New evidence shows Mars had a watery past

Washington, Dec 19 (ANI): A research team has found evidence of carbonates on Mars, which are long-sought minerals that shows the Red Planet was home to a variety of watery environments in its ancient past.

Recent observations from the Mars Phoenix lander and other spacecraft show that the planet still holds vast deposits of water as ice at its poles and in soil-covered glaciers in the mid-latitudes.

What is less known is how much water occupied the red planet and what happened to it during its geological march to the present.

Mostly, evidence has pointed to a period when clay-rich minerals were formed by water, followed by a drier time, when salt-rich, acidic water affected much of the planet.

Assuming that happened, it would have been difficult for life, if it did exist, to have survived and for scientists to find traces of it.

Now, a research team led by Brown University has found evidence of carbonates, a long-sought mineral that shows Mars was home to a variety of watery environments - some benign, others harsh - and that the acidic bath the planet endured left at least some regional pockets unscathed.

If primitive life sprang up in pockets that avoided the acidic transformation, clues for it may remain.

"Primitive life would have liked it," said Bethany Ehlmann, a Brown graduate student and lead author of the research paper. "It's not too hot or too cold. It's not too acidic. It's a 'just right' place," Ehlmann added.

Finding carbonates indicates that Mars had neutral to alkaline waters when the minerals formed in the mid-latitude region more than 3.6 billion years ago.

Carbonates dissolve quickly in acid, therefore their survival challenges suggestions that an exclusively acidic environment later cloaked the planet.

The carbonates showed up in the most detail in two-dozen images beamed back by the Compact Reconnaissance Imaging Spectrometer for Mars, an instrument aboard the NASA Mars Reconnaissance Orbiter.

The latest observations indicate carbonates may have formed over extended periods on early Mars and also point to specific locations where future rovers and landers could search for possible evidence of past life.

"This is opening up a range of environments on Mars," said John Mustard, a Brown professor of geological sciences. "This is highlighting an environment that to the best of our knowledge doesn't experience the same kind of unforgiving conditions that have been identified in other areas," he added.

According to Mustard, "We can say pretty confidently that when water was present in the places we looked at, it would have been a happy, pleasant environment for life." (ANI)