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'Mars Could Have Supported Life': NASA Suggests Red Planet Was Habitable

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'Mars Could Have Supported Life': NASA Suggests Red Planet Was Habitable

Has NASA's Mars Curiosity Rover found something important on the surface of the Red Planet - perhaps even traces of life?

Each ice station will consist of layers of material and solid blocks of ice that students will drill into using equipment they designed and built.

These results also inform scientists' decisions as they work to find answers to questions concerning the possibility of life on Mars.

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The second paper investigates a problem that has been disturbing Mars scientists for several years: the abundance of methane in Mars' atmosphere.

Q: What organic molecules did you find, and how do they compare with anything that is found or produced on Earth? It's present in other places in our solar system that could host life, like Saturn and Jupiter's moons Enceladus, Europa and Titan.

"Are there signs of life on Mars?"

Ever since, scientists have ardently hunted for Mars's missing carbon-or at least an explanation for its absence. This could be a sign that there is a reservoir of methane somewhere under the surface that was generated by chemical reactions involving water or, possibly, by Martian microbes. That's particularly exciting since water ― so far as we know ― is also an essential ingredient for life.

It was to a great fanfare of publicity that researchers announced they had found evidence for past life on Mars in 1996.

The term "organic" means something different to a chemist than it does to a produce manager at a grocery store. This mudstone gradually formed billions of years ago from silt that accumulated at the bottom of the ancient lake. In fact, thiophenes are pretty simple molecules that are just a 5-sided carbon ring, but with a sulfur molecule replacing a carbon atom. In chemistry, almost all molecules containing both carbon and hydrogen are organic compounds. On Mars, where we only have a few molecules from a remote probe, this stuff is light years away from being conclusive.

The fluctuations in methane were observed over three Mars years (roughly six Earth years) by Curiosity's Sample Analysis at Mars (SAM) instruments.

"These clathrates lock the methane inside a water-ice crystal structure and are incredibly stable for millions of years until environmental conditions change and suddenly they can release that gas", says Duffy.

They may have also have been carried to Mars on an asteroid, for instance.

A set of geological results recently delivered courtesy of Curiosity's drill bit provides a deeper understanding of the organic chemistry of the 300-million-year-old mudstone in two separate parts of Gale crater. Tellingly, the methane levels appear to periodically spike in time with Martian seasons, being about three times higher in the sunny summertime than in the darker, colder winter. Curiosity reports that methane levels on Mars go up and down in a predictable cycle. "It's like having a problem with your auto", he says. But methane can also be produced by normal geologic processes.

Other scientists who did not take part in the research had mixed reviews on findings' significance in the search for life. Earth-based telescopes, spacecraft orbiting Mars and now Curiosity, have measured episodic sudden increases in the background methane content.

Scientists realized that they had to take a step back and try a more cautious, methodical approach.

He and his colleagues think the methane is coming from underground.

But the scientists can not say what the larger molecules were or how they formed. Such incremental progress is the whole point of NASA's Mars exploration program, Freissinet notes.

"It could have been from meteorites", she says.

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