THE UNIVERSE Some 18 billion kilometres from Earth’s surface is the ‘heliopause’ – the boundary between interstellar space and the huge gas bubble of electrically-charged particles that envelopes our Solar System, known as the heliosphere. The bubble is produced by solar winds constantly blowing particles out of the peripheral region, so protecting our Solar System from harmful radiation.
Only two craft have ever travelled beyond the Solar System shield of the heliosphere, and so the region remains relatively unexplored.
But now data from three
