New idea tackles Earth core puzzle

Scientists have proposed a radical new model for the make-up of the Earth's core.

The study may explain a longstanding puzzle about the most inaccessible part of our planet.
It suggests that differences between the east and west hemispheres of the core are explained by the way iron atoms pack together.
Details appear in the journal Scientific Reports.
Lying more than 5,000km beneath our feet, at the centre of the Earth, the core is beyond the reach of direct investigation. Broadly speaking, it consists of a solid sphere of metal sitting within a liquid outer core.
The inner core started to solidify more than a billion years ago. It has a radius of about 1,220km, but is growing by about 0.5mm each year.
But the stuff that the core is made from remains a longstanding unresolved problem.
Clues come from the speeds that seismic waves generated by earthquakes pass through the core.

http://www.bbc.co.uk/news/science-environment-23180271