Implications of tides for life on exoplanets

TL;DR

This paper explores how strong tidal forces on Earth-sized exoplanets in low-mass star systems could significantly influence biological processes and produce detectable biosignatures like large-scale algal blooms.

Contribution

It identifies conditions where tides could positively impact biotic processes and suggests large-scale algal blooms as potential biosignatures caused by tidal forces.

Findings

Tides may enhance biotic processes such as nutrient upwelling and photosynthesis.

Strong tidal forces could lead to observable large-scale algal blooms.

Tidal influences might serve as indirect biosignatures in exoplanet observations.

Abstract

As evident from the nearby examples of Proxima Centauri and TRAPPIST-1, Earth-sized planets in the habitable zone of low-mass stars are common. Here, we focus on such planetary systems and argue that their (oceanic) tides could be more prominent due to stronger tidal forces. We identify the conditions under which tides may exert a significant positive influence on biotic processes including abiogenesis, biological rhythms, nutrient upwelling and stimulating photosynthesis. We conclude our analysis with the identification of large-scale algal blooms as potential temporal biosignatures in reflectance light curves that can arise indirectly as a consequence of strong tidal forces.