Olympus Mons towers 21 kilometers above the Martian surface—that’s nearly three times the height of Everest, which makes it the solar system’s most absurdly overachieving mountain. And here’s the thing: we’re not entirely sure if it’s done erupting.
When Giant Mountains Might Actually Be Sleeping Dragons
The conventional wisdom went like this for decades: Mars is geologically dead, its volcanoes are extinct monuments, case closed. Except planetary scientists hate being comfortable with their assumptions. In 2004, the European Space Agency’s Mars Express spotted something bizarre—methane plumes in the Martian atmosphere that appeared seasonally. Methane breaks down quickly under UV radiation, so either something was actively producing it, or we’d fundamentally misunderstood Martian chemistry.
Wait—maybe the planet isn’t as dormant as we thought.
The Evidence That Keeps Scientists Awake at Night
Lava flows on Olympus Mons and other Tharsis volcanoes show remarkably few impact craters. In planetary geology, craters are like tree rings—they tell you age. Fewer craters means younger surfaces. Some of these flows might be only 2.4 million years old, which in geological terms is practically yesterday. That’s roughly when our australopithecine ancestors were figuring out how to use stone tools. For context, Mount Etna has been erupting for about 500,000 years and we still call it active.
Then there’s the curious case of Cerberus Fossae. In 2017, researchers identified evidence of volcanic eruptions there within the past 50,000 years—practically last Tuesday by planetary standards.
Why Mars Refuses to Play by Earth’s Rules
Earth’s volcanoes exist because of plate tectonics, that constant churning of crustal plates that recycles rock and builds mountain chains. Mars never developed plate tectonics, or if it did, the system shut down billions of years ago. Instead, Martian volcanoes formed as magma punched through the same spot in the crust for millions of years, building upward like geological stalagmites. No plate movement meant no volcano migration—just relentless vertical growth.
This creates a perplexing situation.
Without plate tectonics to generate magma through subduction, where’s the heat coming from? The planet’s core should have cooled considerably by now. Yet something appears to be driving occasional volcanic activity, whether it’s residual heat from planetary formation, radioactive decay in the mantle, or some mechanism we haven’t identified yet. The math doesn’t quite add up, which either means our models are wrong or Mars is hiding something.
The Seismic Data That Changed Everything Recently
NASA’s InSight lander, which operated from 2018 to 2022, detected thousands of marsquakes. Many originated from Cerberus Fossae—the same region with young volcanic features. One quake in May 2022 registered magnitude 5, the largest ever recorded on another planet. The seismic waves revealed that Mars still has a partially molten core, roughly 1,800 kilometers in radius. That’s a lot of potential energy sloshing around beneath a supposedly dead surface.
InSight also detected something unexpected: seismic activity that looked suspiciously like magma movement. Not eruptions exactly, but the kind of deep rumbling that suggests molten rock is still on the move beneath certain regions. It’s the geological equivelent of hearing pipes clank in an supposedly abandoned house.
What This Means for Future Mars Explorers
If Martian volcanoes are merely dormant rather than extinct, that changes everything about future human settlements. Active volcanism means geothermal heat—a potential energy source. It also means volcanic gases that could be processed into breathable air or rocket fuel. But it also introduces risk. Imagine establishing a colony and then discovering you’ve built on top of a volcano that erupts every 50,000 years.
Turns out the Red Planet still has some geological fire in its belly.
The question isn’t whether Mars had active volcanoes—we know it did. The question is whether it still does, or whether we’re just catching the final gasps of a planetary cooling process that began 4.5 billion years ago. Either way, Mars refuses to be the simple, dead rock we once imagined. It’s more like a sleeping giant that occasionally mumbles in its sleep, keeping scientists perpetually unsure whether it’s about to wake up or slip into permanent silence.
