A new active period of Earth-threatening solar storms will be the weakest since 1928 and its peak is still four years away, after a slow start last December, predicts an international panel of experts led by NOAA's Space Weather Prediction Center. Even so, Earth could get hit by a devastating solar storm at any time, with potential damages from the most severe level of storm exceeding $1 trillion. NASA funds the prediction panel.

Solar storms are eruptions of energy and matter that escape from the sun and may head toward Earth, where even a weak storm can damage satellites and power grids, disrupting communications, the electric power supply and GPS. A single strong blast of solar wind can threaten national security, transportation, financial services and other essential functions.

The panel predicts the upcoming Solar Cycle 24 will peak in May 2013 with 90 sunspots per day, averaged over a month. If the prediction proves true, Solar Cycle 24 will be the weakest cycle since number 16, which peaked at 78 daily sunspots in 1928, and ninth weakest since the 1750s, when numbered cycles began.