NASA mini-balloon mission maps migratory magnetic boundary

During the Antarctic summer of 2013-2014, a team of researchers released a series of translucent scientific balloons, one by one. The miniature membranous balloons - part of the Balloon Array for Radiation-belt Relativistic Electron Losses, or BARREL, campaign - floated above the icy terrain for several weeks each, diligently documenting the rain of electrons falling into the atmosphere from Earth's magnetic field.