Earths Magnetic Field

Earths Magnetic Field

The earth's magnetic field is an invisible layered shield around earth's atmosphere it protects us and the atmosphere from dangerous particles coming from space. However, it does not stop things such as gamma rays. Without it we would not be alive, but how does it "stop" these particles?

Let's start with looking at how it reacts to solar winds. The solar wind is created when the temperature of the outer layer of a star reaches 1.1 million degrees this temperature causes the particles to move at extremely fast speeds. Because of this incredibly increased movement, the suns gravity can not contain all of them so a lot of them break off and begin travelling in random directions creating a "wind". These groups of particles are called plasma. The plasma radiate extremely deadly amounts of radiation. When these particles hit the earth they would pretty much end life as we know it. There could be a few survivors and a possible rebuild but most of all life on earth would be destroyed. However, our magnetic field stops these particles from hitting us.

The solar wind mainly consists of two groups of particles, Alpha particles and Beta particles. Alpha particles are made when the nucleus of an unstable radioactive atom let's 2 protons and neutrons go. These two protons and neutrons then form the alpha particle. This process can also change the element of the unstable atom, for example, Plutonium which has 94 protons will become Uranium with 92 protons. Alpha particles are very weak in fact they can't even penetrate paper! Beta particles are made from beta decay. There are two types of beta decay one being beta minus decay and the other being beta plus decay. Beta minus decay is when a neutron in the nucleus of an unstable atom turns into an electron, proton and Antineutrino. The electron and Antineutrino fly away creating a beta particle while the nucleus gains a proton and changes elements based on that. Eg: Carbon with 6 protons can turn into nitrogen with 7 protons. Beta-decay plus is mostly the same except the atoms end with one less proton also changing its element. Once these particles in the solar wind hit a magnetic field they are each attracted to different parts of the field. There are positive parts of the field and negative parts of the field, Alpha particles are attracted to the negative parts of the field whereas beta particle are attracted to the positive part of the fields.

Every now and then (more common when the sun has reached a solar maximum in its 11-year cycle) the sun will shoot a larger burst of plasma, this is known as a CME or Coronal Mass Ejection. When a normal solar wind and a CME combine it can cause massive damage to the planet. In fact, it pushes our magnetic field on the backside causing our field to sometimes push together in parts. Charged particles would then stream towards the magnetic poles creating an Aurora Borealis in the upper regions.

Many planets do not have a magnetic field like we do, therefore solar winds and CME's ravage their planet leaving them mostly barren. It is believed this is because of the core of each floating rock. It is believed that in the middle of the earth is a solid core made mostly of iron. This iron is as hot as the surface of the sun but the pressure of gravity down there keeps it from melting. The deeper you go into the earth the bigger the pressure, this is a big reason why we haven't explored all the ocean or gone too deep into the ground. Surrounding this is the outer core which is made of iron and other metals but the pressure is too low to keep it solid therefore the metals there are liquid. Despite the iron being liquid it still conducts the flow of electrons that make up electrical current very well. This flow then creates a magnetic field around the earth.