Three times larger than Everest... the mountain that broke the rules on Mars

 

Ever since the Italian astronomer Giovanni Schiaparelli observed the features of the surface of Mars in the nineteenth century, the volcanic region of Tharsis has continued to fascinate scientists.

But images captured by NASA's Mariner 9 spacecraft in 1971 revealed an astonishing truth: a colossal volcano had emerged, surpassing all other mountains on Earth in size and height. It was named Mount Olympus, becoming the tallest mountain and largest known volcano in the solar system.

Between Olympus and Everest

Comparison between Olympus Mons on Mars and Everest on Earth 

Mount Olympus rises approximately 22 to 25 kilometers above the surrounding plains, with a base diameter of nearly 600 kilometers, while its dramatic cliff face stretches for considerable distances encircling most of the mountain. Since then, Olympus has served as a natural laboratory for understanding the history of volcanic activity and the evolution of rocky planets.

The absence of tectonic plates gave the volcano millions of years to grow.

Planetary geologists believe that the biggest secret behind Olympus's enormous size lies in Mars' radical difference from Earth. On our planet, tectonic plates constantly move over the mantle, so the crust moves away from the hotspots that feed volcanoes, forming volcanic chains instead of a single giant volcano, as happened in the Hawaiian Islands.

The tallest mountain in our solar system is located on the surface of Mars. It is called Olympus Mons, and it has a diameter of 600 kilometers, occupying an area the size of the diameter of the yellow circle on Earth.

The highest mountain in our solar system is located on the surface of Mars, and it is called Mount Olympus. It has a diameter of 600 kilometers and occupies an area the size of the diameter of the yellow circle on the globe (Al Jazeera Documentary).

On Mars, however, there is no evidence of active tectonic plates like those on Earth. Therefore, the crust remained stable over the magma source for millions of years, and lava flowed over the same location repeatedly, layer upon layer, until the volcano reached an unprecedented size.

Studies by NASA and the U.S. Geological Survey indicate that this growth continued for very long periods, and the mountain may have experienced relatively late stages of activity compared to most Martian volcanoes.

Weak gravity and lack of erosion protected the mountain from collapsing.

Mars's geological features also contributed to Olympus's height. The planet's gravity is only about 38% of Earth's, allowing for the formation of taller mountains before they collapse under their own weight. Furthermore, relatively quiet volcanic activity, based on flows of low-viscosity basaltic lava, created a vast shield volcano similar to those in Hawaii, but one that grew over a much longer period.

Furthermore, Mars lacks permanent rivers, rain, oceans, and the active glacial movement that constantly carves mountains on Earth. Even Martian winds, while capable of transporting dust, lack the power to dislodge boulders the size of those created by water and ice on Earth.

Therefore, the lava layers have remained preserved for hundreds of millions of years, while the Earth's mountains are constantly subjected to erosion, landslides, and earthquakes that limit their height.