|This artist's depiction gives you an idea of how big this landmark is|
2. Valles Marineris is Latin for "Mariner Valleys." It's named after the Mariner 9 Mars orbiter (which sent back images of Mars from 1971–72).
3. There have been many hypotheses about what formed Valles Marineris. Was it carved by flowing water? Carbon dioxide ice glaciers? Maybe there was a massive melting of permafrost (underground water ice and carbon dioxide ice)? Was there magma under the surface that flowed somewhere else, causing a surface collapse? Were volcanoes involved? Or is it mostly rift faults, akin to Earth's East African Rift (formed as tectonic plates move apart)?
|Valles Marineris circled showing just how huge it is|
4. It reaches depths of up to 7 km. (The Grand Canyon gets about 1.6 km deep.)
5. It runs very near the equator of Mars.
|Imagine if it was filled with water...|
6. The western end is called Noctis Labyrinthus, the "labyrinth of the night." It's like a maze of valleys.
|Western Valles Marineris, image courtesy of NASA/JPL-Caltech|
7. Huge landslides have happened on the canyon walls, carrying material more than halfway across the bottom of the canyon
|Aerial shot of a massive landslide|