The blast of charged solar particles was due to arrive Saturday morning and shake Earth's magnetic field. Space weather forecasters say it will be a minor event and they don't expect disruptions to power grids or communications systems.
The storm began Thursday when the sun unleashed a huge flare that sent a stream of particles speeding toward Earth at 3 million mph.
There's a bright side to stormy space weather: It tends to create colorful northern lights. Scientists say shimmering colorful auroras may be visible at the United States-Canada border and northern Europe this weekend.