Tuesday, March 31, 2015

NASA’s Curiosity rover finds fresh signs of ingredients for life on Mars

Mars's life-friendly past just got friendlier. Using samples previously collected by the NASA rover Curiosity, scientists have discovered evidence of nitrates in Martian rock: nitrogen compounds that on Earth are a crucial source of nutrients for living things.

The findings, published in the journal Proceedings of the National Academy of Sciences, lend further support to the idea that the Red Planet, now barren and dry, could once have hosted habitable environments.

Although planetary scientists have been on the hunt for organic carbon – the type of carbon-containing molecules that could be used and produced by living things – nitrogen also plays an essential role in life as we know it, said lead author Jennifer Stern, a planetary geochemist at NASA Goddard Space Flight Center in Greenbelt, Md.

For example, nitrogen is a key component of nucleobases that make up RNA and DNA, and of amino acids, the building blocks of proteins.



“People want to follow the carbon, but in many ways nitrogen is just as important a nutrient for life,” said Stern, a science team member for the Mars Science Laboratory mission, as Curiosity’s mission is formally known. “Life runs on nitrogen as much as it runs on carbon.”

So the scientists examined data from three samples processed by the Sample Analysis at Mars, or SAM, instrument, which is part of a formidable laboratory in Curiosity’s belly. They looked at samples pulled from three spots near its landing site: aeolian deposits from Rocknest and mudstone deposits from John Klein and Cumberland.

These sites were all visited during a detour from Curiosity’s main mission, which was to drive to Mt. Sharp, the 3-mile-high mound in the middle of Gale Crater whose clay-rich layers looked like an ideal spot to search for signs of past habitable environments. Going off course was a risk, but it paid off; the John Klein and Cumberland mudstones have previously turned up a smorgasbord of chemicals and water-altered minerals that would have made it a potentially prime place for life, if it ever existed on the Red Planet. Now, this fresh analysis of the nitrogen compounds in these rocks further strengthens that idea.

The rock samples were cooked in SAM’s oven and the resulting gases were analyzed. The researchers found a significant amount of nitric oxide, a compound that, before it was cooked, probably came from nitrates, Stern said.


“What we’re detecting is nitric oxide, but we know from lab experiments that when we heat up nitrates, they break down in a predictable way,” Stern said. “And that’s why we think these are nitrates.”

The researchers had to carefully subtract out the amount of contamination that would be coming from the rover itself, to make sure they were not getting a false signal.

When they finished, they were still left with a significant amount of nitrogen – enough to account for 110 to 300 parts per million of nitrate in the Rocknest sample, 70 to 260 parts per million in John Klein and 330 to 1,100 parts per million in Cumberland. That’s comparable to the amount of nitrates you’d get in extremely dry places on Earth, such as the Atacama Desert in South America.

Nitrates are important molecules because it's easier for living things to access nitrogen and put it to work, Stern said. Nitrogen in the atmosphere is typically made of two nitrogen molecules that are triple-bonded to each other, making it a tough molecule to cut apart. Nitrates consist of a nitrogen linked to three oxygen atoms with only single or double bonds, and are much easier to disassemble.

Most nitrates on Earth are produced by living things, Stern said. But in the case of Mars, the team believes the nitrates were created during a “thermal shock,” such as a lightning strike or an asteroid impact.

Among the next steps, she says, is to see whether whatever process that generated these nitrates is still happening on Mars.

“We’re going to try to understand whether this process is still happening today at all,” Stern said, “or whether this all happened in the past in a different Mars, in a different climate regime, in a different atmosphere.”

http://www.latimes.com/

3 comments:

  1. If this is real that finding live on Mars. That will be a great news for us. According to the environmental analysis, we can see that earth can no longer bare the pollution and human activities.

    ReplyDelete
  2. (Coach Outlet Clearance Sale) mug of coffee. Bah. Dah. Here an appearance that work well almost anyplace that your chosen coat isn fundamental: Standard formula to take java aside[Your family] (Coach Outlet Store Online) Lighthearted typical model normally pair a dingy that will set of two tight pants or skirts getting a white color narrow work with option downward or impartial various tee, (New Yeezys 2020) Set of cheap main whitened footwear and your relax and monitor or pendant, Statements Livingston. Most of the time tips friends and (Ray Ban New Wayfarer Polarized) neighbors to retract the masturbator fleshlight sleeves with all the control straight along also cuff they for (Yeezy Boost 350 Cheap) a doubly easy find. Why not consider athleisure, The latest comfortable agreed to procedure for off from some time shower? Pops up to, Ever again, The particular area you have (Michael Kors Outlet) in addition to wheyou like tor match in unfit or not, Leat tells of the extremely enjoyable occurrence.

    ReplyDelete
  3. "It is occurring in just about all countries, apart from the lowest income countries," says Professor Boyd Swinburn, with the World Health Organizations Collaborating Centre for Obesity Prevention in Melbourne, Australia. "There is quite a lot of evidence now coming out that this is being driven by changes in the food system," he says. "The food supply: increasingly processed, available, affordable and highly promoted tasty food.".

    Why does sleep deprivation make us snappish The emotional part of the brain, the amygdala, is much more active Coach Outlet Online when deprived of sleep, finds a study Ray Ban Outlet by Matthew Coach Outlet Clearance Sale P. Walker, PhD, Cheap Michael Kors Handbags director MK Outlet Online of Best Yeezys the Sleep and Neuroimaging Laboratory at the University of Nike Air Force 1 Cheap Outlet California, Berkeley. Normally, the more rational prefrontal cortex would put everything into context but when the brain is Jordan Shoes For Sale sleep addled, this relationship breaks down..

    ReplyDelete