Recent Observations of Galactic Cosmic Rays from Voyagers 1 and 2

COFFEE_KLATCH  · Invited

Abstract

The twin Voyager spacecraft were launched in 1977 and are still returning data after 40 years in space. Voyager 1 has crossed into the local interstellar medium (LISM) and is returning measurements of the low-energy parts of the galactic cosmic ray (GCR) spectra that are free of solar modulation effects for the first time. Voyager 2 is still in the inner heliosheath but appears to be rapidly approaching the heliopause. We will report on recent observations from the two spacecraft, including: the gradient of GCRs in the LISM; the GCR energy spectra in the LISM of elements from H through Ni, as well as some isotopes and electrons; and GCR electron observations from Voyager 2 that yield rough estimates of when it might cross the heliopause.

*This research was supported by NASA Grant NNN12AA01C

Authors

  • A.C. Cummings

    • Caltech
  • E.C. Stone

    • Caltech
  • B.C. Heikkila

    • Goddard Space Flight Center
  • N. Lal

    • Goddard Space Flight Center
  • W.R. Webber

    • New Mexico State University