WASHINGTON (AP) - The largest solar storm in five years has engulfed Earth, but scientists say the planet has lucked out so far.

The storm arrived more peacefully Thursday morning than it could have. Scientists say that could change as the storm spends the day shaking the planet's magnetic field. It could disrupt technology but also spread colorful Northern Lights.

The storm started with a massive solar flare earlier in the week and grew as it raced outward from the sun. The storm arrived at Earth about 6 a.m. Eastern.

So far officials say there have been no reports of problems with power grids, GPS, satellites or other technologies that are often disrupted by solar storms.

Officials say North American utilities are monitoring for abnormalities on their grids and have contingency plans.

Astronomers say the storm is part of the sun's normal 11-year cycle, which is supposed to reach peak storminess next year.