Researchers at the University of Colorado have discovered that a region around the planet, previously thought to be free of radiation, is actually awash with high energy particles. This so-called "safe-zone" sits in between the radiation-stuffed Van Allen belts. This region is normally shielded by the Earth's plasmasphere, but during the particularly intense solar storms last year, this was eroded somewhat and the "safe-zone" was flooded with ions. Some radiation still remains today, researchers have found. Last year's storms were unusually intense, but that doesn't mean the zone is safe. Once every 11 years, when solar activity peaks, radiation will be more than strong enough to flood the space between the Van Allen belts, and smaller peaks in the intervening years could also cause problems.

Source: The Register