THE EARTH'S LIFE SAVING MAGNETIC FIELD´╗┐

Tom and Husam

When charged particles hit the earth, since they are charged they will repel from earth's magnetic field. Earth's magnetic field is very important. Without it life on the planet would not be possible because there would be no atmosphere and radiation and gamma rays would destroy human life. This is what happened on Mars. Scientists say that it was possible that life existed on Mars and the magnetic field was destroyed therefore making it impossible for life to exist on Mars.

Earth's Magnetic Field


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Earth's magnetic field deflecting solar particles

The magnetic field surrounds and permeates the Earth. It is the presence of this field that causes compass needles to line up in a north-south direction. The origin of the Earth's magnetic field is poorly understood at the present time.
The Earth is largely protected from the solar wind, a stream of energetic charged particles emanating from the Sun, by its magnetic field, which deflects most of the charged particles. Some of the charged particles from the solar wind are trapped in the Van Allen radiation belt. A smaller number of particles from the solar wind manage to travel, as though on an electromagnetic energy transmission line, to the Earth's upper atmosphere and ionosphere in the auroral zones. The only time the solar wind is observable on the Earth is when it is strong enough to produce phenomena such as the aurora and geomagnetic storms. Bright auroras strongly heat the ionosphere, causing its plasma to expand into the magnetosphere, increasing the size of the plasma geosphere, and causing escape of atmospheric matter into the solar wind. Geomagnetic storms result when the pressure of plasmas contained inside the magnetosphere is sufficiently large to inflate and thereby distort the geomagnetic field.


The solar wind is responsible for the overall shape of Earth's magnetosphere, and fluctuations in its speed, density, direction, and entrained magnetic field strongly affect Earth's local space environment. For example, the levels of ionizing radiation and radio interference can vary by factors of hundreds to thousands; and the shape and location of the magnetopause and bow shock wave upstream of it can change by several Earth radii, exposing geosynchronous satellites to the direct solar wind. These phenomena are collectively called space weather. The mechanism of atmospheric stripping is caused by gas being caught in bubbles of magnetic field, which are ripped off by solar winds. Variations in the magnetic field strength have been correlated to rainfall variation within the tropics.

How Earth's magnetic field works and when it is most effective

Earth's magnetic field protects us from solar winds and knowledge on the subject helps us to predict when solar storms are to be severe.
Sources:
http://answers.yahoo.com/question/index?qid=20110317142247AArHyVB
http://csep10.phys.utk.edu/astr161/lect/earth/magnetic.html
http://www.universetoday.com/27005/earths-magnetic-field/
http://science.nasa.gov/science-news/science-at-nasa/2001/ast25jan_1/