Mars once had water warm enough to sustain life
2012 11 19
By George Dvorsky | io9.com
We know that Mars once had lots of water, considered a prerequisite for habitability. What hasn’t been known, however, is just how friendly — or unfriendly — this water might have been to life, as the temperature and chemical conditions of ancient Martian water has remained a complete mystery.
But as a new analysis of Martian meteorites has revealed water temperatures on the Red Planet once ranged between 50°C to 150°C (122°F to 302°F) — temperatures that we know are most certainly hospitable to microbial life.
Biologists who study extremophiles on Earth have discovered many microorganisms that can survive and thrive in some of the most extreme environments. As an example, microbes have been found in the volcanic thermal springs at Yellowstone Park — water sources that, as we now know, are comparable in temperature to what was once found on Mars.
To make this determination, John Bridges from the University of Leicester Space Research Centre, took a closer look at a special class of Martian meteorites found only in impact craters. Called nakhlites, these rocks are characterized by an intricate series of small veins which are filled with minerals formed by the action of water near the surface of a planet.
By using an electron microscope and a transmission electron microscope, Bridges and his colleagues studied the peculiar alterations found in eight different samples. They discovered that the first mineral to grow along the walls of the vein was iron carbonate, which would have been formed by carbon dioxide-rich water at around 150°C. Then, after cooling to about 50°C, it formed clay minerals, followed by an amorphous phase that gave it the same composition as clay.
Fascinatingly, microbes use these exact reactions during mineral formation to gain energy and elements required for their survival.
"The mineralogical details we see tell us that there had been high carbon dioxide pressure in the veins to form the carbonates," noted Bridges through the official release. "Conditions then changed to less carbon dioxide in the fluid and clay minerals formed. We have a good understanding of the conditions minerals form in but to get to the details, chemical models are needed."
And indeed, subsequent analysis by Susanne Schwenzer, Postdoctoral Research Associate in the Department of Physical Sciences at The Open University, confirmed that this order-of-operations in mineral formation was what truly happened. As a result, Bridges and Schwenzer were able to predict water conditions on Mars. At first, the water was around 150°C and contained a lot of CO2 (forming the carbonates), and then cooled to about 50°C (thus forming the clays).
Interestingly, the driving force responsible for heating the water would have likely been asteroid impacts on the surface. Given just how pockmarked the planet is, there’s a good chance that Mars once featured many of these warm reservoirs.
The entire study can be found at Earth and Planetary Science Letters.
Article from: io9.com
Spidery black objects on Mars surface raise speculation
Weather On Mars Surprisingly Warm, Curiosity Rover Finds
Mars rover Curiosity finds signs of ancient stream
Mystery Spheres on Mars Baffle Scientists
Latest News from our Front Page
NATO increases military presence on Russia’s borders
The Pentagon has confirmed the military buildup along Russia’s borders to ensure long-term “peace and stability” in the region.
Earlier Moscow accused NATO of a sharp increase in air activity and intelligence flights in the border zone.
Replying to RIA Novosti’s query on the increased number of NATO flights around Russia’s borders, a Pentagon representative told the news agency that the military ...
US-Cuba ties thaw, White House open to Castro visit
A US visit by Cuban President Raul Castro is a possibility, the White House said, a day after he and US President Barack Obama announced a historic bilateral rapprochement.
With developments proceeding apace, a high-level US diplomat, Assistant Secretary of State Roberta Jacobson, revealed she will travel to Havana in late January for the first direct talks to "begin the process ...
Scientists Find Evidence of Viking Presence in Arctic Canada
A small stone artifact recovered from a Paleo-Eskimo site on Baffin Island is important evidence of a Viking presence in Arctic Canada around 1000 CE, says a team of scientists led by Dr Patricia Sutherland of the University of Aberdeen, Scotland.
The ancient site, called Nanook, was first discovered in the 1960s by Dr Moreau Maxwell of Michigan State University.
Three views ...
Washed up Viking anchors leads to project digging up the ‘Spanish Vikings’
The fearsome reputation of the Vikings has made them the subject of countless exhibitions, books and films – however, surprisingly little is known about their more southerly exploits in Spain.
No comprehensive archaeological study of Viking sites in Spain has ever been carried out and now a University of Aberdeen researcher plans to dig up the ‘Spanish Vikings’ for the first ...
Pentagon launching missile defense blimps to patrol East Coast
The US Army is set to begin testing its blimp-like surveillance airships, designed to help the military detect and destroy cruise missiles from attacking the nation’s capital and other East Coast cities.
The blimps at the center of the tests in Maryland are unmanned, 80-yard long, helium-filled aircraft that can float up to 10,000 feet in the air. At that height ...
|More News » |