Tuesday, November 18, 2025

The True Size of the Solar System’s Largest Volcano Will Shock You.

This is Olympus Mons of Mars, the largest volcano of our solar system… Crazy Large.

Many don’t realise how big we're talking, so here is a comparison with Mount Everest and Mount Loa.

At approximately 25 km, it is three times higher than Mt Everest, which is only 8.8 km high.

Surprised? Let me tell you, this is nothing in front of its size comparison.

It’s almost the size of France with an area of 300,000 km², it's so wide that you wouldn't even know you're on a mountain.

And this large area also means that it is significantly harder to climb Everest than Olympus, mainly because it is a very gradual and wide volcano. Its average slope is only 5%.

But why does it even exist?

Except for the fact that possibly it once had lava flows 100× bigger than Earth’s, the most important reason is Mars’s gravity. Mars has only 38% of Earth’s gravity, and that allows structures to grow much taller without collapsing under their own weight.

But you know what’s the funny part, our initial understanding about this giant volcano was a “Snow-Capped Mountain”(1870s–1900s). We even named some bright patches Nix Olympica, which literally means “The Snows of Olympus”. It was mainly because of weak telescopes, and its enormous height also made it look brighter than the surroundings, which felt like snow.

And even today, the name is totally wrong; it literally came from a misidentification, which means “snow patch”… it sounds cool though.

Mariner 9 narrow angle camera of Olympus Mons' central caldera. (March 7, 1972)

This image by Mariner 9 aircraft was among the first images to confirm that Olympus Mons was a volcano.

Digital mosaic of Olympus Mons, taken by the Viking 1 Orbiter. (February 1, 2016)


Sources: science.nasa.govreddit.com

And there are hundreds of more interesting facts about this discovery that we can talk about, numerous findings that have improved our understanding of things over the years that we can dive into.