Transits of Earth-Like Planets
L. Kaltenegger, W.A. Traub

TL;DR
Transmission spectroscopy of Earth-like exoplanets can potentially identify biomarkers, but detecting these features requires multiple transits due to low signal-to-noise ratios, especially around Sun-like stars.
Contribution
This study quantifies the detectability of atmospheric biomarkers on Earth-like exoplanets using transmission spectroscopy, highlighting the challenges and necessary observational strategies.
Findings
Signal-to-noise ratios are generally below 1 per transit for key spectral features.
Clouds do not significantly hinder biomarker detection due to aerosol and Rayleigh scattering.
Multiple transits are needed to reliably detect atmospheric features in Earth-like exoplanets.
Abstract
Transmission spectroscopy of Earth-like exoplanets is a potential tool for habitability screening. Transiting planets are present-day "Rosetta Stones" for understanding extrasolar planets because they offer the possibility to characterize giant planet atmospheres and should provide an access to biomarkers in the atmospheres of Earth-like exoplanets, once they are detected. Using the Earth itself as a proxy we show the potential and limits of the transiting technique to detect biomarkers on an Earth-analog exoplanet in transit. We quantify the Earths cross section as a function of wavelength, and show the effect of each atmospheric species, aerosol, and Rayleigh scattering. Clouds do not significantly affect this picture because the opacity of the lower atmosphere from aerosol and Rayleigh losses dominates over cloud losses. We calculate the optimum signal-to-noise ratio for spectral…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
