It's been announced that Voyager 1 has left the solar system so many times, I didn't expect to read an article that said Voyager 1 hadn't even left the solar system at all yet!
Yeah, but none of those announcements have come from NASA. In fact, one of the recent solar system exit announcements triggered NASA to publish a press release [1] to let everyone know that Voyager 1 has, in fact, NOT left the solar system and all these announcements are wild speculation by people who don't directly work on the Voyager 1 team.
My understanding is that as soon as the magnetic field shifts, Voyager will be declared to have "left the solar system".
The solar wind has died down, the cosmic rays have increased (although they are unexpectedly coming from a single direction), and the magnetic field shift will be the third and final necessary event.
And they expect it soon (could be months or years).
"To all intents, cosmic rays arrive evenly from all directions in the sky, but this does not necessarily mean their sources are evenly spread around us. More likely, they are constantly deflected and scattered by magnetic fields in the galaxy, until any trace of their original motion is lost."[0]
A crude hypothesis would be that there's some sort of magnetic field that is directing them from a single location. Since we've never been this far before, its a pretty huge guess...
We don't know the edge yet. we are discovering it. It's a frontier. So how do you cross something that you don't even know the size of. All the announcements are of different definitions of the edge. There are many edges.
