The surface of Venus is marked by strange, circular features called coronae. These can be huge, stretching hundreds of miles, or smaller, only a few dozen miles across. From space, they look like chaotic patterns on the rock, with a partially collapsed center at their heart.
The origin of these coronae has puzzled scientists for years. Venus is often called Earth’s “twin” because it’s similar in size and density. Both planets are neighbors in the solar system, so why does Venus have all these structures while Earth does not?
A recent study in the Proceedings of the National Academy of Sciences offers an intriguing answer and sheds light on how the two planets have evolved so differently. Venus is an incredibly hot world, with surface temperatures soaring above 860 degrees Fahrenheit, while Earth is a cooler, life-filled water planet.
Madeleine Kerr, the lead author from UC San Diego’s Scripps Institution of Oceanography, explains, “We have a solar system-sized laboratory. We can see why these planets are so different.”
One of the key differences is in their surfaces. Venus has a solid crust, while Earth is made up of moving tectonic plates. This movement allows Earth’s crust to recycle itself, but Venus seems to have stayed in a more primitive state. Scientists believe that Venus once had tectonic plates, too, but they don’t know when this change occurred.
Interestingly, research from NASA’s Magellan mission suggested that Venus might not be as geologically inactive as previously thought. The coronae might actually be signs of ongoing geological activity.
One theory of how coronae form is that they start when hot material from the mantle of Venus pushes upward, causing the crust to bulge. The recent study built on this idea by examining how this hot material might move from deep within the planet.
Researchers discovered that the mantle has a “glass ceiling”—a layer about 400 miles beneath the surface that blocks some of the rising hot material. Instead of one large mass, smaller blobs of hot material reach the surface. This might explain why coronae come in such different sizes.
While more research is needed, the findings hint at a breakthrough comparable to the discovery of plate tectonics on Earth. As coauthor David Stegman puts it, “We feel a revolution has begun.”
Keeping an eye on this research could reveal even more surprises about Venus and our understanding of planetary geology.
For more on planetary science, check out this article from NASA about Venus’ tectonic activity.
