关于这张图
Watching a BARREL balloon – and the instruments dangling below – float up over the SANAE IV research base in Antarctica. Credit: NASA --- In Antarctica in January, 2013 – the summer at the South Pole – scientists launched 20 balloons up into the air to study an enduring mystery of space weather: when the giant radiation belts surrounding Earth lose material, where do the extra particles actually go? The mission is called BARREL (Balloon Array for Radiation belt Relativistic Electron Losses) and it is led by physicist Robyn Millan of Dartmouth College in Hanover, NH. Millan provided photog…