The venerable Voyager 1 spacecraft seems to be a little closer to leaving our Sun's neighbourhood behind and entering interstellar space, says NASA.
The space agency has outlined three criteria that must be satisfied before Voyager will be deemed to have left the heliosphere, the first of which is detection of galactic cosmic rays. Voyager apparently detected a 25 per cent increase in such rays between January 2009 and January 2012, but recent readings apparently surpass that rate of growth and represent a “very rapid escalation” in galactic ray detection.
