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Physics

Magnetotail Reconnection and Geomagnetic Substorms

Quick fact

A single substorm can release energy equivalent to tens of thousands of lightning bolts, and the entire process—from magnetic energy buildup to explosive release—can unfold in under an hour.

Why this is interesting

Every few hours, Earth's magnetic tail snaps like a rubber band, firing particles toward our planet and lighting up the polar skies. What causes this explosive reset?