Our Heliosphere and its Interstellar Interaction: A Solar Cycle of Global Observations and Discoveries by the Interstellar Boundary Explorer

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: David J. McComas is the Princeton University Vice President for the Princeton Plasma Physics Laboratory – a DOE National Laboratory, Professor of Astrophysical Sciences, and Associated Faculty in Mechanical and Aerospace Engineering. Prof. McComas received his B.S. Degree in Physics from MIT in 1980 and Ph.D. in Geophysics and Space Physics from UCLA in 1986, and is a Fellow of the American Physical Society (APS), American Geophysical Union (AGU), and the American Association for the Advancement of Science (AAAS). He has received numerous awards and accolades during his career including the European Geosciences Union’s 2022 Hannes Alfvén Medal, the Scientific Committee on Solar-Terrestrial Physics (SCOSTEP) 2022 Distinguished Scientist Award, AGU’s 2018 Eugene Parker Lecture, the 2014 COSPAR Space Science Award, NASA’s Exceptional Public Service Medal in 2015, and AGU’s James B. Macelwane Award in 1993. Most recently, Prof. McComas is the recipient of the 2023 Arctowski medal for his “seminal contributions through innovative mission and instrumentation development that have benefited and supported the entire scientific community and led ground-breaking observations, analysis, and discovery of fundamental physics of the heliosphere and the very local interstellar medium, the solar wind, and the Earth’s and other planetary magnetospheres”. Prof. McComas has invented a variety of instruments and missions for space applications and holds seven patents. He is an author of over 800 scientific papers in the refereed literature spanning topics in heliospheric, magnetospheric, solar, and planetary science as well as space instrument and mission development.

Poster