The Magnetic Earth!

Here you will earn about Earth's magnetic field, and how it shields us from solar storms!!

If you have any questions about Earth's magnetism, visit Ask the Space Scientist!

Magnetism: Have you ever played with a magnet? Surrounding every magnet is an invisible area that scientists call a 'field'. The Earth is also a giant magnet. You can use it to find your direction by using a compass. When a solar storm reaches Earth, it makes Earth's magnetic field shake and become very disturbed. Scientists have studied Earth's magnetic field for hundreds of years. They keep track of its different parts by naming them. Look at the figure below to see what the different parts of this field in space are called.

  Watch a Magnetosphere Movie

  Look at an Enlarged Picture

  Look at another Picture 1

  Look at another Picture 2

The Magnetosphere: Earth's invisible magnetic field is shaped like a comet. It has a long tail that stretches millions of miles behind Earth in the opposite direction from the Sun. The stormy clouds and winds from the Sun pull at this tail and make it flap and shake. Like pulling taffy, pieces of this magnetic tail break off and flow out into distant parts of the solar system. The rest of the magnetic tail snaps back towards Earth. Gases that are trapped in this invisible, magnetic 'taffy' flow towards Earth too where they can cause other phenomena to happen.

 Watch a Magnetotail Movie

 Look at an Enlarged Picture

  Look at another Picture 1

Ring Current: Some of the trapped particles will take a detour and join other invisible gases that flow around Earth. One of these collections of gas is called the Ring Current. It's a gigantic river of electrified particles. Like a current of electricity flowing in a wire, it also creates its own magnetism. A battle between the Ring Current magnetism and Earth's magnetism causes many changes to take place. Because everything in space is connected, changes in one place, cause changes to take place in another place.

 Watch a Ring Current Movie

 IMAGE satellite Picture 1

Van Allen Belts Earth is surrounded by clouds of invisible particles, which some artist probably has colored purple and blue. Textbooks will then tell you that these are called the van Allen Radiation Belts. The 'Belts' are an example of particles that are trapped in Earth's magnetic field much like fireflies trapped in a bottle. Although artists like to draw them as though they look like dense clouds of gas, they are so dilute that astronauts don't even see them, or feel them, when they are outside in their spacesuits. They are so dilute, in fact, that scientists didn't know they existed until they could put sensitive instruments inside satellites and study these clouds directly. This was one of the very first experiments conducted at the dawn of the Space Age in the late 1950's. Back then, scientists such as Prof. James van Allen at Iowa State University were very interested in particles called cosmic rays, which other physicists had detected from the ground as far back as the 1930's. Where do the particles in the belts come from? Scientists are still not sure!

 Watch a Ring Current Movie

 Look at an Enlarged Picture

 Look at Drawing 1

 Look at Drawing 2

Shaped like two nested donuts, the outer belts contain fast-moving electrons. The Inner belt contains slower-moving protons.

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