Habitable Zone Predictions And How To Test Them


Various representations of the CO2-H2O HZ. The classical CO2 HZ boundaries (blue), extended for A- M stars (2,600 – 10,000 K)[13] shown alongside the extensions provided by the CO2-H2 (red)[12]and CO2-CH4 (green)[13] alternative HZ definitions. Some exoplanets and solar system planets are also shown.

The habitable zone (HZ) is the region around a star(s) where standing bodies of water could exist on the surface of a rocky planet.

The classical HZ definition makes a number of assumptions common to the Earth, including assuming that the most important greenhouse gases for habitable planets are CO2 and H2O, habitable planets orbit main-sequence stars, and that the carbonate-silicate cycle is a universal process on potentially habitable planets.

Here, we discuss these and other predictions for the habitable zone and the observations that are needed to test them. We also, for the first time, argue why A-stars may be interesting HZ prospects. Instead of relying on unverified extrapolations from our Earth, we argue that future habitability studies require first principles approaches where temporal, spatial, physical, chemical, and biological systems are dynamically coupled.

We also suggest that next-generation missions are only the beginning of a much more data-filled era in the not-too-distant future, when possibly hundreds to thousands of HZ planets will yield the statistical data we need to go beyond just finding habitable zone planets to actually determining which ones are most likely to exhibit life.
Comments: White paper submitted to the NAS Astro 2020 decadal survey(5 pages, 1 figure + cover page, 13 co-authors + 9 co-signers). Link: this http URL

Dorian S. Abbot, Yuka Fujii, Keiko Hamano, Edwin Kite, Amit Levi, Manasvi Lingam, Theresa Lueftinger, Tyler D. Robinson, Andrew Rushby, Laura Schaefer, Elizabeth Tasker, Giovanni Vladilo, Robin D. Wordsworth
(Submitted on 9 Mar 2019)

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1903.03706 [astro-ph.EP] (or arXiv:1903.03706v1 [astro-ph.EP] for this version)
Submission history
From: Ramses Ramirez
[v1] Sat, 9 Mar 2019 00:35:01 UTC (251 KB)
https://arxiv.org/abs/1903.03706
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