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| Magnetic field of Earth protecting from Solar wind |
Everybody is usually familiar with word ‘Magnet’, magnet is a small
piece of rock or metal that can attract many types of metals like iron, cobalt
and nickel. The range of application of magnet is also very wide from compass to
electronic devices. The magnet creates some effects in the surrounding space
that can affect other magnets and metal, this effect is called magnetic field.
Magnet interacts with other material through this magnetic field.
But there magnetic field is very important in the development and
protection of life on Earth. One cannot imagine life without
magnetic field of Earth. Earth is also a source of huge magnetic field that extends from core to
the outer space where it interacts with solar wind. It can be assumed that
there exists a big magnet in the crust of Earth placed along North-South
direction. The source of this magnetic field is motion of molten alloys in the
core of Earth.
This magnetic field is tilted by 11 degree from the axis of rotation
of Earth. The direction of this magnetic field changes with time but at very
slow rate that we can use our compass in this magnetic field for navigation. It
takes around hundred thousand years to interchange the North and South Pole.
But the question why is this magnetic field so important in protection
of life?
This magnetic field is like walls of home that can protect us from
various types of cosmic radiations and solar winds. Solar wind consists of high
energy particle that travels at tremendous speed and have such a high energy
that they swipe off the upper part of atmosphere. In the absence of magnetic
field Mars had to lose large fraction of atmosphere in the past. Even they
can remove the ozone layer that protects us from harmful ultraviolet radiations
that have ability to cause skin cancer.
Magnetic field of Earth traps the high energy particle
by applying magnetic force that causes particle to move in spiral path towards
the pole. The entire particles moves along magnetic lines and accumulates in
the atmosphere of poles where they can cause auroras. These Solar winds
can also interfere with radio transmission and satellites.
Cosmic radiation are usually high energy particles that are emitted from
other stars and explosion, it may consist of high energy electromagnetic
radiation like X rays and gamma rays. The high energy particles which have high
mass also are very dangerous for life, they can penetrate anything. Protection
from such heavy and high energy particles requires a concrete wall of around 6
foot that’s why travel through spaceships in outer space is full of danger.
But we are lucky that we have magnetic field of Earth which can
protect us from such cosmic radiations.
When solar winds collide with our magnetic field it usually deforms its
shape by large amount. In spite of such large jerks it is still protecting us.