Earth is accompanied by a large, bright Moon that has played a significant role in stabilizing its axial tilt and influencing tides. In stark contrast, Venus, often called Earth’s sister planet due to similar size and composition, possesses no natural satellite. This absence raises the question of whether Venus ever had a moon and, if so, what happened to it.
Scientists have long considered the possibility that Venus may have acquired a moon early in the Solar System’s history, perhaps through a giant impact similar to the event that formed Earth’s Moon. Such a satellite would have orbited the planet during its formative years, but direct evidence remains lacking.
Recent research addresses this question by modelling the long‑term stability of a hypothetical Venus moon. The results indicate that any moon formed around Venus would have been unable to maintain a stable orbit for an extended period. Gravitational perturbations, especially from the Sun’s strong tidal influence, would have gradually altered its path, leading to escape or collision with the planet.
These findings suggest that the lack of a present‑day moon on Venus is not merely a coincidence but a likely outcome of dynamical processes that prevented long‑term retention. Understanding why some rocky planets keep their moons while others do not helps refine models of planet formation and satellite evolution across the Solar System.