NASA simulations suggest early Venus may have been habitable

NASA climate simulations suggest that early Venus may have been habitable for nearly three billion years, featuring surface liquid water and moderate temperatures between 20 and 50°C. Using the ROCKE-3D general circulation model, researchers Michael Way and Anthony Del Genio conducted 45 experiments to simulate various stages of Venusian history, including variations in atmospheric composition, topography, and rotation.

The simulations indicate that if Venus’s primordial magma ocean cooled quickly, steam could have condensed into rain and formed oceans. This temperate phase may have lasted until massive volcanic outgassing approximately 700 million years ago transformed the planet into its current high-pressure, high-temperature state.

However, the possibility of an ocean-bearing Venus remains a subject of scientific debate. Competing models from researchers at the University of Geneva suggest that runaway greenhouse effects may have prevented water vapor from ever condensing, leaving water permanently suspended as a gas and precluding the formation of oceans.