The MARS Pro AstroReality App experience is full of information to explore the deep history of Mars. By tapping the button on the bottom labeled ‘Normal’ and again the one that says ‘Elevation’, you get to our Ocean experience. Here you will see the moving shorelines of a drying global ocean, evidence of which we are mapping across the planet. Here is the story of the Martian ocean and how we know it existed.
Mars today is a polar desert. Its air is so thin that water can not exist on the surface without being boiled away at the freezing temperatures. But it used to be different. Trapped in the rocks of Mars is evidence of a wet world. We have seen river channels and deltas that could only be formed from rain and lakes. We see outflow channels that would have flooded half the planet and find evidence the other half absorbed an oceans worth of water into its very mineral structure.
One of the most exciting clues about the water that once existed on Mars is signs of ancient shoreline. The northern half of Mars is much lower than the southern half and would have formed a natural basin for any water on Mars. All around this basin, we find evidence of a shoreline. We see the erosional signs of lapping waves, we see river deltas at the same elevation across the hemisphere and even see signs of tsunamis that would have flooded the land when the ocean was hit by meteorites. All these events are recorded in the rocks of Mars that we have mapped from space. Each has been observed, debated and integrated into a global understanding of past oceans on Mars.
The story of water on Mars is not a simple one. It appears to have come and gone and returned again. We see evidence of oceans forming, draining to the atmosphere and ice deposits to flow again. More rovers, missions and observations will continue to build our understanding of this story and we will work to share it with you on the MARS Pro AstroReality App experience.