Departmental Seminar - Prof. David McComas ( Thursday, July 28, 12 - 1pm Room B228 ΘΕΕ02)

Our Heliosphere and its Interstellar Interaction: A Solar Cycle of Global Observations and Discoveries by the Interstellar Boundary Explorer (IBEX) by Prof. David McComas (Princeton University).

Abstract: The supersonic solar wind and its embedded magnetic field continuously flow outward in all directions from the sun. This magnetized plasma inflates a bubble – the heliosphere – in the very-local interstellar medium (VLISM). The Interstellar Boundary Explorer (IBEX) mission launched in late 2008 and provided the first ever 3-D global images of our heliosphere through observations of Energetic Neutral Atoms (ENAs). These ENAs arise from charge exchange between ions in the subsonic heliosheath region and beyond with low energy interstellar neutral atoms drifting in from the VLISM. Now spanning more than a full solar cycle, IBEX’s all-sky maps of ENAs and other observations uniquely allow us to study the global outer heliosphere and its evolving interstellar interaction. Insights from IBEX, in concert with in situ observations by the two Voyager spacecraft, which were transiting two different trajectories through the outer boundaries of the heliosphere contemporaneously with IBEX, have led to a true scientific revolution in our understanding of the outer heliosphere and its interstellar interaction. This seminar will summarize some of the many discoveries and “firsts” from the IBEX mission and their implications for the outer heliosphere and VLISM. Finally, we will also look forward to the promise of the follow-on, and even more advanced, Interstellar Mapping and Acceleration Probe (IMAP) mission, which is under development and slated to launch in 2025.

About the speaker: Prof. McComas is the Princeton University Vice President for the Princeton Plasma Physics Laboratory and Astrophysical Sciences Professor. He also serves on the National Academies Space Studies Board and the Brookhaven National Laboratory Science Associates Boards of Directors. Prof. McComas is a fellow of the American Physical Society (APS), American Geophysical Union (AGU), and the American Association for the Advancement of Science Award (AAAS). He has received numerous awards and accolades, including the 2014 COSPAR Space Science Award, NASA's Exceptional Public Service Medal in 2015, and AGU's James B. Macelwane Award in 1993.