Most people know that Olympus Mons is the tallest mountain and volcano in the solar system, but its size is still difficult to fathom. Standing at a massive 25.7 kilometers (16 mi) high, this Martian monolith is just under three times the height of Everest and its base covers almost the same area as Arizona. Despite Olympus Mons’s massive height, though, it would be remarkably easy to climb, as the average slope is only a 5° incline.
But how did it get so big? Like volcanoes on Earth, Olympus Mons was formed due to cooling lava emerging from hot spots underground. However, unlike Earth, Mars doesn’t have a lot of tectonic motion, so these hot spots never shifted to a different location. The lava just kept building up in the same place until it became the beast of a mountain that is Olympus Mons. In fact, the volcano is so heavy that it actually sinks into the Martian surface, creating a moat around its base.
2. Pancake Domes (Venus)
Venus is often described as Earth’s sister planet, but a more accurate description would be Earth’s teenage sister, as the second rock from the Sun is volatile, uninhabitable, and hard to understand. Venus has more than 1,600 major volcanoes, and over 85 percent of its surface area is pure volcanic lava plains. However, most of these volcanoes aren’t your standard lava-spewing hills.
One unusual structure type is referred to as a pancake dome, which typically stand at just under 1 kilometer (0.6 mi) high and range between 22 kilometers (13 mi) and 65 kilometers (40 mi) in width. They are thought to be formed through an eruption of highly viscous lava and spread out evenly due to the high pressure present on Venus. Pancake domes are often seen in clusters but, disappointingly, a group of pancake domes is not called a “stack.”
Hahaha I swear for the longest time I thought it was just me and my crazy cousins who played that the-ground-is-lava-stay-on-the-rug game. Where did that even come from and how do kids from different continents end up playing the same silly game?