Iron Snow

The universe is just chock full of wonders. Remember silicon clouds?

This model would take place hundreds of miles in Mercury’s interior, but it’s a fascinating process that might explain Mercury’s magnetosphere. Nancy Atkinson has the details at Universe Today. Why would Mercury have one and Venus and Mars, both larger planets lack one? It might have to do with the mix of sulfur and iron thought to make up Mercury’s core. (Earth’s iron is mixed with nickel, by comparison.)

Scientist Bin Chen and his team melted a mixture of iron and sulfur under the intense pressures existing in the core of a planet. Here’s what they found:

In each experiment, an iron-sulfur sample was compressed to a specific pressure and heated to a specific temperature. The sample was then quenched, cut in two, and analyzed with a scanning electron microscope and an electron probe microanalyzer.

As the molten, iron-sulfur mixture in the outer core slowly cools, iron atoms condense into cubic “flakes” that fall toward the planet’s center. As the iron snow sinks and the lighter, sulfur-rich liquid rises, convection currents are created that power the dynamo and produce the planet’s weak magnetic field.

The Messenger space probe can test some of this as it passes Mercury this October and studies that weak global magnetic field.

More Mercury news this week:

Universe Today’s Nancy Atkinson also tells you what to expect should your spacesuit fail while you were exploring Mercury.

The International Astronomical Union (IAU) has approved names for Mercurian features first imaged by Messenger on its January flyby earlier this year.

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About catholicsensibility

Todd and his family live in Ames, Iowa. He serves a Catholic parish of both Iowa State students and town residents.
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