Gases from erupting volcanoes could make planets beyond the Solar System warmer and hospitable to life, even if the planet is relatively distant from its host star.

Ramses Ramirez and Lisa Kaltenegger of Cornell University in Ithaca, New York, used a climate model to study whether hydrogen spewing from volcanoes on exoplanets could build up in their atmospheres and trap heat. Such greenhouse warming could prevent water from freezing, potentially creating favourable conditions for life.

The authors found that if an exoplanet's atmosphere contained 50% hydrogen, the planet could remain habitable 1.3 to 1.6 times farther away from its star than if it was not warmed by volcanic gas.

Astrophys. J. 837, L4 (2017)