Is Venus alive? New signs of volcanic activity emerge

Using radar data from a NASA mission launched more than three decades ago, scientists have found fresh clues suggesting that Venus may still be geologically active.

Strange, circular structures across the planet’s surface might not just be leftover scars of ancient events – they could point to ongoing tectonic activity that is reshaping Venus even now.

These features, called coronae, caught the attention of researchers at the University of Maryland and NASA’s Goddard Space Flight Center.

The findings are based on data collected by NASA’s Magellan mission, which orbited Venus in the 1990s. Magellan’s radar system penetrated the thick clouds cloaking the planet, revealing its topography in detail that still hasn’t been surpassed.

Activity beneath the surface of Venus

Coronae are large, oval-shaped formations that can span from a few dozen to hundreds of miles. They’re surrounded by rings of fractures and thought to be shaped by rising plumes of molten rock from beneath Venus’ surface.

These plumes push against the planet’s crust and upper mantle – collectively called the lithosphere – creating the distinctive ring-like patterns.

“Coronae are not found on Earth today; however, they may have existed when our planet was young and before plate tectonics had been established,” noted Gael Cascioli, a research scientist at NASA Goddard.

“By combining gravity and topography data, this research has provided a new and important insight into the possible subsurface processes currently shaping the surface of Venus.”

The researchers studied 75 coronae. Of those, 52 showed signs of hot, buoyant mantle material underneath – suggesting that Venus’ surface isn’t as quiet as we once believed.

Magellan’s lasting impact

NASA’s Magellan spacecraft, managed by the Jet Propulsion Laboratory in California, launched in 1989 and gathered the most detailed gravity and topographic data of Venus available.

Back then, scientists weren’t sure what to make of coronae. They didn’t know how they formed, or what role – if any – they played in the planet’s geologic activity.

Over time, more coronae were found in areas where Venus’ lithosphere appeared thinner and hotter, hinting at a connection between heat flow and corona formation.

“Coronae are abundant on Venus. They are very large features, and people have proposed different theories over the years as to how they formed,” said Anna Gülcher, a planetary scientist at the University of Bern.

“The most exciting thing for our study is that we can now say there are most likely various and ongoing active processes driving their formation. We believe these same processes may have occurred early in Earth’s history.”

Gravity maps reveal tectonic activity

To better understand what’s happening beneath the surface, the research team used 3D geodynamic models and compared them with Magellan’s gravity and topography data.

The gravity maps were especially important. They helped reveal areas of less dense, rising material beneath the coronae. These would be invisible through topography alone.

The presence of plumes points to multiple tectonic mechanisms at work. One of these is subduction, where material is forced back into the planet’s interior.

Volcanic activity on Venus

On Earth, subduction involves tectonic plates sliding beneath one another. On Venus, it appears to be happening in a different way – around the edges of some coronae. There, plumes push the surface upward, and the surrounding material gets pushed back down.

Another possibility is lithospheric dripping. This is when cooler, heavier chunks of lithosphere sink into the hotter mantle below.

A third process might also be involved. Plumes under thick lithosphere sections may trigger volcanic activity at Venus’ surface.

A snapshot of Earth’s past

The idea that these processes might mirror those that occurred on early Earth is especially intriguing. Venus doesn’t have plate tectonics like we do today, but it may be offering us a snapshot of our own planet’s distant past.

Recent radar images from Magellan have already shown direct evidence of volcanic eruptions, including massive lava flows from places like Maat Mons and Sif Mons.

While these images show volcanic action, researchers still need sharper resolution to fully understand the underlying tectonics shaping the coronae.

Suzanne Smrekar is a planetary scientist at JPL and principal investigator for the VERITAS mission.

“The VERITAS gravity maps of Venus will boost the resolution by at least a factor of two to four, depending on location – a level of detail that could revolutionize our understanding of Venus’ geology and implications for early Earth,” said Smrekar.

Upcoming Venus mission

NASA’s upcoming VERITAS mission (Venus Emissivity, Radio science, InSAR, Topography, and Spectroscopy) is set to dig even deeper – figuratively speaking.

Launching no earlier than 2031, VERITAS will use synthetic aperture radar to create high-resolution 3D maps of the entire planet.

VERITAS will also use an infrared spectrometer to analyze the surface composition and a radio tracking system to measure Venus’ gravity field. Together, these tools could pinpoint areas of active surface reshaping.

As part of the VERITAS team, Cascioli and his colleagues are already preparing to use the improved data. Erwan Mazarico, also from NASA Goddard, will co-lead the mission’s gravity experiment.

The hope is that Venus can finally give up more of its secrets. And in doing so, it might tell us something about the early days of our own world.

Image Credit: Credit: NASA/JPL-Caltech/Peter Rubin

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