Plasma Near Earth
In the early years of the 20th century, Kristian Birkeland first hypothesized and later observed the filamentary currents high above the earth that make the aurora glow. The confirmation of that early observation by satellites in the 1970’s showed that currents in space moved along magnetic field lines. Today, detailed studies of near-earth plasma continue to reveal phenomena that, like the Birkeland filaments, can be applied to plasma in the laboratory, including those in fusion research.