Observations and Speculations about the Earth's Core

Research at Stamford University on molten iron and the Earth's core led to some interesting results. However, there are still some unanswered questions, such as the slow rate of travel of seismic waves.

NASA/Dixon Rohr
Indirect methods of assessment give some results, but extrapolating these into explanations of the formation of the Earth (such as accretion, or the nebular hypotheses) do not work. In addition, discarded "percolation" theories are being resuscitated, since evolutionary conjectures do not supply the answers.
Journey to the center of the earth said to show how our core came to be.
Without our magnetic field, earth would be a very different place. Earth’s magnetic field protects us from cosmic radiation. The magnetic field is a shield, deflecting harmful charged particles and thereby guarding our upper atmosphere, including the ozone layer, from the solar radiation that would destroy it and, with it, the conditions that support life. Our magnetic field is generated by the motion of liquid iron alloy in earth’s outer core, driven by the intense heat of the iron alloy in the solid inner core. But how did earth’s metallic iron core ever become separate from the overlying mantle?
You can read the rest of this hot topic, "Does the Secret of the Earth’s Origin Abide in the Planet’s Core?"