Giant Mars mountain Olympus Mons may once have been a volcanic island
Giant cliffs that encircle Olympus Mons formed when lava flowing down the volcano encountered deep water.
![](https://kbin.cafe/media/cache/resolve/entry_thumb/48/68/48687732ef88164948671d84dc2fdd237f17e5688b8c3b8b89e75980f9ce3e82.jpg)
Giant cliffs that encircle Olympus Mons formed when lava flowing down the volcano encountered deep water.