There are some things you just don’t think about until they’re shown to you. Most people don’t think twice about why the same side of the moon always faces us, it’s either just coincidence or divine intervention, but when you learn it’s a relatively simple aspect of gravity (tidal locking) you find yourself asking where else such things might occur. Likewise I had never really thought about why rivers tend to twist and turn, thinking that it was most likely because there were things in the water’s way that it was just getting around, but as it turns out there’s a very clear explanation for why they bend, even without objects being in their way:
Understanding these fundamental principles is what allows us to look at other places in the universe and draw conclusions about what they might have been like billions of years in the past. We’ve long speculated that Mars was once host to oceans and rivers not unlike our own based on ideas like this; their snake like remnants still being visible long after the water has departed. Hopefully one day we’ll find the ever elusive underground reservoirs of water on Mars and maybe, just maybe, find evidence of life that may have once played a role in shaping those long forgotten rivers.
