An Interdisciplinary (Preliminary) Understanding of Planetary Evolution

The key to finding life on an exoplanet lies within the atmospheres of extrasolar planets, which have just recently become accessible to chemical analysis. The only way to detect a true ‘biosignature’—a definitive marker for life—is to rule out all abiotic processes that could lead to a ‘false positive.’ Thick atmospheres enshroud the interiors of the most common types of rocky planets. These planets’ geologic evolution is inextricably tied to their atmospheres in ways we don’t yet fully understand. To reveal the intricacies of this connection and ultimately open the door to the reliable detection of life beyond Earth we need a diverse team, access to facilities, and resources that will catalyze new discoveries and advance a new scientific paradigm. To accurately use planetary atmospheres as a proxy for life, establishing a baseline for a planet is critical. Atmospheres are complex, both physically and chemically. They are modified not only by the stellar insolation they receive from above but by the rocky surface below. The interiors and atmospheres of rocky planets interact initially during the magma ocean stage, that could last for a billion years, and then more slowly due to weathering, volcanism, and subduction. Our AEThER team has begun a coordinated scientific effort employing experimental, theoretical, and empirical approaches to address challenging yet fundamental questions, including: What is the principal control on planetary atmospheres from accretion until the time life begins to modify the signal? How sensitive is atmospheric chemistry to interior chemistry? This talk will discuss our current findings as well as our future directions.