@article{Habitability::7680,
      recid = {7680},
      author = {Warren, Alexandra Oksana},
      title = {Transient Terrestrial Planet Habitability: Insights from  Models and Measurements of Martian Craters and the  Evolution of Venus' Atmosphere},
      publisher = {University of Chicago},
      school = {Ph.D.},
      address = {2023-08},
      pages = {273},
      abstract = {If, when, and how other terrestrial planets were (or are)  habitable is one of the primary foci of planetary science.  The catalog of known planets around other stars has  exploded in recent years, and there is more data than ever  before that might be usable to determine whether any of  these exoplanets are habitable or inhabited. The  habitability of a planet through time -- where habitable  conditions are defined as those enabling surface liquid  water to be present on the planet's surface -- is the  product of many interconnected processes spanning the core  to the upper atmosphere. The abundance and resolution of  data available for Mars and Venus make these the only  planets besides the Earth where we can identify and  interpret the geologic imprints of these processes and  their resulting climates. In this thesis, I use Mars  topographic data, measurements of Venus' atmospheric  composition, statistical analysis, and numerical modeling  to integrate proxies for past conditions on both planets  into our understanding of their overall evolution. In the  first part of this thesis, I focus on the climate record  provided by martian geomorphology. In Chapter 2, I compare  the size distribution of ancient buried craters to impact  model results to constrain atmospheric pressure during one  of the wettest eras in Mars' history. In Chapters 3 and 4,  I use measurements and models of valleys exiting small,  relatively young craters with overspill channels but no  visible inlets to constrain the volume of water needed to  explain their formation under a range of climate  conditions, and infer that Mars' climate has been  ice-dominated but transiently and locally habitable for  billions of years. In the second part of this thesis, I  turn to the evolution of Venus as constrained by its modern  atmospheric composition. I present models of bulk  atmospheric composition and radiogenic argon degassing  which I use to explore the narrow range of parameter space  that enables a past habitable Venus to be reconciled with  the planet's present, and make recommendations for future  spacecraft observations that may reveal the likelihood of  clement past conditions on Earth's sister planet.},
      url = {http://knowledge.uchicago.edu/record/7680},
      doi = {https://doi.org/10.6082/uchicago.7680},
}