New York, Nov 18: New research finds that warmth and water flow on ancient Mars were probably episodic, related to brief periods of volcanic activity that spewed tons of greenhouse-inducing sulphur dioxide gas into the atmosphere.
The work by scientists from Brown University in Rhode Island and Israel's Weizmann Institute of Science 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.
"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," said James W. Head, professor of earth, environmental and planetary sciences at Brown University.
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 team explored the idea that heating may have been linked to periodic volcanism.
"We found that volcanism can bring the temperature on early Mars above the melting point for decades to centuries, causing episodic periods of stream and lake formation," Head added.
Ample evidence of ancient rivers, streams and lakes make it clear that Mars was at some point warm enough for liquid water to flow on its surface.
The new research was published in the journal Nature Geoscience.