The Habitable Zone: Boundaries, Temporal Shifts, and Exoplanet Habitability

To the point

The habitable zone is the region around a star where a rocky planet could keep liquid water on its surface, determined by the star’s brightness, greenhouse gases, a planet’s reflectivity, and heat transport, with inner and outer edges set by runaway warming and the limit of warmth, currently about 0.9 to 1.5 AU for Sun‑like stars and moving outward as the star brightens, which means Venus could have been warmer in the past and Mars may warm in the future, while moons like Europa could harbor subsurface oceans, and Earth‑sized worlds such as Proxima Centauri b, some TRAPPIST‑1 planets, and Kepler‑452b are studied as potential members.