Space Science Reviews

, Volume 146, Issue 1, pp 235-273

Open Access This content is freely available online to anyone, anywhere at any time.

The Galactic Environment of the Sun: Interstellar Material Inside and Outside of the Heliosphere

  • P. C. FrischAffiliated withUniversity of Chicago Email author 
  • , M. BzowskiAffiliated withSpace Research Centre PAS
  • , E. GrünAffiliated withMax-Planck-Institut fuer Kernphysik
  • , V. IzmodenovAffiliated withMoscow State University and Space Research Institute RAS
  • , H. KrügerAffiliated withMax-Planck-Institut fuer Sonnensystemforschung
  • , J. L. LinskyAffiliated withUniversity of Colorado and NIST
  • , D. J. McComasAffiliated withSouthwest Research Institute
  • , E. MöbiusAffiliated withUniversity of New Hampshire
  • , S. RedfieldAffiliated withWesleyan University
    • , N. SchwadronAffiliated withUniversity of ChicagoBoston University
    • , R. SheltonAffiliated withUniversity of ChicagoUniversity of Georgia
    • , J. D. SlavinAffiliated withUniversity of ChicagoSAO-Harvard
    • , B. E. WoodAffiliated withUniversity of ChicagoNaval Research Lab


Interstellar material (ISMa) is observed both inside and outside of the heliosphere. Relating these diverse sets of ISMa data provides a richer understanding of both the interstellar medium and the heliosphere. The galactic environment of the Sun is dominated by warm, low-density, partially ionized interstellar material consisting of atoms and dust grains. The properties of the heliosphere are dependent on the pressure, composition, radiation field, ionization, and magnetic field of ambient ISMa. The very low-density interior of the Local Bubble, combined with an expanding superbubble shell associated with star formation in the Scorpius-Centaurus Association, dominate the properties of the local interstellar medium (LISM). Once the heliosphere boundaries and interaction mechanisms are understood, interstellar gas, dust, pickup ions, and anomalous cosmic rays inside of the heliosphere can be directly compared to ISMa outside of the heliosphere. Our understanding of ISMa at the Sun is further enriched when the circumheliospheric interstellar material is compared to observations of other nearby ISMa and the overall context of our galactic environment. The IBEX mission will map the interaction region between the heliosphere and ISMa, and improve the accuracy of comparisons between ISMa inside and outside the heliosphere.


Interstellar material Heliosphere Local bubble