At the center of our planet, heat and pressure are so tremendous that even the structure of iron is transformed. Now, using lasers and diamonds, researchers have reproduced those conditions in the lab. And discovered something they'd always suspected.
The researchers conducted a series of "compression experiments," and found that iron crystals change their structure under enormous heat and pressure. But how did they do it?
A team of scientists took two diamonds, which you see above, and pressed their flat tips together. Then they compressed them to "ultrahigh pressure," and heated them with lasers. Basically, that small spot between the two diamonds became so hot, and so compressed, that it was just like the Earth's core. Using x-ray diffraction measurements, the scientists were able to measure what that tiny spot was going through, and extrapolate how those conditions would affect iron crystals.
According to a release from Science:
Shigehiko Tateno and colleagues suggest that iron crystals at the center of the Earth prefer a hexagonal close-packed structure rather than one of its other cubic structures, which are known to occur at ambient conditions . . . The discovery also helps to explain some previous observations of seismic activity in the core, and it suggests that individual iron crystals in the core might orient themselves with their long, crystallographic axes parallel to Earth's rotation axis.
That's right - there are huge iron crystals aligned with the Earth's axis deep in the planet's inner core. I have to admit it sounds completely awesome, in a Balrog-is-about-to-emerge kind of way.
Read the full scientific paper via Science.