The Earth’s Magnetic Field Is Essential For Our Survival, But What Exactly Is It?
The Earth has a huge shield around it that protects it (and us) from things like solar wind and other ‘space weather’ that could reak havoc on the planet, our electronics, and much more.
This shield is known as the magnetosphere and while we can’t see it with our eyes, humans have known about it since it was located by the British Royal Navy officer Sir James Clark Ross in 1831.
Our magnetosphere is quite strong when compared to other rocky planets. Mars once had a magnetic field for protection, but it no longer exists. Scientists continue to study the planet to try to figure out exactly when it dissipated, and more importantly, why.
Mercury does have a magnetosphere, but it is only about 1% as strong as ours according to NASA. That is not nearly enough to protect it from the solar winds and other threats from space that would be required to house life similar to Earth. Especially since it is so much closer to the Sun than Earth is.
Our magnetic field is generated by a layer of hot liquid that is made up mostly of nickel and iron. This ‘lake’ of liquid metal is deep below the surface of the planet in what is considered the outer core.
As that metal moves around, it generates massive amounts of fast-moving electricity, which produces the magnetic field around our planet.
Interestingly, the magnetic poles that are created are not in the same place as the geographic poles, and they are not stable. NOAA reports that the magnetic pole is moving north-northwest at a rate of about 55 kilometers (34 miles) per year. It is currently near Siberia.
Not only does the pole move over time, but there is evidence that the polarity actually flips approximately every 300,000 years according to NASA. The last time it flipped was about 780,000 years ago, which means we are way past due. Some people believe that the movement of the poles is the beginning of this process, but that is not known.
Experts also don’t know exactly how a flip of the poles would impact our magnetosphere or our electronics and other systems. Fortunately, a flip in this way would take hundreds, or even thousands, of years to fully complete so there would be time to adjust as needed.
To see these magnetic fields and learn more about them, consider watching this video from NASA:
It is crazy to think that we have a magnetic shield around the planet.
If you thought that was interesting, you might like to read about 50 amazing finds on Google Earth.

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