1 Image Credit: Martin Vargic 2 PEACH: The Physiology-Exoplanet Astroecological model for Characterizing Habitability
Alma Y. Ceja NASA MIRO FIELDS Fellow Planetary Research Laboratory University of California, Riverside
3 Questions:
1. What kinds of planets and stars produce habitable conditions? 2. What types of organisms could a “habitable” exoplanet sustain? 3. Which biosignatures might be observable from inhabited exoplanets?
4 Ecological Modeling
Predicted Distribution Environmental Data
Physiological Data
5 ROCKE-3D
• Fully coupled and dynamic oceanic-atmospheric climate model • Simulates atmospheric chemistry, aerosols, the carbon cycle, and other tracers • Has been used to model Earth, Mars, Venus, TRAPPIST-1, and Proxima Centauri b
Image Credit: Kaitlin Alexander and Steve Eastbrook 6 Rule-based modeling
7 Thermal Performance Curves
Schulte 2014 8 The Biokinetic Spectrum of Temperature for Life on Earth • Describes maximum and minimum thermal growth rate limits for 1627 organisms • Data is inclusive of all three Domains, all six Kingdoms, and forty-three of the fifty-five phyla • Data is made available and features individual thermophysiology data
Corkrey et al. 2016 9 Thermal Performance Curves
10 Fitting Performance Curves
Angilletta 2006 11 Rule-based modeling
organism environment remains is habitable
organism ‘analyzes’ environment
environment organism is not expires habitable
12 13 Biosignatures
• Note: degeneracies may exist between biotic/abiotic processes which may convolute spectral signatures.
14 Next Steps: Model Validation
1. Astroecology model vetting: validate model under observed Earth environmental temperatures 2. Constraining Earth-like exoplanets: execute Earth model with variable parameters (e.g. eccentricity, obliquity, star-planet separation, stellar age) to identify limits in parameter space 3. Identifying habitable exoplanets: execute model for confirmed rocky exoplanets
15 Acknowledgements Planetary Research Laboratory
[email protected] @thealmashow 16