Approaching Solar System's Edge, Voyager Probes Detect A Foamy Sea of Magnetic Bubbles
A frothy moat, not a shield, protects us from cosmic rays For decades, scientists have believed there to be a fairly well-defined boundary at the edges of our solar system, a region where the sun appears only slightly brighter than the rest of the spangled heavens. But as they sail through the blackness, humanity's most-traveled spacecraft, the Voyager probes, have learned the lines are anything but clear. The edge of the solar system may not be a smooth edge at all, but a turbulent moat of roiling magnetic bubbles. Interstellar cosmic rays flowing toward us can get trapped in the moat, churning around in the foam, and they can hitch a ride on supercharged magnetic field lines, hurtling toward the sun - and toward the Earth. Put another way, the sun's enormous protective shield may not be a shield at all, but a permeable membrane that can be breached more easily than...