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"Climate on Early Mars May Have Been Very Similar to Antarctica"

 

 

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"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," says James W. Head, professor of earth, environmental and planetary sciences at Brown University. "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."

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. While that may conjure up images of a tropical Martian paradise, new research published today in Nature Geoscience throws a bit of cold water on that notion.

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.

With all that's been learned about Mars in recent years, the mystery of the planet's ancient water has deepened in some respects. 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 Head,and co-author of the new paper with Weizmann's Itay Halevy. "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."

Halevy and Head explored the idea that heating may have been linked to periodic volcanism. Many of the geological features that suggest water flow date to around 3.7 billion years ago, a time when massive volcanoes are thought to have been active and huge lava outpourings occurred. On Earth, however, widespread volcanism often leads to cooling rather than warming. Sulfuric acid particles and thick ash reflect the sun's rays, and that can lower temperatures. But Head and Halevy thought the effects of sulfur in Mars' dusty atmosphere might have been different.

To find out, the researchers created a model of how sulfuric acid might react with the widespread dust in the Martian atmosphere. 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.

Head has been doing fieldwork for years in Antarctica and thinks the climate on early Mars may have been very similar to that of the cold, desert-like McMurdo Dry Valleys. The image below shows the U.S. Antarctic Program field camp at Lake Hoare in the McMurdo Dry Valleys, with the Canada Glacier in the background. (Peter West/National Science Foundation)

 

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"The average yearly temperature in the Antarctic Dry Valleys is way below freezing, but peak summer daytime temperatures can exceed the melting point of water, forming transient streams, which then refreeze," Head said. "In a similar manner, we find 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."

But as that early active volcanism on Mars ceased, so did the possibility of warmer temperatures and flowing water.Head said the research may offer new clues about where the fossilized remnants of life might be found on Mars, if it ever existed.

The Daily Galaxy via Brown University

Image credit: NASA artist image of glaciers on Mars

Comments

Mars is a dead planet. Whatever nitrogen/oxygen/etc. atmosphere it may have generated in it's early forming was whisked away because of the planet's weak gravity. In addition, it does not have a molten core (which makes it similar to our moon), that could supply the necessary gases needed to support life. Any speculation about "life" on Mars is just poppycock.

LoL, that is just funny. Anartica has so much flowing water I can see the simularties

and NO the gravity did NOT cause the atmosphere to be whisked away, if that was the case then titan would have no atmosphere. It has no atmosphere because it has no large moon and therefore no magnetic field and the cosmic wind from the sun has "eroded" the atmosphere

Mars is a dead planet. Total waste of time and money sending rovers or anything else there. Spend the money on missions to Europa, Enceladus and Titan.

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