Researchers Marrick Braam and Daniel Angerhausen, affiliated with the Center for Space and Habitability at the University of Bern, have published a study that explores the potential of future telescopes to detect variations in the atmospheres of rocky exoplanets. Their work, titled “Observing spatial and temporal variations in the atmospheric chemistry of rocky exoplanets: prospects for mid-infrared spectroscopy,” was published in the journal Astronomy & Astrophysics.
The study focuses on the capabilities of the upcoming Large Interferometer For Exoplanets (LIFE), a space-based telescope designed to characterize the atmospheres of nearby rocky exoplanets using mid-infrared spectroscopy. Braam and Angerhausen investigate how LIFE could detect spatial and temporal variations in the atmospheres of tidally locked exoplanets, which are planets that always show the same face to their host star due to gravitational interactions.
The researchers created synthetic observations of the exoplanet Proxima Centauri b, using a combination of climate-chemistry models and simulation tools to generate daily spectra. They considered two different spin-orbit resonances (SORs): a 1:1 resonance, where the planet is tidally locked, and a 3:2 resonance, where the planet rotates three times for every two orbits around its star. In the 1:1 SOR scenario, the team found that mid-infrared spectra vary significantly with the viewing geometry, indirectly probing atmospheric circulation. Nightside temperature inversions generate emission features for ozone (O3), carbon dioxide (CO2), and water vapor (H2O), although these features lie below LIFE’s detection threshold. In contrast, the 3:2 SOR yields a more homogeneous atmosphere with weaker phase variability but enhanced bolometric flux due to eccentric heating.
The study highlights the importance of phase-resolved observations, which capture the planet’s atmosphere at different points in its orbit, rather than snapshot spectra taken at arbitrary viewing geometries. Phase-resolved LIFE observations can confidently distinguish between different SORs and capture seasonal O3 variability for targets like Proxima Centauri b. However, the researchers caution that in cases of abiotic O2/O3 build-up, the O3 variability presents a potential false positive scenario for life detection.
For the energy sector, this research underscores the importance of understanding the atmospheric dynamics of exoplanets, which could harbor potential energy resources or serve as future sites for energy infrastructure. By developing advanced spectroscopic techniques and analytical tools, the energy industry can better assess the habitability and resource potential of these distant worlds. Moreover, the study’s findings could inform the design and operation of future space-based telescopes, enabling more efficient and accurate characterization of exoplanetary atmospheres.
This article is based on research available at arXiv.