Eleven billion miles from Earth, NASA's long-lived Voyager 2 probe, still beaming back data 41 years after its launch in 1977, has finally moved into interstellar space, scientists revealed Monday, joining its sister ship Voyager 1 in the vast, uncharted realm between the stars.
Voyager 2 moved past the boundary of the heliosphere, the protective bubble defined by the sun's magnetic field and electrically charged solar wind, on Nov. 5. The transition was marked by a sharp decline in the number of charged particles detected by the spacecraft's plasma science experiment, or PLS.
The instrument has not detected any signs of the solar wind since then....