Magnetic-bubble sea found at solar system’s edge

National Geographic : The heliosphere, our solar system’s magnetic barrier, was once thought to be a smooth shield but may instead be a sea of long magnetic bubbles that function more like a porous membrane than an impermeable shield. Galactic cosmic rays and energetic particles can become trapped in the membrane, but they will eventually make their way along solar magnetic field lines toward the Sun, writes Ker Than for National Geographic. The new theory is based on data from NASA’s twin Voyager spacecraft launched in 1977; both recorded dramatic variations in the amount of electrons they encountered as they traveled through the heliosphere. A NASA computer model suggests that the fluctuating readings may have been the result of the spacecraft entering and exiting magnetic bubbles, which would act as electron traps—causing higher than normal electron bombardment of spacecraft passing through them.