This canyon is called Valles Marineris, and it's truly massive:
* Length: Around 2,500 miles (4,000 kilometers) - four times longer than the Grand Canyon!
* Depth: Up to 7 miles (11 kilometers) deep
* Width: Ranges from 2 to 200 miles (3 to 320 kilometers)
It's so big, you could fit the entire state of Arizona inside it!
