Para onde foi a água de Marte?

https://www.gizmodo.com.au/2017/12/this-could-be-where-mars-water-disappeared-to/
Citando:
"The group began by creating analytical models, based on data from sources including the Martian rovers. That required calculating the details of each planet's mantle temperatures and pressures and estimating their early rock compositions, among other factors. Playing each model forward in time revealed that Mars' smaller size and its increased level of iron would send way more water into its mantle. Earth's more buoyant crust and steeper increase in temperatures at increasing depth in its early history could have further prevented water from reacting with the mantle. The researchers published their results today in the journal Nature."