Nasa craft is second to travel beyond heliosphere but will give most detailed data yet
Twelve billion miles from Earth, there is an elusive boundary that marks the edge of the sun’s realm and the start of interstellar space. Voyager 2, the longest-running space mission, has finally beamed back a faint signal from the other side of that frontier, 42 years after its launch.
The Nasa craft is the second ever to travel beyond the heliosphere, the bubble of supersonic charged particles streaming outwards from the sun. Despite setting off a month ahead of its twin, Voyager 1, it crossed the threshold into interstellar space more than six years behind, after taking the scenic route across the solar system and providing what remain the only close-up images of Uranus and Neptune.