A NASA spacecraft paints a map of the solar system’s trailing edge.
Our sun, like the planets that circle it, is moving through space. About every 230 million years it completes one orbit around the center of the Milky Way galaxy. The entire solar system comes along for the ride, of course, residing within a massive, magnetic bubble called the heliosphere. Like a brightly lit comet, it was assumed the heliosphere has a leading head and a trailing tail region where streams of charged particles released from the sun meet interstellar space. But the tail section has never been observed, until now. NASA’s Interstellar Boundary Explorer, or IBEX, spacecraft has mapped the boundaries of the tail for the first time. By combining observations from the first three years of IBEX imagery, scientists found that the tail is made of fast- and slow-moving particles that are twisted by the pushing and pulling of magnetic fields outside the solar system. Watch the video to learn more.