Original photo by SciePro/ Shutterstock
Earth is home to stunning snow-capped mountains that tower over their surrounding landscapes, but none quite compare to Mars’ Olympus Mons. First photographed in detail by NASA’s Mariner 9 probe in 1971, Olympus Mons (Latin for “Mount Olympus”) is nearly 16 miles tall. For comparison, its most famous Earthly competitor — Mount Everest — is only about 5.5 miles above sea level. The width of Olympus Mons is just as impressive as its height: Stretching 374 miles across, it’s as big as the entire state of Arizona. Olympus Mons is what’s known as a shield volcano — a type formed as lava slowly spreads out and cools; they usually have a low profile and are named for their resemblance to a warrior’s shield.
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It's a fibIo, a moon of Jupiter, is the solar system’s most volcanically active spot, with hundreds of volcanoes erupting every moment. The tiny moon is influenced by the gravity of Jupiter and sibling moons, which create tides and friction that heat it and cause major volcanic activity.
So how did Olympus Mons get so big? Scientists think a combination of low surface gravity and high volcanic activity allowed Mars’ great shield volcano to grow — over billions of years — beyond anything seen on Earth. And unlike on Earth, where volcanoes form as tectonic plates drift over hot spots of lava, Mars’ plate movement is much more limited, meaning magma can build and build in one spot over a long time. So while summiting peaks like Everest and K2 remains an impressive terrestrial feat, the solar system’s biggest climbing challenge awaits on the red planet.
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The ______ islands would fit inside Mars’ Olympus Mons volcano.
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The Hawaiian islands would fit inside Mars’ Olympus Mons volcano.
In the 19th century, some people thought there were alien-made canals on Mars because of a translation error.
In 1877, astronomer Giovanni Schiaparelli — director of the Brera Observatory in Milan — began mapping the surface features of Mars. Among these features were what Schiaparelli called canali, or what appeared to be channels on the Martian surface. While these “channels” were little more than an illusion created by the alignment of craters and other surface features — all obscured by the poor resolution of 19th-century telescopes — English-speaking publishers translated canali as “canals,” a shift that encouraged interpreting them as something made by an intelligent being. In the 1890s, American astronomer Percival Lowell ran with this idea and argued that these alien-made “canals” were built to transport water from Mars’ ice caps. The theory captured the imagination of the public — H.G. Wells even wrote his famous novel “War of the Worlds” during this “canal craze.” While plenty of scientists were skeptical of Lowell’s theories, the matter wasn’t definitively put to rest until 1965, when NASA’s Mariner 4 space probes took a closer look. No canals were found, but what they discovered — the gargantuan volcano Olympus Mons, for one — was just as incredible.
Darren Orf lives in Portland, has a cat, and writes about all things science and climate. You can find his previous work at Popular Mechanics, Inverse, Gizmodo, and Paste, among others.
