What would Mars look like with Water?

The concept of Mars with water is a subject of both scientific inquiry and popular imagination, especially given the various pieces of evidence suggesting that Mars once had flowing water and possibly even oceans.  While we can only speculate based on current understanding, here’s a glimpse into what Mars might look like if it had substantial amounts of water:

Visual Features

• Blue Skies:  One of the first noticeable differences would be the color of the sky.  The sky on Mars is currently a dusty pinkish-red due to the scattering of sunlight by the planet’s thin atmosphere.  A thicker atmosphere accompanying bodies of water might shift the sky’s hue closer to blue, much like Earth’s.
• Oceans and Seas:  If Mars had enough water to form oceans or large seas, the landscape would be dramatically different.  Some scientists speculate that an ancient Martian ocean could have covered the planet’s northern hemisphere.  In a modern context, this would mean vast expanses of blue in the northern regions.
• Rivers and Lakes:  Features like Valles Marineris and the various canyons and channels on Mars would likely be filled with flowing water.  What are now dry riverbeds and lake basins would become vibrant waterways and water bodies, adding complexity to the Martian landscape.
• Clouds and Weather Patterns:  With a significant amount of water, Mars would experience a more dynamic weather system.  Clouds would become a common sight, and precipitation would alter the appearance of the terrain, possibly leading to seasonal changes similar to those on Earth.

Ecological Possibilities

• Potential for Life:  With stable bodies of water, the potential for life as we know it would greatly increase.  Whether microbial life or more complex organisms, water bodies would provide the necessary environment for life to take root.
• Vegetation:  If the conditions were right, we could expect to see some form of plant life. Even simple mosses or algae would dramatically change the appearance of the planet, adding shades of green to the predominantly red landscape.

Geographical Changes

• Shorelines and Beaches:  The sharp dichotomy between the low northern plains and the higher southern highlands would become more evident as the boundary between land and water.  You would expect to see natural beaches and maybe even cliffs.
• Ice Melt:  If Mars were to have liquid water, it would mean the polar ice caps would be melting at least seasonally, feeding into the global water system and possibly creating a polar sea or large lakes.

Theoretical Challenges

• Atmospheric Pressure:  For water to exist in a liquid state, Mars would need a thicker atmosphere to increase surface pressure. This would also affect the planet’s overall appearance.
• Temperature:  Mars is quite cold, with average temperatures around -80 degrees Fahrenheit (-62 degrees Celsius). For liquid water to be stable, the planet would need a mechanism to retain heat, possibly through a stronger greenhouse effect.

Check out our 3D Mars Learning Center for more information on Mars.   You can also learn more at: NASA Mars Exploration.