The deepest hole humans have ever dug reaches 12 kilometers below the ground of Russia’s Kola Peninsula. Although we now have a spacecraft on its way to Pluto—about six billion kilometers away from the sun—we still cannot send a probe into the deep earth. For practical purposes, then, the center of the planet, which lies 6,380 kilometers below us, is farther away than the edge of our solar system. In fact, Pluto was discovered in 1930, and the existence of the earth’s inner core was not established—using seismological data—until six years later.

Still, earth scientists have gained a surprising amount of insight about our planet. We know it is roughly structured like an onion, with the core, mantle and crust forming concentric layers. The mantle constitutes about 85 percent of the earth’s volume, and its slow stirring drives the geologic cataclysms of the crust. This middle domain is mainly a mix of silicon, iron, oxygen, magnesium—each of which appears in roughly the same concentrations throughout the mantle—plus smaller amounts of other elements. But depending on the depth, these elements combine into different types of minerals. Thus, the mantle is itself divided into concentric layers, with different minerals predominating at different depths.

4 Comments

1. 1. tharriss 11:03 AM 6/3/10

   Nice Albert... I'm sure everyone understood that on the first read! :-)

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2. 2. vadxor in reply to Albert Meinstein 06:31 AM 6/4/10

   translation, please! or code listing, or manual?!
   evtly medical release papers.
   

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3. 3. debu 11:57 PM 6/7/10

   The center of earth is getting focussed gravitoethertons which create a very high temperature for hot molten iron core and the magnetism of gravitoethertons and flow of electrons due to dynamism . Read my ether=gravity=dark energy theory of gravitoethertons. Links available in --durgadas datta facebook--

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4. 4. YahyaA 03:00 AM 6/10/10

   It's a pity if Kei Hirose's line of work hasn't yet taken him to Antarctica. But surely exploring the liquid iron outer core in a diamond anvil is every bit as unforeseen as exploring the deep sea in a submersible? And under much greater pressure, too!
   
   Here's to adventurous scientists, and to many more wonderful discoveries. Even if no other is as earth-shattering as postperovskite, we'll have plenty to celebrate him for!
   
   BTW, "postperovskite" is too derivative a name for a substance of such fundamental importance to earth science. Why not call it "hiroseite"?
   

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