Venus may be volcanically alive right now — but from Earth, scientists have no way to confirm it. The clues needed to answer that question may have arrived from an unlikely source: a 13-day eruption on a Hawaiian island in late 2022.
When Mauna Loa roared back to life that November, lava crept to within two miles of a major island highway while satellites tracked every movement from orbit. The data those satellites captured turned out to be far more than a local emergency record.
Venus: a volcanic world frozen in question
Venus is covered in volcanoes — more than 85,000 have been identified across its surface through radar imaging. For decades, the prevailing view held that this volcanic activity occurred in a single massive episode roughly 500 million years ago, resurfacing most of the planet before going quiet. That picture has been shifting.
A fresh analysis of radar data collected by NASA’s Magellan spacecraft during the 1990s has turned up what appears to be evidence of volcanism happening today. Atmospheric measurements add to the case: scientists have detected anomalies in carbon dioxide, sulfur dioxide, and molecular nitrogen levels consistent with active volcanic outgassing. Anomalies, though, aren’t proof. No volcanic plumes have been directly observed, and whether Venus is currently volcanically active remains formally unanswered.
A Hawaiian eruption watched from orbit
When Mauna Loa erupted in November 2022, it drew immediate attention. The eruption lasted 13 days, and lava flows advanced to within 1.7 miles of the Daniel K. Inouye State Highway 200 — known locally as Saddle Road — a major artery on the Big Island. The threat to infrastructure made close monitoring a priority.
Government-operated monitoring satellites are limited in number, so geologist Ian Flynn of the University of Pittsburgh turned to a different resource. Working with data from privately owned satellites, which have been launching in growing numbers, Flynn combined public and private feeds to track the lava flow in near real-time. Private satellite data filled gaps that government assets alone couldn’t cover, delivering a more complete picture of how the flow behaved hour by hour — and that combination proved unexpectedly rich.
Machine learning detects heat a month before eruption
With a detailed satellite record in hand, Flynn and his colleagues began looking backward through the data, examining what the instruments had captured before the eruption began. Working with Claudia Corradino of the Italian National Institute of Geophysics and Volcanology, the team applied machine learning techniques to the pre-eruption archive.
The analysis revealed a detectable buildup of underground heat approximately one month before Mauna Loa’s eruption started. Predicting when a volcano will erupt has long been described as the holy grail of volcanology. This particular finding is retrospective — drawn from data already collected — but it demonstrates that the precursor signal was present in the satellite record and that machine learning can surface it. A meaningful step toward understanding what to look for before an eruption begins.
From flat images to 3D lava thickness
Standard satellite observation has a fundamental limitation: it produces flat, two-dimensional images. Lava flow thickness — a critical variable in how long it moves and how quickly it cools — is essentially invisible from orbit under conventional methods.
Flynn addressed this by collaborating with Shashank Bhushan at NASA’s Goddard Space Flight Center. Bhushan had previously developed techniques to measure the thickness of flowing glaciers using satellite data, and the team adapted that methodology to lava, successfully reconstructing three-dimensional flow thickness from orbital imagery of the Mauna Loa eruption. The results added an entirely new layer of information to what the satellites had already captured. “Getting visible data helped us understand where it’s going,” Flynn said. “Now we can also generate flow thickness and understand how much material is coming out.” One concrete finding from the 3D data: lava flows thicker than 20 meters — roughly 66 feet — took approximately 21 months to cool completely.
What this means for Venus — and missions ahead
That cooling timeline carries implications well beyond Hawaii. The rate at which lava cools can indicate whether an eruption is in its early, vigorous phase or winding down, and it can also provide information about the lava’s elemental and mineral composition. Together, those details form a kind of thermal fingerprint.
The same logic applies off-world. If scientists detect a thermally active lava flow on Venus, Earth-derived cooling models could help interpret what stage that eruption is in and what the lava is made of. “Knowing how lava cools enables scientists to better constrain our models when we find active volcanoes on other planets,” Flynn said.
This research aligns with growing momentum in Venus exploration. NASA’s VERITAS mission — Venus Emissivity, Radio Science, InSAR, Topography and Spectroscopy — is targeted for launch in the early 2030s and could plausibly detect recent lava flows on the planet’s surface. When it does, scientists will need tools to interpret what they’re seeing. The Mauna Loa dataset, and the methods built from it, could provide exactly that foundation.
The findings are scheduled for publication in the June 2026 issue of the Journal of Volcanology and Geothermal Research — arriving just in time to inform the next generation of planetary missions before they leave the ground.