After more than 40 years, the Voyager 2 spacecraft has crossed the boundary that marks the start of interstellar space.<br />NASA said on Tuesday that the spacecraft had entered the interstellar medium,...the region of space outside the boundary produced by wind streaming from the Sun.<br />Researchers says Voyager 2 detected abrupt differences in plasma density and magnetic particles upon crossing the heliopause.<br />It's just the second man-made object ever to depart the solar system after its twin the Voyager 1 entered interstellar space in November last year.<br />The Voyager twins were launched in 1977, and both are now traversing the Milky Way's interstellar medium.<br />
