English

Relative Likelihood for Life as a Function of Cosmic Time

Cosmology and Nongalactic Astrophysics 2016-08-31 v2 Earth and Planetary Astrophysics Solar and Stellar Astrophysics High Energy Physics - Theory

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.

Keywords

Cite

@article{arxiv.1606.08448,
  title  = {Relative Likelihood for Life as a Function of Cosmic Time},
  author = {Abraham Loeb and Rafael A. Batista and David Sloan},
  journal= {arXiv preprint arXiv:1606.08448},
  year   = {2016}
}

Comments

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

R2 v1 2026-06-22T14:35:42.898Z