Look at the picture on the immediate left here:
http://en.wikipedia.org/wiki/Earth's_magnetic_field
Also:
http://image.gsfc.nasa.gov/poetry/magnetism/magnetism.html
HOW IS THE EARTH'S MAGTISM USEFUL
thanks it helped me alot!!!!!!!!!!!
A PLANET WITH A FORCE OF GRAVITY 0.379 TIMES THAT OF EARTH
The Earth's magnetic field is indeed very useful for various reasons. Here are a few main ways in which the Earth's magnetism benefits us:
1. Navigation: One of the most crucial applications of Earth's magnetic field is in navigation. The field helps compasses and other navigation instruments to align and point towards the Earth's magnetic poles, thus assisting in determining directions accurately. This has been instrumental in exploration, maritime travel, and even modern-day satellite navigation systems.
2. Protection from Solar Radiation: The Earth's magnetic field acts as a shield, deflecting most of the harmful charged particles emitted by the Sun, known as solar wind. These particles are charged with high energy, and if they were to directly hit the Earth, they could damage electronic devices, disrupt communication systems, and pose health risks to living organisms. The magnetosphere, which is formed by the interaction between the solar wind and Earth's magnetic field, provides a protective barrier from the majority of these harmful particles.
3. Geology and Plate Tectonics: The study of Earth's magnetic field gives insights into the composition and movement of the Earth's interior. The magnetic properties of rocks, known as paleomagnetism, help geologists understand the past movements of tectonic plates. By analyzing the magnetic patterns in rocks, scientists can determine the historical positions and movements of continents and reconstruct the Earth's geological history.
4. Auroras: The interaction of charged particles from the Sun with Earth's magnetic field leads to the formation of spectacular natural light displays called auroras. These colorful light shows are most commonly seen near the Earth's poles and are a result of the charged particles entering the Earth's atmosphere along the magnetic field lines. Not only are they an incredible sight, but they also help scientists study and understand the behavior of plasma and magnetic fields in space.
These are just a few examples of how the Earth's magnetic field is useful to us. Its impact extends beyond what is mentioned here and continues to be an important area of scientific study and practical application.