[Rockhounds] Why does Earth have magnetic poles?

[Kreigh Tomaszewski]

Earth is unique in the *solar system*
<https://www.livescience.com/tag/solar-system> for a number of reasons:
It's the only planet with a breathable oxygen atmosphere, it's covered in
liquid water and it's the only celestial body (that we know of) to harbor
life. An often-overlooked characteristic that makes our planet special,
however, is that it's the only rocky body in the inner solar system
<https://www.livescience.com/tag/solar-system> with strong magnetic poles
 — your compass would be useless on Mars.

But where do these poles come from, and what do they do? To answer these
questions, let's start with a journey to the center of our planet.

Earth's core is separated into two layers: the solid inner core and the
molten metal outer core. Both layers are made of a cocktail of magnetic
iron and nickel, with a few dashes of lighter elements, such as oxygen,
silicon and sulfur.

The inner core is extremely dense and hot, like a giant incandescent
marble. But the outer core is fluid, and it swirls around this solid mass
with its own convective current. It's this constant convection that
generates Earth's magnetic field
<https://www.livescience.com/tag/earths-magnetic-field>, *John Tarduno*
<https://www.sas.rochester.edu/ees/people/faculty/tarduno_john/index.html>,
a geophysicist at the University of Rochester in New York, told Live
Science.

As heat from the inner core continuously radiates into the outer core, it
meets material cooled by plate tectonic activity. This cycle drives
convection, giving rise to the so-called geodynamo that produces the
magnetic field.

https://www.livescience.com/planet-earth/why-does-earth-have-magnetic-poles