Unexpected observations by NASA’s Voyager 1 spacecraft have astronomers once again revising their theories about the radial extent of the heliosheath – the heated outer shell of the solar system. Recent data from the spacecraft have shown a gentle decrease in the velocity of the solar wind at the heliopause – the outer boundary of the heliosheath – not the abrupt discontinuity predicted by current theories. Also, scientists looking at other data from both Voyager 1 and Voyager 2 have found that the magnetic field in the heliosheath is a tumultuous foam of magnetic bubbles, as compared to the graceful arcs of magnetic field lines they had expected.
Watch the animation – ScienceCasts: Big Surprise
Categories: Astronomy, Science and Technology, Technology