A catalog of 741 bizarre circular formations scarring Venus' surface holds the key to understanding why our sister planet became a hellish wasteland while Earth remained hospitable to life. Using decades-old radar data from NASA's Magellan spacecraft, planetary scientist Anna Gulcher and her colleagues at Germany's University of Freiburg have created detailed 3D models of these mysterious structures called coronae, which range from 60 kilometers to over 2,000 kilometers in diameter—and the findings suggest Venus may have once harbored geodynamic processes fundamentally different from those that saved Earth.
These concentric rings of fractures are thought to be surface expressions of plumes of hot material rising from Venus' interior, much like how a circular heat source creates ripples on a still pond. Gulcher and her team presented their groundbreaking analysis at the European Geosciences Union's 2026 General Assembly in Vienna, combining gravity measurements and topographic data with geodynamic simulations to map where these upwellings likely occur. By analyzing 52 coronae in detail, they identified possible warm mantle upwellings and uncovered evidence of diverse plume-related tectonic processes—a discovery that challenges previous assumptions that these formations represented a single, uniform mechanism.
The significance of this research extends far beyond Venus. Understanding these ancient structures is critical for determining whether processes like plate tectonics—the continuous recycling of carbon that stabilizes Earth's atmosphere—ever operated on Venus. The difference between our two planets may come down to water. On Earth, vast oceans created hydrous rocks that became pliable enough to break apart into moving tectonic plates, enabling the carbon cycle that kept our atmosphere stable across billions of years. Venus, it seems, may never have had substantial water oceans. Without them, the planet's dry rocks remained too rigid to plate, trapping carbon in its thick atmosphere and leading to a runaway greenhouse effect.
Gulcher points to a sobering reality: "They are huge circles of fracture systems that we think are basically the surface expression of a plume of hot material moving upwards from the interior of the planet." Yet this discovery carries an unexpected twist. The current gravity data used to detect these features likely misses many active tectonic signals, suggesting that Venus' geodynamic activity may be far more widespread than scientists can currently confirm. The team's work reveals gaps in our detection methods—limitations that could mask signals of ongoing planetary processes on Venus and beyond.
What makes this analysis particularly timely is that upcoming missions to Venus' surface may finally solve one of planetary science's great mysteries: whether Venus ever hosted liquid water oceans that could have altered its geological fate. If Venus once possessed the conditions for plate tectonics and was somehow robbed of them, understanding that loss could illuminate what makes Earth genuinely exceptional among rocky planets. As Gulcher's team emphasizes, plate tectonics is arguably what allowed intelligent life to evolve here—a distinction that hinges entirely on whether a young planet manages to maintain a stable carbon cycle. By decoding the coronae and the mantle convection beneath them, scientists are reading the geological record of two divergent planetary destinies.