The Island Origins of Mars' Olympus Mons Volcano

Researchers at the French National Centre for Scientific Research (CNRS) and Université Paris-Saclay have suggested that Mars' Olympus Mons, the largest volcano in the solar system, was once a volcanic island surrounded by an ancient northern ocean. The study found morphological similarities between Olympus Mons and volcanic islands on Earth, and identified an escarpment at the base of the volcano that is similar to those formed by lava flowing into surrounding ocean water. The researchers also found similar characteristics in another volcano, Alba Mons, suggesting that the ancient ocean covered much of Mars' northern hemisphere.