Iron 'snow' may explain Mercury's magnetic field
New Scientist: Flakes of iron snow could be falling inside the planet Mercury, according to a new experiment. This hot metal snowfall might help generate Mercury's puzzling magnetic field.
Researchers in the US have attempted to recreate the likely conditions within Mercury's liquid outer core, which is thought to be a mixture of iron and sulphur.
They used an arrangement of magnesium-oxide blocks, called a multi-anvil cell, to squeeze their iron and sulphur mixture to immense pressures, at temperatures above 2000 °Celsius. Iron crystals formed in the mixture.
"We saw iron crystals gathered at the bottom of the sample, while the liquid phase stayed on top," says team member Jie Li of the University of Illinois in Urbana-Champaign. Mercury's iron snow should form simple cubic crystals, rather than the intricate hexagonal patterns of water-ice snowflakes on Earth.
Related article Non-ideal liquidus curve in the Fe-S system and Mercury's snowing core, Geo. Rev. Lett 35, L077201
Researchers in the US have attempted to recreate the likely conditions within Mercury's liquid outer core, which is thought to be a mixture of iron and sulphur.
They used an arrangement of magnesium-oxide blocks, called a multi-anvil cell, to squeeze their iron and sulphur mixture to immense pressures, at temperatures above 2000 °Celsius. Iron crystals formed in the mixture.
"We saw iron crystals gathered at the bottom of the sample, while the liquid phase stayed on top," says team member Jie Li of the University of Illinois in Urbana-Champaign. Mercury's iron snow should form simple cubic crystals, rather than the intricate hexagonal patterns of water-ice snowflakes on Earth.
Related article Non-ideal liquidus curve in the Fe-S system and Mercury's snowing core, Geo. Rev. Lett 35, L077201
