Assertion: terrestrial planet's core | /r/HasProperty | a crystalline structure
Facets:
value: as for the iron meteorites
type: OTHER
Source sentences:
text: The nature of those materials has been a matter of controversy for the best part of a century and even now there is considerable uncertainty about some of the details, but we are virtually certain that the central (inner) core is a crystalline structure consisting of pure or nearly pure nickel-iron, similar to the iron meteorites which fall on the Earth from outer space.
text: And the easiest (and based on laboratory experiments and theoretical calculations, the best) way to explain this is if the inner core is a crystalline structure consisting of nearly pure nickel-iron, as for the iron meteorites, while the outer core is a mixture of similar materials with additional materials that depress the melting temperature in the same way that salt depresses the melting temperature of ice (pure ice melting at 32 Fahrenheit, and very salty ice melting at 0 Fahrenheit, so that at intermediate temperatures pure ice can exist as a solid floating in a salty mixture of water and other materials, as in polar seas).