Understanding the long-term evolution of Venus has become increasingly important as scientists study rocky exoplanets and attempt to distinguish Earth-like worlds from hostile environments. A recent study led by Rodolfo Garcia at the University of Washington used advanced simulations to explore how Venus developed over 4.5 billion years, aiming to explain why it diverged so dramatically from Earth despite their similarities in size and composition.
The researchers used an open-source modeling tool called VPLanet to simulate planetary evolution under a wide range of conditions. They ran 234,000 simulations, each assuming that Venus has always operated under a “stagnant lid” tectonic regime—meaning its crust does not break into moving plates like Earth’s. This assumption is critical because plate tectonics on Earth helps regulate temperature and recycle carbon, processes that are largely absent on Venus.
To ensure realism, the simulations were constrained to match present-day observations of the planet: an atmosphere dominated by carbon dioxide at about 92 bars, extremely low water content, and a very weak or nonexistent magnetic field. Surprisingly, only 0.35% of the simulations successfully reproduced these conditions, highlighting how specific and rare the evolutionary path of the planet may be.
Among the successful outcomes, scientists identified four main evolutionary pathways. The most common scenario, accounting for 72% of successful cases, involved gradual cooling of the mantle and core over time. Another pathway, seen in 18% of cases, described a “magnetically dying” planet where internal water loss led to stiffening of the mantle and reduced heat flow. A third scenario involved a poorly developed inner core, limiting the generation of a magnetic field. The final, rare scenario showed extreme early fluctuations in internal temperature before stabilizing.
The study also identified key factors influencing planetary evolution, including initial water content in the mantle, mantle viscosity, volcanic activity, and the melting point of the core. These variables strongly determined whether a simulation could replicate the harsh surface conditions observed today.
One of the most intriguing findings is that, despite its dry and hostile surface, the planet may still contain significant amounts of water deep within its interior—potentially as much as Earth’s oceans. This suggests that its transformation into a hot, arid world may not have involved complete water loss, but rather redistribution and trapping beneath the surface.
The simulations also predict that the planet may still be geologically active, though less intensely than previously thought. Additionally, in 88% of successful models, the planet once had a magnetic field early in its history. If true, remnants of this ancient magnetic field could still be preserved in surface rocks, offering a potential target for future exploration.
Upcoming missions—including NASA’s DAVINCI and VERITAS, and ESA’s EnVision—aim to test these predictions by analyzing the atmosphere, mapping the surface, and probing beneath the thick cloud cover. These missions could provide critical insights into how Venus evolved and why it became so different from Earth, ultimately helping scientists better understand the potential habitability of planets beyond our solar system.