Olympus Mons isn’t just big—it’s absurdly big. This Martian shield volcano is 22 km (13.6 miles) high, nearly three times the height of Mount Everest. Its base is as wide as France. If you stood at its summit, the curve of Mars itself would block your view of the ground. The reason it got so big? Mars doesn’t have active plate tectonics like Earth, so the volcano could keep erupting in the same spot for millions of years, piling up layer after layer of rock.
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