Latest Results from Voyager 1 Observation in the Very Local Interstellar Medium


Abstract

  • Voyager 1 (V1) traveled into a region of space dominated by interstellar particles and a high magnetic field strength in August 2012. Whether V1 crossed a traditional heliopause or some other sort of "heliocliff," is not universally agreed upon, but the dramatic disappearance of heliospheric particles that accompanied the other changes leaves no doubt as to the importance of this boundary. While both spacecraft were within the heliosheath, from 2007 to 2012, Voyager 2 (V2) passed back and forth across the boundary between the unipolar and sectored heliosheath. When V2 was inside the sector zone, ions and electrons spanning four orders of magnitude in gyroradius all coherently increased intensity by roughly an order of magnitude compared to the intensities outside the sector region. Voyager 1, during this period, remained almost continually within the sectored heliosheath, with high, steady intensities to match. We present observations from the Low Energy Charged Particle experiment at these two boundaries and highlight their relationship to the heliosphere as a whole.