Powerful geomagnetic storms, sparked by huge explosions of ultra-hot, roiling gas in the sun's atmosphere, can cause major disruptions to power grids in equatorial regions, research by Australian and US scientists has revealed. "Massive space weather events have crashed power grids across North America and Europe," says physicist Dr Brett Carter, of the RMIT SPACE Research Centre in Melbourne. "But our new research shows that, with little warning, smaller events may strike in equatorial regions more frequently and devastatingly than ever thought possible."