What if a volcano grew for billions of years, completely unchecked?
On Mars, that actually happened. Olympus Mons is the tallest known volcano in the solar system — rising about 22 kilometres above the Martian surface. That's roughly two and a half times the height of Mount Everest. And its base stretches around 600 kilometres across, wide enough to swallow an entire country. If you stood at its edge, you wouldn't even be able to see the summit — it's simply too vast. The reason it got so enormous comes down to two things: Mars has lower gravity than Earth, and its crust doesn't shift the way ours does. On Earth, tectonic plates drag the crust away from hotspots, cutting off a volcano's fuel supply. On Mars, the crust sat still, and the lava just kept piling up over billions of years. One planet, one spot, one extraordinary mountain. Follow Deep Field Vault for more of the solar system's strangest truths.