Where Did Mars's Water Go? The Picture Is Getting Clearer.

The article focuses on recent scientific studies addressing the disappearance of water from Mars. One study, using data from the Mars InSight lander, found evidence of a subsurface layer containing enough water to cover Mars with an ocean about a mile deep. Another study, analyzing hydrogen escape data from NASA’s MAVEN orbiter and the Hubble Space Telescope, showed that significant amounts of water were lost to space over billions of years, particularly during Mars’s closest solar approaches due to its elliptical orbit. Together, these findings suggest that Mars’s water both retreated underground and escaped into space, with current estimates indicating that tens to hundreds of meters of water have been lost to space while much remains frozen or trapped below the surface.