Want to stay on top of all the space news? Follow @universetoday
on Twitter If you could take the entire planet, sort it out into
its various elements into piles, you’d have the following: 32%
iron, 30% oxygen, 15% silicon, 14% magnesium, 3% sulfur, 2%
nickel, and then much smaller piles of calcium, aluminum, and
other trace elements. Obviously, we don’t breath an iron
atmosphere or swim in oceans of silicon. The elements of Earth
are layered in the planet. We live on the outermost layer of
Earth, called the crust. This varies in depth between 5 and 75
km. It’s mostly made of silicates, with a tremendous amount of
oxygen mixed in. In fact, 47% of the Earth’s crust is oxygen.
The thickest parts of the crust are under the continents, and
the thinnest parts are underneath the oceans. Beneath this crust
is the mantle, which goes down to a depth of 2890 km. It’s the
largest layer on Earth, and mostly consists of silicate rocks
rich in iron and magnesium. Volcanoes are places where this
mantle wells up through the