Earth’s Magnetic field tagged posts

The bottom-most layer of the moon’s mantle melts to form a metal-rich “basal magma ocean” that sits on top of the moon’s metal core. Convection in this layer may have driven a dynamo, creating a magnetic field which would have been recorded at the surface by the cooling lunar crust, including the samples brought back by Apollo astronauts. Credit: Aaron Scheinberg

Around 4 billion years ago, the Moon had a magnetic field that was about as strong as Earth’s magnetic field is today. How the Moon, with a much smaller core than Earth’s, could have had such a strong magnetic field has been an unsolved problem in the history of the Moon’s evolution...

The geomagnetic field is critical to life on Earth. Without it, charged particles from the sun (the “solar wind”) would blow away the atmosphere, scientists say. Credit: © SkyLine / Fotolia

Scientists have identified patterns in Earth’s magnetic field that evolve on the order of 1,000 years, providing new insight into how the field works and adding a measure of predictability to changes in the field not previously known. The discovery also will allow researchers to study the planet’s past with finer resolution by using this geomagnetic “fingerprint” to compare sediment cores taken from the Atlantic and Pacific oceans.

The geomagnetic field is critical to life on Earth. Without it, charged particles from the sun (the “solar wind”) would blow away the atmosphere, scientists say...

This is an illustration of how the diamond anvil cell is used to mimic and study planetary core conditions. Credit: Stewart McWilliams

Earth’s magnetic field shields us from deadly cosmic radiation, and without it, life as we know it could not exist here. The motion of liquid iron in the planet’s outer core, a”geodynamo,” generates the field. But how it was first created and then sustained throughout Earth’s history has remained a mystery to scientists. New work sheds light on the history of this incredibly important geologic occurrence.

Earth accreted from rocky material that surrounded our Sun in its youth, and over time the most-dense stuff, iron, sank inward, creating the layers that we know exist today–core, mantle, and crust...