Episode 110: Bayesian Biosignatures

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This week, Shashank, Cole and Cormac discuss a concept that has come up on many an ASB episode past: Bayesian statistics. They start by trying to wrap our heads around what a probability really means. Cole introduces us to a recent and attention-grabbing paper on a potential biosignature in the atmosphere of an exoplanet, with lots of statistics along the way. Then, Cormac brings up some counterpoints to this detection. They debate what it would take—statistically and scientifically—for a detection of biosignatures to cross the line from intriguing to compelling.

New Constraints on DMS and DMDS in the Atmosphere of K2-18 b from JWST MIRI

https://iopscience.iop.org/article/10.3847/2041-8213/adc1c8

Are there Spectral Features in the MIRI/LRS Transmission Spectrum of K2-18b?

https://arxiv.org/abs/2504.15916

Insufficient evidence for DMS and DMDS in the atmosphere of K2-18 b. From a joint analysis of JWST NIRISS, NIRSpec, and MIRI observations

https://arxiv.org/abs/2505.13407

Space Sound:

https://www.youtube.com/watch?v=hGdk49LRB14