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The Mariner 10 encounter of Mercury provided data showing a strong interaction between the solar wind and the planet similar to a scaled down version of that producing the earth's magnetosphere. Some of the features observed in Mercury's night side magnetosphere suggest time-dependent processes occurring there. Interpreted as temporal events, these features bear striking resemblances to substorm phenomena in the earth's magnetosphere.
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Siscoe et al. (1975) studied this question.
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