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The webinar recording is now available. Please click here to access the recording.
On April 28, the NExSS webinar series continued with Adrian Lenardic (Rice University) and Hilairy Hartnett (SESE/ASU) discussing habitability and biosignatures.
Prof. Adrian Lenardic led a metacognitive discussion on what habitability is and how we might measure it using Earth and Venus as framing devices. In bulk properties such as size and distance from the host star, Earth and Venus are similar, yet one is habitable and the other decidedly not. Modelers can use these differences to categorize planets into regimes, a technique common in planetary science. But, Dr. Lenardic says, “they can misinform us about what habitability really is.”
Prof. Hilairy Hartnett presented the importance of phosphorus in biological processes, and discussed what phosphorus means in the context of searching for biosignatures on water worlds. Life on Earth heavily relies on carbon, nitrogen, and phosphorus, and it turns out phosphorus is the limiting factor in searching for potentially habitable systems. Too much water is a potential problem for detecting life on an exoplanet because this limits the introduction of phosphorus to the environment, dropping oxygen production rates to abiotic levels, so we do not recognize the planet as habitable.