heliosphere
First details of Voyager 2's entry into interstellar space revealed
Voyager 2's entry into the interstellar space occurred more than 18 billion kilometres from the Earth
NASA's Voyager 2 probe detects increase in cosmic rays as it approaches the heliosphere
Voyager 2, launched in 1977, will soon find out what the Solar System is like in, and beyond, the heliosphere
