It's a common refrain that the ocean depths are the last great frontier of the Earth. Yet there's a place that's even more inhospitable to humans than the crushing depths of the sea: our planet's interior. read more
The molten iron outer core lies about 3000 kilometers below our feet, while the solid iron inner core is another 2000 kilometers further down. A few other elements, including oxygen and silicon, are thrown in for good measure. But for the most part, iron rules the Earth's underbelly. To learn more about Earth's innards, scientists have looked outward. read more
“We believe that silicon is a major element – about 5% [of the Earth's inner core] by weight could be silicon dissolved into the iron-nickel alloys,” lead researcher Eiji Ohtani, a professor of petrology and geophysics at Tohoku University, told BBC News. read more