Fluvial mapping of Mars

It took fifteen years of imaging and nearly three years of stitching the pieces together to create the largest image ever made, the 8-trillion-pixel mosaic of Mars' surface. Now, the first study to utilize the image in its entirety provides unprecedented insight into the ancient river systems that once covered the expansive plains in the planet's southern hemisphere.

source https://www.sciencedaily.com/releases/2020/12/201222141526.htm