Institute for Advanced Study/Princeton University Joint Astrophysics Colloquium

DATE & TIME CHANGED! The Interstellar Boundary Explorer (IBEX) was the first mission to explore the global heliosphere and in concert with Voyager 1 and Voyager 2 is discovering a fundamentally new and uncharted physical domain of the outer heliosphere. IBEX observes enhanced Energetic Neutral Atoms emission from a narrow “ribbon” likely centered on the local interstellar medium (LISM) magnetic field direction. The enigmatic IBEX ribbon was an unanticipated discovery demonstrating that much of what we know or think we understand about the outer heliosphere needs to be revised. Further, IBEX has improved knowledge of the local interstellar velocity based on interstellar atom measurements. These new determinations are found to be consistent with the interstellar modulation of high energy (TeV) cosmic rays revealed in global anisotropy maps of ground-based high-energy cosmic-ray instruments (Milagro, Asγ and IceCube). The next quantum leap enabled by the Interstellar Mapping and Acceleration Probe (IMAP), recommended as the next Solar Terrestrial Probe Mission by the Solar and Space Science Decadal Survey, will open new windows on the frontier of Heliophysics at a time when the space environment is rapidly evolving. IMAP, like ACE before it, will be a keystone of the Heliophysics System Observatory by providing comprehensive cosmic ray, energetic particle, pickup ion, suprathermal ion, neutral atom, solar wind, solar wind heavy ion, and magnetic field observations to diagnose the changing space environment and understand the fundamental origins of particle acceleration. In this talk, we will review recent discoveries of IBEX and their relation to measurements by Voyager 1 and Voyager 2. We will discuss new analyses of IBEX measurements of interstellar neutral matter, which reveal the influences of interstellar structure influenced by the external interstellar magnetic field.