Core
Several lines of evidence imply that the lunar core is small, with a radius of about 350 km or less. The size of the lunar core is only about 20% the size of the Moon, in contrast to about 50% as is the case for most other terrestrial bodies. The composition of the lunar core is not well constrained, but most believe that it is composed of metallic iron alloyed with a small amount of sulfur and nickel. Analyses of the Moon's time-variable rotation indicate that the core is at least partly molten.
In 2010 reanalysis of the old Apollo seismic data on the deep moonquakes using modern processing methods confirmed that the Moon has an iron rich core with the radius of 330 ± 20 km. The same reanalysis established that the solid inner core made of pure iron has the radius of 240 ± 10 km. The core is surrounded by the partially (10 to 30%) melted layer of the lower mantle with the radius of 480 ± 20 km (thickness ~150 km). These results imply that 40% of the core by volume has solidified. The density of the liquid outer core is about 5 g/cm3 and it can contain as much 6% sulfur by weight. The temperature in the core is probably about 1600–1700 K.
Read more about this topic: Internal Structure Of The Moon
Famous quotes containing the word core:
“It is possible to have a strong self-love without any self-satisfaction, rather with a self-discontent which is the more intense because one’s own little core of egoistic sensibility is a supreme care.”
—George Eliot [Mary Ann (or Marian)
“For books are more than books, they are the life
The very heart and core of ages past,
The reason why men lived and worked and died,
The essence and quintessence of their lives.”
—Amy Lowell (1874–1925)
“The threadbare trees, so poor and thin,
They are no wealthier than I;
But with as brave a core within
They rear their boughs to the October sky.
Poor knights they are which bravely wait
The charge of Winter’s cavalry,
Keeping a simple Roman state,
Discumbered of their Persian luxury.”
—Henry David Thoreau (1817–1862)