Volcanoes may have once been active on Mars, possibly warming the planet enough for liquid water to exist on the Martian surface for a short period of time.
Mars currently exhibits lake beds, dry river channels, and lake basins that provide evidence liquid water likely once flowed across the surface of the Red Planet. Investigation of the role of vulcanism on Martian geology may provide additional evidence for ancient water on Mars.
Sulfur dioxide gas, released by volcanoes, may have created conditions warm enough for liquid water to flow during several points in the history of the planet. These eras of warmth each lasted just a few tens of thousands of years before the planet cooled once more.
Billions of years ago, the Sun was cooler than today, further cooling the planet.
"These new climate models that predict a cold and ice-covered world have been difficult to reconcile with the abundant evidence that water flowed across the surface to form streams and lakes. This new analysis provides a mechanism for episodic periods of heating and melting of snow and ice that could have each lasted decades to centuries," James Head of Brown University said.
The atmosphere of Mars is too thin to currently support liquid water on the surface. Astronomers believe most of the liquid water on Mars flowed across the surface around 3.7 billion years ago, when volcanoes were far more active on the planet than they are in the modern day.
Volcanoes on Earth cool the planet, but Head and his team believe the sulfur dioxide emitted from eruptions on Mars may have trapped heat from the Sun, warming the globe. Researchers developed computer models that showed how Martian volcanoes may have warmed the planet, allowing water to run. These simulations suggested molecules of sulfur dioxide may have become attached to dust particles in the Martian atmosphere, allowing light to pass through the material. Warming caused by the greenhouse gas could then have raised temperatures enough for water to travel across the Martian landscape.
"Life in Antarctica, in the form of algal mats, is very resistant to extremely cold and dry conditions and simply waits for the episodic infusion of water to 'bloom' and develop. Thus, the ancient and currently dry and barren river and lake floors on Mars may harbor the remnants of similar primitive life, if it ever occurred on Mars," Head stated in a press release.
As vulcanism became less common on Earth, liquid water on the surface became impossible, leading to the arid desert world we see today.
Study of Mars, and how volcanoes may have once warmed the planet enough for liquid water to run was profiled in the journal Nature Geoscience.
