科研之友
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摘要
A terrestrial planet in an orbit far outside of the standard habitable zone could maintain surface liquid water as a result of H-2-H-2 collision-induced absorption by a thick H-2 atmosphere. Without a stabilizing climate feedback, however, habitability would be accidental and likely brief. In this letter I propose stabilizing climate feedbacks for such a planet that require only that biological functions have an optimal temperature and operate less efficiently at other temperatures. For example, on a planet with a net source of H-2 from its interior, H-2-consuming life (such as methanogens) could establish a stable climate. If a positive perturbation is added to the equilibrium temperature, H-2 consumption by life will increase (cooling the planet) until the equilibrium climate is reestablished. The potential existence of such feedbacks makes H-2-warmed planets more attractive astrobiological targets.
- 出版日期2015-12-10
