A team of geophysicists from UC San Diego’s Scripps Institution of Oceanography has proposed a new explanation for the unusual crown-like features covering the surface of Venus—the hottest planet in our solar system.
These circular structures, called coronae, vary dramatically in size. Some appear as raised plateaus, while others resemble sunken depressions. Until now, the mechanisms driving their formation have remained poorly understood. In a study published in Proceedings of the National Academy of Sciences, the researchers present a model that accounts for the origin and diversity of these landforms.
“There’s a clear pattern on Venus that holds important clues,” said lead author Madeleine Kerr, a PhD student at Scripps Oceanography. “We believe our findings provide the key to deciphering how these coronae came to be.”
Supported by NASA and the Department of Energy, the research enhances our understanding of Earth’s so-called twin. Venus is similar in size to our planet and orbits nearby, yet its thick, greenhouse-gas-rich atmosphere produces extreme surface temperatures—even higher than those on Mercury, which is closer to the Sun.
According to Kerr, studying Venus offers a unique opportunity to learn why life emerged on Earth but not on our nearest planetary neighbor.
“We have a solar system-scale laboratory right next door,” she said. “It’s a front-row seat to understanding planetary evolution.”
The team modeled how plumes of magma rise from Venus’s core—nearly 3,000 kilometers deep—through a single rigid crust, unlike Earth’s fragmented tectonic plates. While the largest plumes can produce massive volcanic structures over 1,200 miles wide, many are weaker and cannot penetrate the upper mantle.
At around 600 kilometers deep, these weaker upwellings encounter a barrier formed by changes in rock crystal structure—a “glass-ceiling” effect that blocks further ascent. Some material accumulates at this boundary, while smaller, secondary plumes break through to form the numerous, smaller coronae observed across the planet.
David Stegman, a Scripps geophysicist and Kerr’s advisor, compared the current understanding of Venus to geoscientists’ knowledge of Earth before the widespread acceptance of plate tectonic theory half a century ago.
“Right now, Venus is where Earth science was in the 1960s—we’re still searching for a unifying theory that links interior heat flow to surface features,” Stegman said. “With this new model, we believe we are on the verge of a revolution. Many more exciting discoveries await.”
Co-authors of the study include Suzanne Smrekar of NASA’s Jet Propulsion Laboratory and Andrea Adams of Scripps and JPL.
