A weak spot in the Earth's magnetic field is growing over the South Atlantic Ocean, according to more than a decade's worth of satellite data collected by scientists.  The magnetic field surrounding Earth protects the planet from cosmic radiation and particles charged by the sun. Scientists believe it is generated by the outer core of the Earth, according to a news release from the European Space Agency . The ESA said the "global ocean of molten, swirling liquid iron" in that layer of the