Considerations for the habitable zone of super-Earth planets in Gliese 581

TL;DR

This paper evaluates the potential habitability of planets Gliese 581 c and d by analyzing climate, atmospheric, and rotational factors, suggesting both could support life under certain conditions.

Contribution

It introduces new assessments of habitability for Gliese 581 c and d considering gravitational locking and atmospheric greenhouse effects.

Findings

Planet d could be habitable with a 100K greenhouse effect.

Planet c might sustain surface water through atmospheric circulation.

Both planets could develop habitable conditions under specific scenarios.

Abstract

We assess the possibility that planets Gliese 581 c and d are within the habitable zone. In analogy with our solar system, we use an empirical definition of the habitable zone. We include assumptions such as planetary climates, and atmospheric circulation on gravitationally locked synchronous rotation. Based on the different scenarios, we argue that both planets in Gliese 581 could develop conditions for a habitable zone. In an Earth-like environment planet d could be within a habitable zone, if an atmosphere producing greenhouse effect of 100K could have developed. If the planets are gravitationally locked-in, planet c could develop atmospheric circulation that would allow it to reach temperatures consistent with the existence of surface liquid water, which in turn could support life.