A solar storm is racing toward Earth this weekend, but scientists say not to worry.
The blast of charged solar particles was due to arrive on Saturday morning and last through Sunday as it slams into 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.
Scientists said they had notified power grid operators, airlines and other potentially concerned parties.
"We don't see any ill effects to any systems,'' said forecaster Joe Kunches at the US Space Weather Prediction Center in Colorado.
There's a bright side to stormy space weather: It tends to spawn colorful northern lights as the charged particles bombard Earth's outer magnetic field. Shimmering auroras may be visible at the United States-Canada border and northern Europe this weekend, Kunches said.
The storm began on Thursday when the sun unleashed a massive flare that hurled a cloud of highly charged particles racing toward Earth at 3 million mph (4.8 million kph).
It was the sixth time this year that such a powerful solar outburst has occurred. None of the previous storms caused major problems.
In severe cases, solar storms can cause power blackouts, damage satellites and disrupt GPS signals and high-frequency radio communications. Airlines are sometimes forced to reroute flights to avoid the extra radiation around the north and south poles.
In 1989, a strong solar storm knocked out the power grid in Quebec, causing six million people to lose electricity.
Juha-Pekka Luntama, a space weather expert at the European Space Agency, said utility and navigation operators "will certainly see something, but they will probably find ways to deal with any problems.''
The storm is part of the sun's normal 11-year cycle of solar activity, which is supposed to reach peak storminess next year.
NASA's Solar Dynamics Observatory captured Thursday's flare, wowing scientists with images of the massive ouburst.