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.
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