Exploring the Most Distant Parts of our Space Neighborhood

Gary P. Zank (Department of Space Science, University of Alabama in Huntsville)

Although we’re still exploring the inner atmosphere of our Sun, attention is beginning to turn again to the most distant regions of the heliospheric bubble within which we reside. This is being driven by two exciting events: the first is that the New Horizons spacecraft is rapidly approaching the first of the large-scale boundaries, the heliospheric termination shock, discovered originally by the two Voyager spacecraft. What will the New Horizons instrumentation observe and what to we anticipate seeing? The second is the expected launch in late 2025 of a new NASA mission, Interstellar Mapping and Acceleration Probe (IMAP). IMAP will make in situ measurements of the space environment at 1 astronomical unit (au) and remote measurements of energetic neutral atoms created in the boundaries and beyond of the heliosphere. We take a gentle and perhaps slightly irreverent walk through the physics of the distant heliosphere and what we might expect from these missions.