One might be able to imagine two different moons made out of the same amount of carbon, but one moon made of graphite and the other made of diamond. The two imaginary moons would have very different sizes! Then one might imagine one moon evolving into the other, and having to change sizes as it does so. This phenomena explains the evolution of the icy moons. Ice comes in nine different phases, and all of them have a different molecular construction. In it's evolution, an icy moon may change many times from one phase to another, or include many different phases in it's interior.
Two other materials, from the earth's interior, which exhibit similar phase differences are olivine and spinel.
One might be able to imagine two different moons made out of the same amount of carbon, but one moon made of graphite and the other made of diamond. The two imaginary moons would have very different sizes! Then one might imagine one moon evolving into the other, and having to change sizes as it does so. This phenomena explains the evolution of the icy moons. Ice comes in nine different phases, and all of them have a different molecular construction. In it's evolution, an icy moon may change many times from one phase to another, or include many different phases in it's interior.
Two other materials, from the earth's interior, which have similar phase differences are olivine and spinel.
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