A Catalog of Rocky Exoplanets in the Habitable Zone and Their Light Fingerprints
Gillis Lowry
Department of Physics & Astronomy
Faculty Supervisor: Eileen Gonzales
Most of the 6000 discovered planets orbiting other stars are deadly, but a small fraction are rocky, Earth-like worlds that orbit in their star’s “habitable zone” (HZ): the theorized range of distances from a star where temperatures may be right for liquid water on a planet’s surface. With limited telescope time and ever-growing numbers of exoplanets, observers need constantly-updated catalogs to determine the most Earth-like and most easily observable candidates in the search for life.
My research provides differing estimates from previous catalogs by considering up-to-date data from multiple sources. I also implement metrics to rank the observability of each planet. Future observations can help determine if these planets have an atmosphere, and whether that atmosphere holds signs of life; my work further examines the James Webb Space Telescope’s (JWST) ability to detect Earth-like atmospheres on 10 of the most Earth-like planets. I produced atmospheric models for each planet based on modern Earth and Earth 0.8, 2.0, and 3.9 billion years ago, representing a range of possibly habitable atmospheres. This analysis shows that JWST can only detect atmospheres for two of the 10 planets, with specific molecules (methane and carbon dioxide) only possible to detect for one planet.
My rocky HZ planet catalog and atmospheric models provide reference points in the search for life with JWST, but also underscore the necessity of funding more powerful telescopes. With such future telescopes and catalogs to guide us, the discovery of life may be less than decades away.