On the Habitability of Our Universe

TL;DR

This paper examines the cosmic timeline of habitability, suggesting that life could be most common around low-mass stars in the distant future, based on cosmological models and planet formation history.

Contribution

It provides a comprehensive analysis of the universe's habitability over cosmic history, emphasizing the potential prevalence of life around low-mass stars in the far future.

Findings

Habitability began ~30 million years after the Big Bang.

Life may be most likely around 0.1 solar mass stars in 10 trillion years.

Spectroscopic searches can test the prevalence of life around low-mass stars.

Abstract

Is life most likely to emerge at the present cosmic time near a star like the Sun? We consider the habitability of the Universe throughout cosmic history, and conservatively restrict our attention to the context of "life as we know it" and the standard cosmological model, LCDM. The habitable cosmic epoch started shortly after the first stars formed, about 30 Myr after the Big Bang, and will end about 10 Tyr from now, when all stars will die. We review the formation history of habitable planets and find that unless habitability around low mass stars is suppressed, life is most likely to exist near 0.1 solar mass stars ten trillion years from now. Spectroscopic searches for biosignatures in the atmospheres of transiting Earth-mass planets around low mass stars will determine whether present-day life is indeed premature or typical from a cosmic perspective.