Tidal Heating of Terrestrial Extra-Solar Planets and Implications for their Habitability

TL;DR

This paper models tidal heating in terrestrial exoplanets to understand its effects on habitability, revealing conditions under which planets may sustain life-friendly environments or become volcanically extreme.

Contribution

It provides a detailed model of tidal heating effects on exoplanets, linking orbital and physical properties to potential habitability outcomes.

Findings

Tidal heating can drive plate tectonics, enhancing habitability.

Excessive tidal heating may cause extreme volcanism, reducing habitability.

Tidal heating can generate subsurface oceans, supporting life prospects.

Abstract

The tidal heating of hypothetical rocky (or terrestrial) extra-solar planets spans a wide range of values depending on stellar masses and initial orbits. Tidal heating may be sufficiently large (in many cases, in excess of radiogenic heating) and long-lived to drive plate tectonics, similar to the Earth's, which may enhance the planet's habitability. In other cases, excessive tidal heating may result in Io-like planets with violent volcanism, probably rendering them unsuitable for life. On water-rich planets, tidal heating may generate sub-surface oceans analogous to Europa's with similar prospects for habitability. Tidal heating may enhance the outgassing of volatiles, contributing to the formation and replenishment of a planet's atmosphere. To address these issues, we model the tidal heating and evolution of hypothetical extra-solar terrestrial planets. The results presented here constrain the orbital and physical properties required for planets to be habitable.