# Current into ground

The Earth's atmosphere is constantly bombarded by cosmic ray protons that originate somewhere in space. If the protons all pass through the atmosphere, each square meter of the Earth's surface would be hit by protons at an average rate of $$1500 \text{ protons/sec}.$$ If the total surface area of the Earth is $$5 \times 10^{14} \text{ m}^2,$$ what is the electric current intercepted by the Earth?

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