The Earth's magnetic field is an important part of shielding us from cosmic radiation. Scientists recently found that the moon might be playing a major role in maintaining Earth's magnetic field.
The classical model of the formation of Earth's magnetic field has raised some major questions. For the geodynamo, which is the rapid motion of huge quantities of liquid iron alloy in the Earth's outer core, to actually work in the model, the Earth would have had to be completely molten about four billion years ago.
So what's wrong with this scenario? Its core would have had to cool from around 6,800 degrees Celsius at that time to about 3,800 degrees today. Unfortunately, geological evidence doesn't support this kind of cooling.
With that said, there could be another source of energy. The Earth's mantle deforms slightly due to tidal effects caused by the moon. In this case, the researchers found that this effect could continuously stimulate the motion of the liquid iron alloy in the outer core, and actually help generate Earth's magnetic field.
In fact, our planet receives about 3,700 billion watts of power through the transfer of the gravitational and rotational energy of the Earth-Moon-Sun system. This is thought to be available to bring about motion to the outer core. In fact, it's this energy that might generate the planet's magnetic field; together with the moon, this might resolve a major issue with the classical theory.
So what does it show? It reveals that the effect of gravitational forces on a planet's magnetic field can have a major impact. Not only that, but research has shown that the gravitational forces from two of Jupiter's moons, Io and Europa, can affect the magnetic field of the planet.
The findings reveal how the core of our planet experiences heating and how the moon's gravitational pull could have more of an effect than first thought. This could be extremely important when considering other planets and also when calculating our own Earth's magnetic field and the forces that cause it to respond the way it does.
The findings are published in the March 2016 journal Earth and Planetary Science Letters.
