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this video clip reveals the evolution of

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the sun's magnetism over the course of

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three solar cycles it uses data from the

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national solar observatory and from the

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esa nasa soho satellite

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we use special filters to measure the

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sun's magnetic field

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we can peel off a map of the magnetic

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field as the sun rotates

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new maps are obtained about every 27

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days

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the changes from one rotation to the

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next are dramatic

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magnetic fields and sunspots erupt in

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two bands on either side of the equator

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they leave behind magnetic elements

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which are transported across the surface

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by the flowing gases

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as each solar cycle progresses these

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bands drift toward the equator the

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magnetic elements themselves move to the

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right near the equator and to the left

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and forward at higher latitudes