Everest isn't the solar system's tallest mountain—prepare to rethink everything you know about planetary peaks with Olympus Mons!
Imagine standing on the edge of a Martian landscape, gazing at a colossal structure that dwarfs even our planet's mightiest summits. Tucked away at the western fringes of Mars's equatorial highlands, this enormous geological wonder stretches far into the planet's wispy atmosphere. It's unlike anything on Earth, with no active counterparts anywhere else in our solar system. For years, it's embodied the extremes of planetary science—immense, serene, and virtually untouched by change.
From space, it doesn't look much like a traditional mountain; instead, it resembles a vast shield blanketing the Martian terrain. High-definition images reveal a summit that's strikingly level and sides that slope with unexpected gentleness. It doesn't throw dramatic shadows or show obvious signs of recent upheaval. Yet beneath this calm exterior lies a rich, ongoing tale of geological transformation that's just starting to unfold.
And this is the part most people miss... Only in recent times have experts in planetary geology begun to probe its depths with greater accuracy. Thanks to advanced imaging and topographic models from missions like Mars Express and the Mars Reconnaissance Orbiter, we're uncovering layers of history that upend old ideas about Mars and the forces that molded it. The mountain's beginnings, its sheer scale, and its current state spark questions that go way beyond just Martian rocks—they challenge how we view planetary evolution.
Dubbed Olympus Mons, this giant isn't just big; it's redefining what we consider volcanic. While its dimensions are impressive, the secrets it holds about how planets behave without the constant grind of tectonic plates are what truly captivate scientists today.
A volcano that shatters records
Olympus Mons claims the title of the solar system's tallest volcano. Soaring about 26 kilometers above the surrounding Martian plains, it towers nearly three times higher than Mount Everest. Its foundation sprawls over 600 kilometers, bigger than the entire country of Poland—that's roughly the distance from New York to Chicago!
We've known about its enormity for a while, but fresh insights from orbiting spacecraft are shedding light on how it grew so enormous. Its development ties directly to Mars lacking plate tectonics, unlike Earth where continents drift and volcanoes pop up in new spots over time.
On our dynamic planet, tectonic plates shift, spreading out volcanic activity across the globe. But Mars has a stationary crust, meaning Olympus Mons erupted in one spot over a hotspot that stayed put. Lava piled up relentlessly for eons, spilling outward and upward without being diverted by moving landmasses. Instead of a string of smaller volcanoes, we got this single, mammoth structure. Think of it like a giant lava lamp that just kept flowing without interruption, building a mountain that's hard to comprehend.
Data from NASA also highlights its gentle incline, averaging just 5 percent—think of a highway ramp rather than a steep cliff. From the lower slopes, you might not even realize how high you're climbing; the peak would vanish over the horizon due to the gradual curve. It's a beginner-friendly reminder that not all mountains scream their height—some whisper it through subtle slopes.
Preserved by a quiet, airless world
The volcano's sides feature broad lava fields dotted with channels, terraces, and smooth expanses. At the footing, a sheer drop-off called an escarpment plunges up to 6 kilometers into a surrounding trench, like a moat around a castle. Experts believe this formed as the mountain's weight sank into the Martian crust, creating a basin that highlights the ongoing interplay between mass and surface.
At the top, six interconnected calderas—crater-like pits from drained magma chambers—stretch almost 80 kilometers. These point to a history of repeated eruptions. Images from the European Space Agency reveal lava flows that could be as young as two million years old, suggesting the volcano might still have some fire left in it.
Mars's arid climate and thin air act like a natural time capsule, keeping these features sharp. No heavy rains or strong winds to wear them down, so ancient flows, landslides, and layers stand out clearly. It's preserved better than many Earth volcanoes, where erosion quickly obscures the past.
Lately, we've spotted hints of frost and even possible rock glaciers near the summit. ESA pictures show curled, ridged shapes reminiscent of icy formations on our planet. These might trap water ice under rocky debris, dating back just a few million years—far fresher than expected for such an old world.
In 2024, Sky at Night Magazine reported seasonal frost on the upper slopes equal to about 60 Olympic-sized swimming pools' worth of ice. While temporary, these deposits hint at how Olympus Mons interacts with Mars's modern weather patterns, adding a layer of dynamic activity to its story.
A volcano with a marathon lifespan
How long has Olympus Mons been erupting? That's another puzzle drawing attention. Counting impact craters on its surface suggests some parts are geologically young, while other evidence points to activity stretching over two billion years—longer than most Earth volcanoes, which fizz out after a few million years.
Researchers at the University of Glasgow studied Martian meteorites called nakhlites, which seem to have erupted over 90 million years. This endurance is rare on Earth, where volcanoes often tie to short-lived hotspots. On Mars, the steady source of magma allowed for prolonged, patient growth.
Lava analyses from the Mars Reconnaissance Orbiter show diverse ages and chemistries. Some flows have defined channels with levees, like rivers of cooled lava, indicating slow, oozing eruptions from low-viscosity magma. This style builds mountains steadily, without the explosive drama of many Earth volcanoes—for beginners, think of it as a gentle melt rather than a fiery blast.
The surface is mostly basaltic rock, packed with iron and magnesium—explaining why Mars looks red from all that iron oxide. A Wikipedia breakdown notes about 44% silicates and over 17% iron oxides in its makeup, painting a picture of low-viscosity flows that spread wide and built tall.
Barriers to boots on the ground, but exploration marches on
Despite its allure, Olympus Mons is off-limits for landers or rovers right now. At such heights, Mars's thin atmosphere thins further, making parachute landings tricky and rover wheels prone to sinking in the dusty soil. Navigation would be a nightmare in this loose terrain, where stability is a luxury.
Still, excitement is building. In 2021, a team from Sweden's Royal Institute of Technology pitched a human mission idea, the Mount Olympus Mons Ascension Mission, blending robotic scouts with partial human hikes by 2042. They outlined basics for climbing gear and life support in Mars's high-altitude thin air—imagine adapting Everest tech but for a planet with 1% of Earth's atmosphere!
Private ventures like 4th Planet Logistics are crafting virtual climbs using real topo data, letting people 'experience' the ascent from home. These efforts not only educate but also democratize the wonder of Olympus Mons.
For now, orbiting probes provide our best glimpses. Mars Express and MRO's cameras and sensors deliver detailed maps, tracking its growth, layers, and subtle signs of life. But here's where it gets controversial... Some scientists debate if Olympus Mons is 'active' or just dormant, questioning whether we've missed recent eruptions due to Mars's thin air suppressing visible signs. Does this mean it's safer to explore, or riskier? And could its long history challenge our views on planetary 'death,' suggesting Mars isn't as dead as we think?
What do you think? Should we invest in a real climb of Olympus Mons, or keep it as a remote marvel? Do the controversies about its activity change how we prioritize Mars missions? Share your opinions in the comments—let's discuss!
