The Voyager team infers this region is still inside of our heliosphere because the direction of the magnetic field has not changed. The direction of this field is expected to change when Voyager goes into interstellar space.
'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, 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.'
Moving at 10.5 miles per second, the space probe is the most distant man-made object from Earth.
The space craft has been in operation for 35 years and receives regular commands and transmits data back to the Deep Space Network."