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How Do Magnetic Fields Protect Earth From Solar Wind?
地球磁场如何抵御太阳风？
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Earth’s molten iron core generates a powerful magnetic field extending far into space.
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This invisible shield deflects most charged particles streaming from the Sun’s outer atmosphere.
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Without it, solar wind would gradually strip away our atmosphere like Mars lost its.
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Some particles do enter near the poles, where field lines converge and guide them downward.
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There, they collide with atmospheric gases and create the shimmering auroras seen near Arctic and Antarctic circles.
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NASA satellites monitor real-time changes in magnetosphere shape during solar storms.
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During strong geomagnetic storms, induced currents can disrupt power grids and satellite operations.
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Animals such as sea turtles and migratory birds rely on this field for navigation across continents.
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The field strength fluctuates slowly over centuries and even reverses polarity every few hundred thousand years.
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Scientists map these variations using ancient lava flows that locked in magnetic orientation when cooling.