Mars – We often marvel at the largest peaks that grace our planet—Everest, K2, Denali—but there is a mountain that dwarfs all these giants not just by a little, but by an astronomical margin. Olympus Mons, is the largest volcano in our solar system. It’s located not on Earth, but on Mars.
Olympus Mons stands at a staggering height of about 22 kilometers (13.6 miles) with a base diameter of approximately 600 kilometers (373 miles). To put that into perspective, Mount Everest, Earth’s highest peak at approximately 8.8 kilometers (5.5 miles), is nearly 2.5 times shorter than Olympus Mons. The sheer scale of this Martian giant is not just impressive in terms of its height but also in its volume and area. Olympus Mons covers an area similar to the size of Arizona or Italy!

This shield volcano has a gently sloping base, a characteristic common to the shield volcanoes of the Hawaiian Islands on Earth, but on a much vaster scale. Its massive size is due to the lack of plate tectonics on Mars, which allows the volcano to accumulate layers of lava over millions of years without interruption. The caldera at the summit of Olympus Mons is about 80 kilometers (50 miles) wide, which could comfortably accommodate the entirety of Paris.

If Olympus Mons were to be placed on Earth, it would not only tower over the highest peaks but also dramatically alter the Earth’s geography and climate. For example, superimposing it onto the United States map, it would cover a significant portion of the western states, providing a surreal and formidable sight.