Venus and Earth are geological twins that took radically different paths
For generations, Earth stood alone among its neighbors as a world still burning from within — but archived radar images and fresh geological surveys now suggest that Venus and Mars may share that restless inner fire. A volcanic vent on Venus quietly doubled in size across eight months in 1991, while Mars bears the scars of eruptions as recent as 50,000 years ago, a mere heartbeat in planetary time. These discoveries invite us to reconsider what it means for a world to be 'alive,' and whether the conditions that stir geology might also, somewhere beneath the ice and ash, stir life itself.
- Decades of certainty that Earth alone harbored active volcanoes are crumbling under the weight of newly analyzed archival data from two neighboring planets.
- A vent near Venus's Maat Mons nearly doubled in size between February and October of 1991 — a transformation so dramatic it may represent a lava lake forming in near-real time.
- Mars complicates the picture further: fresh ash deposits near Cerberus Fossae and ongoing seismic tremors detected by NASA's InSight lander suggest the planet's interior has not gone quiet.
- Scientists are racing to reinterpret earlier mysteries — including the detection of phosphine in Venus's atmosphere — through the new lens of possible ongoing volcanism.
- The prospect that volcanic heat beneath Martian ice could create habitable pockets for microbial life has shifted from idle speculation to a question worth taking seriously.
For decades, Earth's volcanoes seemed like the solar system's only active geological furnaces. That assumption is now giving way. New analysis of old data suggests both Venus and Mars likely harbor volcanoes still erupting today — and the implications reach far beyond geology.
The Venus evidence comes from radar images captured by NASA's Magellan spacecraft in the early 1990s. Geophysicist Robert Herrick of the University of Alaska Fairbanks spent years combing through these archives, searching for signs of change near sites already suspected of volcanic activity. Near Maat Mons, a vast shield volcano, he found them. A vent on the volcano's northern flank transformed dramatically between February and October of 1991 — nearly doubling in size from roughly 2.2 to 4 square kilometers and shifting from a near-circular opening to an irregular, brimming shape that may have become a lava lake. The change is unmistakable, even if questions about the material's state remain open.
The finding carries particular weight because Venus and Earth are geological twins in many respects — similar in size, mass, and composition — yet they have evolved along radically different paths. Unlike Earth, Venus lacks tectonic plates, making its continued volcanic activity harder to explain and all the more significant to confirm. The discovery also reframes earlier puzzles: phosphine gas detected in Venus's atmosphere, once speculatively linked to life, may find a more straightforward explanation in volcanic chemistry.
Mars tells a parallel story. Scientist David Horvath has identified fresh deposits of ash and burned rock near the Cerberus Fossae region, pointing to eruptions as recent as 50,000 years ago — a geological instant. Seismic tremors detected by NASA's InSight mission trace back to that same region, suggesting Mars's interior remains restless. More provocatively, if magma still rises beneath the planet's frozen surface, the heat it generates could create conditions hospitable to microbial life — perhaps even now. Both worlds, it turns out, may be far more alive than we had allowed ourselves to imagine.
For decades, Earth's volcanoes seemed like the only active geological furnaces in our solar system. But new analysis of old data has upended that assumption, revealing that both Venus and Mars likely harbor volcanoes that are still erupting today—reshaping not just the surfaces of these distant worlds, but our understanding of how planets evolve.
The evidence comes from an unexpected place: radar images captured by NASA's Magellan spacecraft in the early 1990s, orbiting Venus. Geophysicist Robert Herrick at the University of Alaska Fairbanks spent years combing through these archived images, which only recently became available in high resolution and easy to manipulate on a standard computer. He focused on sites already suspected of volcanic activity, examining them methodically for any signs of change. What he found near two of Venus's largest volcanoes—Ozza and Maat Mons—was striking. A vent on the northern flank of Maat Mons, a shield volcano comparable in volume to Earth's largest volcanoes but far flatter and more spread out, had transformed dramatically. Between February and October of 1991, the vent nearly doubled in size. It began as an almost circular opening covering roughly 2.2 square kilometers—slightly larger than Monaco. Eight months later, it had swollen to about 4 square kilometers and taken on an irregular shape, appearing nearly filled to the brim, possibly becoming a lava lake. Whether the material inside remained molten at the time of the second image remains unclear, but the change itself is unmistakable.
Scott Hensley, an engineer at NASA's Jet Propulsion Laboratory, emphasized the significance: this represents ongoing volcanic activity reshaping Venus's surface. The finding carries weight because Venus and Earth are geological twins in many ways—similar in size, mass, density, and composition. Yet they have taken radically different paths. Earth is wet, temperate, and teeming with life. Venus is bone-dry, hellishly hot, and wrapped in a toxic, suffocating, turbulent atmosphere. One key difference lies in their outer rocky layers. Earth's lithosphere is like a cracked eggshell, broken into multiple pieces—tectonic plates whose edges grind against each other. Most of Earth's volcanic activity occurs along these boundaries. Venus's lithosphere, by contrast, is a complete, unbroken shell with no tectonic plates. This has long puzzled scientists: how can Venus be volcanically active without the plate boundaries that drive most volcanism on Earth? The planet's young surface suggests recent volcanic upheaval, but whether it remains active, and to what degree, has remained an open question—until now.
The discovery has implications beyond Venus itself. Phosphine gas detected in Venus's atmosphere was initially attributed to possible life, but volcanic activity could explain it just as well. Understanding Venus's current geological state becomes crucial for interpreting such observations. Yet studying Venus remains extraordinarily difficult. Its thick carbon dioxide atmosphere blocks direct views of the surface, requiring specialized imaging techniques that can penetrate the haze. Few spacecraft have visited Venus, and fewer still have been designed to monitor its surface over time. Japan's Akatsuki probe, operated by the Aerospace Exploration Agency, is currently the only spacecraft there, but it studies the atmosphere, not the ground. Other probes have flown past and taken snapshots, but sustained observation—the kind needed to track volcanic changes—remains elusive.
Mars tells a different but equally compelling story. Scientist David Horvath at the Planetary Science Institute in Arizona has identified fresh deposits of what appear to be ash and burned rock near the Cerberus Fossae region, suggesting volcanic eruptions far more recent than previously thought. The most recent of these catastrophic outbursts may have occurred only 50,000 years ago—a blink of an eye in geological time. This challenges the long-held assumption that Martian volcanism was ancient history. Intriguingly, recent seismic tremors detected by NASA's InSight mission have their origins in the same Cerberus Fossae region, hinting that the planet's interior remains restless.
The implications extend beyond geology. If magma is still rising beneath Mars's frozen surface, the interaction between hot lava and ice could create conditions favorable for microbial life—recently, or even now. Horvath himself acknowledges this ventures into speculation, but the possibility is real enough to matter. As NASA rovers and landers continue exploring Mars, they may yet stumble upon evidence of life in regions where volcanic heat still warms the ground. Both Venus and Mars, it seems, are far more alive than we assumed.
Notable Quotes
Venus and Earth have much in common in size, mass, density, and composition, but for two similar pieces of rock, they surely took different paths— Scott Hensley, NASA Jet Propulsion Laboratory
The recent age of this deposit raises the absolute possibility that there could still be volcanic activity on Mars, and it is intriguing that recent seismic events detected by InSight originate in Cerberus Fossae— David Horvath, Planetary Science Institute
The Hearth Conversation Another angle on the story
Why did it take so long to notice that Venus's volcano had changed? The images existed for thirty years.
The data was there, but not in a form anyone could easily work with. It took modern computing power and someone patient enough to look. Herrick had to manually examine images, comparing them side by side across eight months. That's tedious work, but it's how you catch what changed.
So we're looking at a vent that nearly doubled in size. What does that actually mean—is the volcano erupting right now?
We don't know if it's erupting now. We know it erupted between those two radar passes in 1991. The vent filled with material, possibly lava. But Venus is so hard to observe that we can't track it continuously. We're working with snapshots.
Why does it matter if Venus has active volcanoes? It's already a hellscape.
Because it changes how we interpret everything we observe there. If phosphine gas is detected in the atmosphere, is it a sign of life, or just volcanic outgassing? If the surface is young and still being reshaped by eruptions, that tells us the planet is geologically dynamic in ways we didn't fully appreciate. It's about understanding what's actually happening.
And Mars—the ash deposits are only 50,000 years old. That's recent.
Extremely recent. For context, humans were already painting caves and migrating across continents. On Mars, that's when volcanoes were still active. The seismic data from InSight picking up tremors in the same region suggests the interior is still warm, still moving.
Could there be life in those volcanic zones?
Possibly. Where magma meets ice, you get heat, water, and chemical energy—the ingredients life needs. It's speculative, but it's not absurd. And if there is life, our rovers might find it.
So we've been looking at dead planets this whole time, and they're not dead at all.
Not dead. Just harder to read than we thought.