The magnetosphere is a region that surrounds the Earth's magnetic field and extends far out into space, some 36,000 miles, or possibly more than 1,000 times the Earth's radius, according to NASA's Cosmicopia website (see link in Resources). Two key components that form the Earth's magnetosphere are the Earth's magnetic field and the solar wind, a hydrogen/helium plasma streaming continuously outward from the sun into the solar system. Most particles from the sun carried in solar wind are prevented by the magnetosphere from bombarding the Earth. There are many more components that make up the Earth's magnetosphere, including the bow shock, magnetosheath, magnetotail and more, but it's safe to say that without the Earth's magnetosphere, dangerous particles from the sun and space radiation would pose a serious threat to life on Earth.
Trivia
The Earth has the strongest magnetosphere of all the rocky planets in our solar system. Venus and Mars, although rocky planets, do not have magnetospheres. In our solar system Mercury, Earth, and the Jovian (or gas) planets Jupiter, Saturn, Uranus and Neptune all have magnetospheres, as does the sun itself.
Fun Fact
Some particles do, however, enter the Earth's magnetosphere and travel along Earth's magnetic field lines to create the spectacular auroral light shows we know as the northern and southern lights.
Pole Flip-Flop
What we recognize as Earth's north and south poles reverse directions every few thousand years, as does the orientation of the magnetosphere. Evidence of this can be found in magnetic rock on the ocean floor. Are migrating birds and animals affected by this sudden flip-flop of poles? The jury is still out on that question.
Expert Insight
The magnetosphere was given its official name in 1958 by Tom Gold, an astronomy professor at Cornell University.
Effects
If you can imagine the bow of a ship speeding through water, you have a good idea of what the bow shock within the Earth's magnetosphere looks like and how it works. The collision of solar wind against the outer part of the Earth's magnetosphere creates an immense shock wave.
Tags: Earth magnetosphere, Earth magnetic, Earth magnetic field, magnetic field, solar system
