Nasa, 7/11/13
It has long been assumed that our solar system, like a comet, has a tail. Just as any object moving through another medium – for example, a meteor traveling through Earth’s atmosphere – causes the particles to form a stream trailing off behind it. But the tail of our solar bubble, called the heliosphere, has never actually been observed, until now.
NASA’s Interstellar Boundary Explorer, or IBEX, has mapped the boundaries of the tail of the heliosphere, something that has never before been possible. Scientists describe this tail, called the heliotail, in detail in a paper published on July 10, 2013, in The Astrophysical Journal. By combining observations from the first three years of IBEX imagery, the team mapped out a tail that shows a combination of fast and slow moving particles. There are two lobes of slower particles on the sides, faster particles above and below, with the entire structure twisted, as it experiences the pushing and pulling of magnetic fields outside the solar system.