Our planetary neighbors hold important clues about the universal limits planetary evolution and atmospheric escape place on habitability. In my work, I take a whole-atmosphere approach to understanding how these objects have evolved, combining ab initio computational modeling, spacecraft mission data analysis, and instrument and mission development to propel the field forward. For Mars and Venus, work done by my group has revealed the dominant mechanism of hydrogen (water) escape currently active at both planets— at Mars, using optically thick radiative transfer analysis of UV remote sensing data combined with photochemical modeling; and at Venus, using comprehensive modeling of nonthermal photochemical escape processes and reanalysis of Pioneer Venus Orbiter in situ data. At Mars, my group has recently begun to use rare observations of aurora that indicate direct solar wind precipitation into the thermosphere to understand how the induced magnetosphere responds to radial (flow-aligned) interplanetary magnetic field conditions, and what lessons such conditions hold for planetary evolution in general. For both planets, I am currently developing a new UV spectrometer design that would improve planetary mission FUV spectral resolution by a factor of 1000 while retaining existing instrument sensitivity. I also PI a mission proposal team developing a new Venus magnetosphere – ionosphere – thermosphere coupling mission, responsive to the recent Heliophysics Decadal, that would use Venus as a laboratory to understand fundamental heliophysics processes. In all of these efforts, my work is and will continue to be amplified by a broad and talented group of students, postdocs, and research scientists, whose work I will highlight.
The Physics Frontiers Centers (PFC) program supports university-based centers and institutes where the collective efforts of a larger group of individuals can enable transformational advances in the most promising research areas. The program is designed to foster major breakthroughs at the intellectual frontiers of physics by providing needed resources such as combinations of talents, skills, disciplines, and/or specialized infrastructure, not usually available to individual investigators or small groups, in an environment in which the collective efforts of the larger group can be shown to be seminal to promoting significant progress in the science and the education of students. PFCs also include creative, substantive activities aimed at enhancing education, broadening participation of traditionally underrepresented groups, and outreach to the scientific community and general public.