Washington: A new study has revealed that volcanism and greenhouse gas could have warmed Mars sufficiently, but only for tens or hundreds of years at a time, which could have triggered water flow.
The study, by scientists from Brown University and Israel's Weizmann Institute of Science, suggests that warmth and water flow on ancient Mars were probably episodic, related to brief periods of volcanic activity that spewed tons of greenhouse-inducing sulfur dioxide gas into the atmosphere.
The work, which combines the effect of volcanism with the latest climate models of early Mars, suggests that periods of temperatures warm enough for water to flow likely lasted for only tens or hundreds of years at a time.
The latest generation of climate models for early Mars suggests an atmosphere too thin to heat the planet enough for water to flow. The sun was also much dimmer billions of years ago than it is today, further complicating the picture of a warmer early Mars.
James W. Head, professor of earth, environmental and planetary sciences at Brown University and co-author of the new paper with Weizmann's Itay Halevy, said that 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 and the new analysis provides a mechanism for episodic periods of heating and melting of snow and ice that could have each lasted decades to centuries.
The researchers created a model of how sulfuric acid might react with the widespread dust in the Martian atmosphere and the work suggests that those sulfuric acid particles would have glommed onto dust particles, which would reduce their ability to reflect the sun's rays. Meanwhile sulfur dioxide gas would produce a modest greenhouse effect - just enough to warm the Martian equatorial region so that water could flow.
The study was published in Nature Geoscience.