A new model of the sun's heliosphere. Now granted, there is some minor dispute as to whether or not Voyager 1 actually made it to interstellar space yet.. but the model makes sense. http://www.sciencedaily.com/releases/2015/02/150219115636.htm You got to think, the sun is constantly replenishing the heliosphere.. which is moving through our galaxy. It almost seems like common sense that as it moved along, excess would trail behind it. Everything that has gravitational fields seems to have 2 poles.. so it makes sense that there would be 2 trails. If you try to imagine it moving along.. seems kind of cool. "Bubbles" of solar plasma that break off the ends of the trails.. surrounded by interstellar medium and dissipate into it over time.