The worst solar-storm season in half a century starts this year. These fiery explosions-which unleash as much energy as a billion hydrogen bombs-could, under the right conditions, black out cities and fry satellites. But new solar scopes can give us advance warning
Last December, a colossal wave swept across the entire solar surface within minutes, bulldozing everything in its path. The rare tsunami-like shockwave formed on the heels of a major flare that erupted from an Earth-size sunspot 15 minutes earlier. Though that storm didn't have a major impact on Earth, we aren't always so lucky.