The history of liquid water on Mars is of great interest because water would have strongly influenced the planet’s climate and its potential for habitability. Evidence for a watery past in Mars’s geological record is abundant, but many of the data are indicative of catastrophic outflows or intermittent releases that neither require a temperate surface environment, nor are thought to have persisted long enough for the development of microbial life.
Those claiming that Mars never had oceans of liquid water often point to the fact that estimates of the size of the oceans don’t jibe with estimates of how much water could be hidden today as permafrost underground and how much could have escaped into space. These are the main options, given that the polar ice caps don’t contain enough water to fill an ocean. Researchers developed a much more cohesive model for early geologic evolution on Mars by shifting around the timing of major events, specifically the formation of Tharsis, Mars' largest volcanic feature. The new models of ocean formation on Mars suggest Tharsis and its development strongly influenced the Red Planet's watery past. The volcano's release and greenhouse gases likely created a warmer climate, allowing water to exist in liquid form. Eruptions also likely created cavities through which water could flow to the surface. By no means is the new explanation for Mars' oceans a certainty, but the new theory offers scientists new ideas to test.
By: Swati Kaushal