Relative Likelihood for Life as a Function of Cosmic Time

Abstract

Is life most likely to emerge at the present cosmic time near a star like the Sun? We address this question by calculating the relative formation probability per unit time of habitable Earth-like planets within a fixed comoving volume of the Universe, dP(t)/dt, starting from the first stars and continuing to the distant cosmic future. We conservatively restrict our attention to the context of "life as we know it" and the standard cosmological model, LCDM. We 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.

10 pages, 4 figures, accepted for publication in the Journal of Cosmology and Astroparticle Physics (JCAP)

References in corpus (8)

• Cosmic Star Formation History
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• Reduced Diversity of Life Around Proxima Centauri and TRAPPIST-1
• The Impact of the Temporal Distribution of Communicating Civilizations on their Detectability
• A Bayesian Analysis of Technological Intelligence in Land and Oceans
• Is there another coincidence problem at the reionization epoch?
• The Drake Equation as a Function of Spectral Type and Time
• Beyond Mediocrity: How Common is Life?