The sun is headed toward the height of its 11-year weather cycle, leading to an increasing number of powerful solar flares recently.

The weather cycle is expected to hit its peak next year, and scientists are watching closely to see if the resulting flares could threaten earth.

Scientists warn the solar flares can disrupt satellites, airplane flights, and radio communications. The biggest concern is a possible threat to electric power grids.

Experts disagree on how long it might take to restore power if a severe flare knocked out an electrical system.

In 1859, a solar superstorm disrupted the world's telegraph system, causing fires at some telegraph stations.