The Moon: Internal Structure
- Like the Earth, the Moon has a crust, mantle, and core.
- The lunar crust is rich in minerals and has an average crustal
thickness of 60 to 70 kilometers, which is about 3 times the average crustal
thickness on Earth.
- The lunar mantle lies between the crust and the core and consists mostly of
- The core is probably composed mostly of iron and sulfur and extends from the
center of the Moon out to a radius of no more than 450 kilometers, i.e.,
the core radius is less than 25% of the Moon's radius,
which is quite small.
The Moon has cold, dry interior.
- Because the Moon is smaller than Earth, it is expected to have cooled more
rapidly, producing a cold interior.
- The absence of water may be due either to the failure of the Moon to
accumulate water when it formed or to subsequent loss of water to space.
- Below 1000 kilometers depth, there is possibly
indication of the presence of a small amount of molten rock.
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