"The new 11-year cycle, called Solar Cycle 24, is expected to build gradually, with the number of sunspots and solar storms reaching a maximum by 2011 or 2012, though devastating storms can occur at any time.
During a solar storm, highly charged material ejected from the sun may head toward Earth, where it can bring down power grids, disrupt critical communications, and threaten astronauts with harmful radiation.
Storms can also knock out commercial communications satellites and swamp GPS signals. Routine activities such as talking on a cell phone or getting money from an ATM machine could suddenly halt over a large part of the globe."
