The Solar Wind Interaction with Pluto's Escaping Atmosphere

Abstract:

NASA's New Horizons mission presents the opportunity to obtain in-situ measurements of the solar wind interaction with Pluto. Ionization of Pluto’s escaping atmosphere suggests the interaction with the solar wind will be similar to that of a comet. In contrast to cometary interactions that have been measured relatively close to the Sun, the weak magnetic field and tenuous density of the solar wind in the outer heliosphere imply that the interaction with Pluto’s atmosphere will include significant kinetic effects and be highly asymmetric. Understanding these interactions will expand our knowledge of the astrophysical processes affecting these bodies and that part of the solar system. The SWAP instrument on New Horizons will make measurements of the solar wind deceleration and deflection due to the interaction with Pluto. The PEPPSI instrument will measure energetic particles produced in the interaction region. SWAP will also measure solar wind conditions at large distances from the Sun and measure the effects of pickup protons from the interstellar medium in the distant heliosphere.