Spiral troughs found on the surface of Mars are in situ ice-excavated canyons with a total volume 10 times that of the Grand Canyon, making them one of the largest and youngest geologic mega-structures in the Solar System, a new paper by Planetary Science Institute Senior Scientist Alexis Palmero Rodriguez says.
Click here for original story, Huge Spiral Troughs on Mars are Young, Formed by Erosion
Source: Mars News