's (384–322 BC) description of the universe, the Moon marked the boundary between the spheres of the mutable elements (earth, water, air and fire ), ... en.wikipedia.org |
3 Nov 2008 ... The crust of the Moon is composed mostly of oxygen, silicon, magnesium, iron, calcium, and aluminum. There are also trace elements like ... www.universetoday.com |
The surface of the Moon has two hemispheres with rather asymmetric ... They are rich in refractory elements, which are elements such as calcium (Ca), ... csep10.phys.utk.edu |