Earth’s Magnetism

The power from the Earth’s magnetism starts at the core of the Earth and it flows through the Earth all the way to the magnetosphere.  The magnetosphere is like a shield that goes around the Earth so that the Earth is protected from dangerous things such as:

  • Sun
  • Radiation
  • Particles

Interesting Things About Magnetism

When something is magnetic, it is basically invisible.  There are certain things that are needed in order for something to be magnetic.  There are different objects and particles such as electrons that spin and move in all different directions and this can cause the electrons to hit into each other and to explode.  With magnets, the molecules are arranged in a way that they spin the same direction, so they are never hitting into each other.

Since the molecules never run into each other, they are constantly moving, and the force flows around and around, and it creates a magnetic field.

The reason that the North Pole and the South Poles are magnetic is because they are made up of material that is needed to make magnets such as steel and iron.

Inner and Outer Core

The inner and outer core of the Earth are made up of different types of metals such as nickel and iron and the inner core is a magnetic ball that is very large and solid.  Outside the inner core is a layer of liquid that is also metal, and it flows around the inner core, this is the outer core of the Earth.  The outer core helps to keep the inner core solid from all of the pressure that builds up from the liquid.

Both the inner and the outer core spin and when they are spinning, it causes there to be a magnetic energy.  There are two areas, the North Pole and the South Pole and these two areas have a very strong magnetic energy that pushes against each other.  Since the Earth is always rotating, these two poles are always creating energy and pushing against each other just like opposite magnets.

The Magnetosphere

The most important part of the magnetic field or the magnetosphere is that it protects the Earth from things that are dangerous such as radiation from the sun.  When the radiation comes toward the Earth, the magnetic field will bounce the radiation back into space and this helps people on Earth to be protected from so much radiation.

Without the strong magnetic field that the Earth has, the planet would not be livable.  Oceans would become dry because of the heat and the whole Earth would become too hot to live on.  One reason some of the other planets do not have oceans and lakes is because they do not have a protective magnetic field like Earth has.

The way that the magnetosphere is shaped depends on how the solar wind has moved in the atmosphere.  When solar storms happen, this can cause there to be more solar wind activity and these storms can cause a lot of damage to the Earth.  The magnetosphere helps to protect the Earth from these storms.

What Causes the Magnetic Field?

There are two things that cause there to be a magnetic field, the way that the liquid in the core moves and the electrical currents.

When the liquid in the core moves around and around, this is called convective motions.  These motions cause the liquid in the core to move in opposite directions as the Earth moves.

The second thing that is required for the magnetic field is the electrical currents.  When the movements of the liquid in the core meets with the electrical currents that are found around the Earth, this causes there to be a magnetic field.

As the Earth continues to rotate, this is what helps to keep the magnetic field from going down.

Where is the Magnetic Field the Strongest?

When the magnetic field is the strongest, it is by one of the two poles, the North or the South Pole.  The magnetic field is weaker when it is close to the equator.

Planets with a Magnetic Field

Some planets have a magnetic field and other planets don’t.  As we discussed above, the planets that do not have a magnetic field will most likely not have oceans or lakes because they get too hot and all of the water evaporates.  Here are some of the planets that have a magnetic field:

  • Jupiter
  • Uranus
  • Saturn
  • Neptune

Most of the magnetic fields on these planets are much stronger than the magnetic field of the Earth.

Other planets have no or very weak magnetic fields such as:

  • Mars
  • Venus
  • Mercury

What Can We See Because of the Magnetic Field?

When the Earth is moving and there are particles that are going towards the Earth from the sun, the Earth’s magnetic field acts like a shield.  When this happens, many of the gases still escape and go into the atmosphere of the Earth.

When this happens, we can see the Northern Lights or the Aurora Borealis or the Southern Lights or the Aurora Australis.  This causes there to be different colors of lights that make it look like a light show.  These can best be seen when the sky is clear and when it is very dark outside.

The North Pole

The North Pole is found in the Earth’s northern hemisphere.  This is where the magnetic field goes straight down or vertical.

The South Pole

The South Pole is found in the southern hemisphere and the line between the North and South Pole does not pass through the center of the Earth and does not go in a straight line.

Why is the Magnetic Field Important?

As we discussed earlier, the magnetic field helps to protect the Earth from things that are harmful such as particles, gases and radiation from the sun, but that is not all!  Other reasons that the Earth’s magnetic field is important is because:

  • People use the magnetic field to find their way using a compass.
  • Animals such as whales and birds use the magnetic field to help them find which way to go when they are migrating.
  • The magnetic field protects the Earth from solar wind.

Facts About the Earth’s Magnetism:

  • The magnetic field is tilted.
  • The magnetic field can move in different positions and this can make it stronger or weaker.
  • Both the North and the South magnetic poles move.
  • The magnetosphere also helps to protect the Earth from gases entering into the atmosphere.
  • Iron electrical currents are created in the core when the Earth spins.
  • The magnetosphere goes as far as 60,000 kilometers into space.
  • Compasses use the Earth’s magnetic field to help find directions.
  • The sun has a magnetic field that is much larger and stronger than the Earth’s magnetic field.
  • The Earth is like one big magnet.
  • The North Pole and the South Pole are magnetic.
  • The strongest magnetic force is found in a collapsed star which is also called a neutron star.
  • When the Earth spins, it causes there to be a magnetic pull.
  • During a magnetic reversal, the North and South pole will trade places.
  • The area between the North and South Poles is called a magnetic field line.
  • The magnetic poles are also called magnetic dip poles.
  • Animals that use the North and South Pole to migrate have built in magnetic maps that helps them to felt he magnetic particles.
  • Metals such as gold, silver and copper do not attract to magnets.
  • Magnets are attracted to iron, cobalt and nickel which help make up part of the inner Earth.
  • When something shows signs of magnetism, it will either pull an object closer or push the object away.

What Did You Learn?

  • What is the Earth’s magnetism?  
    The Earth’s magnetism is the part of the Earth that is like a magnet.  The magnetism starts at the core of the Earth and it also goes like a shield around the Earth, all the way into space.
  • What does the magnetic field do?  
    The magnetic field is like a shield that helps to protect the Earth from harmful things such as the radiation from the sun, particles and gases entering into the atmosphere.
  • Why is the magnetic field important?  
    The magnetic field is important because without it, it the Earth would get too hot and the planet would not be livable for animals, plants or humans.
  • What is another name for the area of the Earth that is like a shield and goes all the way into the atmosphere?  
    Another name for the magnetism that goes all the way into space is called the magnetosphere.
  • Where is the magnetic pull the strongest?  
    The magnetic pull is the strongest at the North Pole and the South Pole.  Even though the core is very magnetic, the strongest is still at the two poles.