How is IBEX important to NASA?

Challenge 2: Understanding heliospheric structure, the distribution of magnetic fields and matter throughout the solar system, and the interaction of the solar atmosphere with the local interstellar medium. "The boundary between the solar wind and the local interstellar medium (LISM) is one of the last unexplored regions of the heliosphere. Very little is currently known about this boundary or the nature of the LISM that lies beyond it. … certain aspects of these regions can be studied by a combination of remote sensing and in situ sampling techniques. This investigation could be accomplished by a mission … to obtain energetic neutral atom images … of the heliospheric boundary. Such a mission is gauged to be feasible within the resource limits of the Explorer program …"

"An entirely new level of information on the interface between the heliosphere and the LISM is required. … Imaging of the outer boundaries ~100 AU away can also be done from orbits near 1AU. … Remote-sensing techniques such as energetic neutral atom (ENA) imaging of energetic protons … near the termination shock and in the heliosheath should provide additional diagnostics of the interfaces with the galaxy."

Objective 5.13: Understand the changing flow of energy and matter throughout the Sun, heliosphere, and planetary environments. "We also will show how the outer layers of the solar atmosphere are energized, and we will track the causes of terrestrial disturbances … Even the interstellar gas that enters the solar system can be analyzed using remote sensing."