An Informational-Entropic Approach to Exoplanet Characterization

In the past, measures of “Earth-likeness” of exoplanets have been qualitative, considered an abiotic Earth, or required discretionary choices of what parameters make a planet Earth-like.

With the advent of high-resolution exoplanet spectroscopy, there is a growing need for a method of quantifying the Earth-likeness of a planet that addresses these issues while making use of the data available from modern telescope missions.

In this work, we introduce an informational-entropic metric that makes use of the spectrum of an exoplanet to directly quantify how Earth-like the planet is. To illustrate our method, we generate simulated transmission spectra of a series of Earth-like and super-Earth exoplanets, as well as an exoJupiter and several gas giant exoplanets.

As a proof of concept, we demonstrate the ability of the information metric to evaluate how similar a planet is to Earth, making it a powerful tool in the search for a candidate Earth 2.0.

Sara Vannah, Ian D. Stiehl, Marcelo Gleiser

Comments: 21 pages, 5 figures. Accepted at Entropy
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2206.13344 [astro-ph.EP] (or arXiv:2206.13344v2 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2206.13344
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Related DOI:
https://doi.org/10.3390/e27040385
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Submission history
From: Sara Vannah
[v1] Mon, 27 Jun 2022 14:46:52 UTC (230 KB)
[v2] Fri, 11 Apr 2025 22:42:59 UTC (1,726 KB)
https://arxiv.org/abs/2206.13344
Astrobiology