Olympus Mons: The Largest Volcano in the Solar System
Thursday, April 13, 2025 | Science | 6,092 Views

Olympus Mons, a colossal volcano on Mars, holds the title of the largest volcano in the entire solar system. Standing three times taller than Mount Everest and covering an area as vast as France, this Martian giant continues to captivate scientists and space enthusiasts alike.

The Majestic Olympus Mons on Mars

Olympus Mons, located in the Tharsis Montes region near the Martian equator, is a monumental feature on the surface of the Red Planet. Towering at 16 miles (25 kilometers) above the surrounding plains, this volcano is three times as tall as Earth's highest peak, Mount Everest, which stands at 5.5 miles (8.8 kilometers) above sea level. Its base stretches 374 miles (601 kilometers) across, roughly the size of the state of Arizona, making it one of the most striking geological formations in the solar system.

In comparison to Earth’s tallest volcano, Mauna Loa in Hawaii, which rises 6.3 miles (10 kilometers) above the ocean floor (with a peak elevation of only 2.6 miles above sea level), Olympus Mons is exponentially larger in both height and volume. The volume of Olympus Mons is about 100 times that of Mauna Loa and the entire Hawaiian Island chain could fit inside this Martian giant.

On Mars, scientists define the "sea level" using the areoid, an imaginary sphere based on the planet’s average equatorial radius. Although Olympus Mons stands at 13 miles (21 kilometers) when measured relative to this standard, it is still the tallest volcano known to exist in the solar system.

Unlike Earth’s steep mountains, Olympus Mons has a gentle, broad slope. If you were standing on its surface, it would appear more like a vast, gently sloping plain, despite its massive height. The volcano is a type of shield volcano, meaning it was formed by slow-moving lava that spreads out over large distances, creating a wide, shield-like shape with an average slope of just 5 percent.

A Relatively Young Volcano

While Olympus Mons has been forming over billions of years, parts of it are relatively young in geological terms, with the most recent eruption likely occurring as recently as 25 million years ago. This suggests that the volcano may still be active, with a potential for future eruptions. In fact, scientists believe there may still be some geothermal activity beneath its surface.

The summit of Olympus Mons features six collapsed calderas, which form a wide depression at the top of the volcano, spanning 53 miles (85 kilometers) in diameter. These calderas were likely created when magma chambers beneath the volcano emptied out during volcanic activity, causing the surface to collapse in on itself. A towering cliff, or escarpment, surrounds the volcano, rising as high as 6 miles (10 kilometers) above the surrounding plains. This escarpment alone is about as tall as Mauna Loa, further highlighting the immense scale of Olympus Mons.

The volcano’s massive weight has also caused the Martian crust beneath it to depress, creating a wide depression around its base. Scientists continue to study this fascinating structure to understand the geological processes at work on Mars.

Why Is Olympus Mons So Huge?

The enormous size of Olympus Mons can be attributed to a combination of factors unique to Mars. One key difference between Mars and Earth is the lower surface gravity of the Red Planet. This allows lava to build up higher before it begins to collapse under its own weight. Additionally, Mars lacks tectonic plate movement, which prevents the lava from shifting to new locations as it does on Earth. On Earth, hot spots of magma create volcanic islands over time, as seen with the Hawaiian Islands. However, on Mars, the stationary crust allows lava to accumulate in one spot, leading to the formation of massive volcanoes like Olympus Mons.

The extended lifespan of Martian volcanoes is another contributing factor. Unlike Earth’s volcanoes, which typically remain active for only a few million years, volcanic features on Mars can remain active for much longer periods. Studies of Martian meteorites have shown that Mars' volcanoes were active for over 2 billion years, with a steady plume of magma continuing to rise from beneath the surface. This stability and the slow accumulation of lava over time have allowed Olympus Mons to grow to such an incredible size.

Recent Discoveries and Active Geothermal Activity

Some regions of Olympus Mons may be as young as just a few million years old. Evidence of rock glaciers — rocky debris frozen in ice — suggests that ice may exist at the top of the volcano. This ice could be insulated by surface dust, and scientists believe that some of these glaciers could be as young as 4 million years old.

This discovery raises intriguing possibilities for the future of Mars exploration. The presence of ice on Olympus Mons suggests that there may be significant geothermal activity beneath the surface, potentially providing a resource for future Martian missions. The prospect of volcanic activity, along with evidence of ice deposits, makes Olympus Mons an essential target for scientific research in the coming years.

Exploring Olympus Mons

While Olympus Mons is not currently the focus of any active rover missions, scientists continue to study it using satellite imagery and high-resolution terrain models created by the European Mars Express orbiter. These models help scientists better understand the structure and formation of the volcano and its surrounding region. In fact, some students from the Royal Institute of Technology in Stockholm, Sweden, have already proposed a mission that could see humans travel to Olympus Mons in the next couple of decades. Their plan involves a rover taking explorers close to the summit of the volcano, where two individuals would complete the final climb on foot.

Additionally, a company called 4th Planet Logistics, which specializes in designing habitats for space exploration, has proposed the creation of a virtual-reality climbing route for Olympus Mons. This would allow people to explore the summit of the volcano remotely, offering an immersive experience of one of the most impressive features in the solar system.

In the future, if Mars tourism becomes a reality, Olympus Mons could become one of the most sought-after destinations for adventurers and space enthusiasts alike. Though physically reaching the summit may be challenging due to Mars' thin atmosphere and loose surface dust, virtual tours and rover missions could allow us to explore this magnificent volcano in ways never before imagined.