Eddie Schwieterman
January 30, 2025
Zoom recording
Abstract:
The introduction of artificial, long-lived, highly potent greenhouse gases has been proposed as one method to terraform Mars in our Solar System, altering a climate that is too cold to support a global biosphere to one that can. Could current and future observatories identify such a “terraformed” world in a nearby exoplanetary system? This talk will examine the potential for a representative subset of these gases (CF4, C2F6, C3F8, SF6, and NF3) to generate atmospheric signatures detectable with JWST and future space-based telescopes such as the European Large Interferometer for Exoplanets (LIFE) mission concept. While these gases are present in Earth’s atmosphere today as passive byproducts of industrial processes in trace (and therefore weakly detectable) abundance, the purposeful alteration of planetary climate would necessitate quantities of these gases that would drastically impact the planet’s thermal infrared spectrum. We find that such signatures would rival or exceed those of traditional prospective biosignature molecules in the Mid-IR, such as CH4 and O3. The talk will broaden to examine the complementarity of searching for biosignatures and technosignatures, which exist on the same astrobiological continuum, and explore the near-term preparatory and precursor science required to aid these searches.