There's a boffin battle brewing at the fringe of the Solar System.
At issue is whether the venerable Voyager 1 spacecraft has left the region where Sol's electromagnetic winds blow, or is still in the tiny pocket of space we call home.
The “we're outta here” camp has penned a letter in The Astrophysics Journal titled “A porous, layered heliosphere” in its corner. The letter proposes a model of the heliopause, the region of space where Sol's solar wind is halted by interstellar space, as a “a porous, multi-layered structure threaded by magnetic fields.”
Author Marc Swisdak ,a University of Maryland physicist, told Reuters "We think that the magnetic field within the solar system and in the interstellar are aligned enough that you can actually pass through without seeing a huge change in direction.” That's important because last year Voyager spotted more cosmic rays from out there in the universe and fewer charged particles coming from the Sun, but didn't detect a change in the direction of magnetic fields.
The authors' theory means the change in local particles could be evidence the craft has left the solar system, without an accompanying change of direction for magnetic fields.
The crew of boffins responsible for the letter therefore suggest Voyager 1 left the solar system in June 2012, but we didn't realise it yet because of our imperfect understanding of how things go down out there.
In the other corner is NASA, which has popped out a statement saying “The model described in the paper is new and different from other models”. Those other models posit the Solar System as comprising a bubble within which magnetic fields move in the same direction – away from the Sun – and that once one leaves the solar system magnetic fields should change.
The statement goes on to say the newly proposed model “will become part of the discussion among scientists”. And Reg readers, we imagine. ®