Voyager has made a surprising discovery 35 years after its launch and Voyager has now traveled 11 billion miles (18 billion kilometers) away from the Sun, which is 122 times the distances from the Earth to the Sun. Yet it takes only 17 hours for its radio signal to reach us.
Earlier this year a surge in a key indicator fueled hopes that the craft was nearing the so-called Heliopolis which marks the boundary between our solar system and outer space.
But instead of slipping away from the bubble of charged particles the Sun blows around itself, Voyager encountered something completely unexpected.
“Although Voyager 1 still is inside the Sun’s environment, we now can taste what it’s like on the outside because the particles are zipping in and out on this magnetic highway,” said Edward Stone, a Voyager project scientist based at the California Institute of Technology, Pasadena.
“We believe this is the last leg of our journey to interstellar space. Our best guess is it’s likely just a few months to a couple years away. The new region isn’t what we expected, but we’ve come to expect the unexpected from Voyager.”
Scientists began to think it was reaching the edge of our solar system two years ago when the solar winds died down and particles settled in space the way they would in a swamp.
An increase in the number of cosmic rays in May also led them to believe Voyager had approached interstellar space.
NASA has described Voyager 1 and its companion Voyager 2 as “the two most distant active representatives of humanity and its desire to explore.”
The scientists controlling Voyager 1 — whose 1970s technology gives it just a 100,000th of the computer memory of an eight-gigabyte iPod Nano — decided to turn off its cameras after it passed Neptune in 1989 to preserve power.
Assuming the craft continues to function normally, they will have to start turning off other on-board instruments from 2020, and it is expected to run out of power completely in 2025.