This artist's concept shows NASA's twin Voyager spacecraft exploring a turbulent region of space known as the heliosheath, the outer shell of the bubble of charged particles around the sun in this handout provided by NASA. After 33, NASA's twin Voyager spacecraft are still going strong and sending home information. Voyager 1, launched in 1977 to explore the outer planets, has passed into a new region on its way out of th esolar system, scientists said March 20, 2013. [Photo/Agencies]