
Well, OK, technically it’s the mantle, not the crust.
But it is thick. Super thick. And no gradations like the Earth.
Extrapolating to the known surface geology of the rest of the planet, this suggests an average thickness of between 24km and 72km. By contrast, Earth’s average crustal thickness is 15-20km.
https://www.bbc.com/news/science-environment-57935742
So what does this mean?
For one thing, it probably explains why there’s no breathable atmosphere on Mars.
Mars never developed a global magnetic field to block solar radiation. So it’s atmosphere was basically ripped right off.
And any terraforming attempts in the future would fail on a global scale. But maybe locally it might work…