An experiment using simulated Martian conditions has found that perchlorates bathed in UV light would quickly kill many potential Martian bacteria:
The hope for Martian life took another blow today. As Ian Sample at The Guardian reports, a new study suggests that in the presence of ultraviolet light, perchlorates, a class of chemical compounds widespread on Mars' surface, turn deadly for bacteria.
The presence of perchlorates isn't new. Viking 1 and 2 spacecraft detected perchlorates when they landed on the Martian surface in 1976, Jeffrey Kluger reports for Time. Since then, other spacecraft have confirmed the presence of the compounds. The 2009 Phoenix lander found that perchlorates make up between 0.4 and 0.6 percent of the soil sample it collected.
While perchlorates, which are composed of chlorine and oxygen, are toxic to humans, microbes typically love the stuff. And researchers have been optimistic that their presence could support bacterial life on Mars. As Kluger reports, some bacteria on Earth use naturally occurring perchlorate as an energy source. The compound also lowers the melting point of water, which could improve the chance of liquid water existing on the Red Planet.
But the latest study, published in the journal Scientific Reports [open, DOI: 10.1038/s41598-017-04910-3] [DX], suggests that in the presence of ultraviolet light perchlorate is not so microbe-friendly. Mars has a thin atmosphere, which often leaves its surface bathed in UV rays. And when heated, chlorine-based molecules like perchlorates cause heavy damage to living cells, reports Sarah Fecht at Popular Science.
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NASA may have burned best proof of life on Mars by accident over 40 years ago
Viking landers sent to Mars in 1976 to search for organic matter reported finding nothing, a conclusion that shocked scientists at the time. New research published in the Journal of Geophysical Research Planets [DOI: 10.1029/2018JE005544] [DX], suggests the Vikings' main instrument might have actually discovered the organic matter but burned it while collecting soil samples, an article in New Scientist notes.
The primary instrument on the Viking landers, a gas chromatograph-mass spectrometer, used heat to try and find these molecules. That was big a mistake. Because of a now-known chemical in the soil perchlorate, the landers would have destroyed any organics in the process. NASA's Phoenix lander found perchlorate on Mars in 2008, Space.com notes.
Previously: Organic Matter Found on Mars
Related: NASA Discovers Evidence for Liquid Water on Mars
UV Radiation and Perchlorates Could be a Toxic Combination for Potential Mars Bacteria
Study Finds Evidence of More Organic Material on Ceres
Complex Organic Molecules Found on Enceladus
(Score: 0) by Anonymous Coward on Friday July 07 2017, @04:22AM (2 children)
You need to remember that life generally Finds A Way. The possibility that microbes managed to evolve that don't take damage from UV'ed perchlorates is possible. Heck, I remember reading an article where they found microbes in Antarctica (iirc) that evolved to live on arsenic which is typically pretty lethal as well.
(Score: 2) by JoeMerchant on Friday July 07 2017, @11:57AM
Let's not import any Clorox resistant microbes from Mars to my bathroom, shall we?
🌻🌻 [google.com]
(Score: 0) by Anonymous Coward on Friday July 07 2017, @12:07PM
If we're thinking about the same arsenic study, then it was retracted due to methodological flaws. Your point still stands, though.
(Score: 3, Insightful) by c0lo on Friday July 07 2017, @05:08AM (1 child)
So there won't be bacteria on the surface. Dig down and one may find good enough environ near the frozen water inside the soil.
Perchlorates and water and whatever minerals the bacteria can find around.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by kaszz on Friday July 07 2017, @07:35PM
Had the same idea too. Next question will be when a massive underground probing will take place. And maybe perchlorates are not present all the way down.
(Score: 2) by maxwell demon on Friday July 07 2017, @08:41AM (2 children)
FTFY
Oxygen is an extreme poison for anaerobic bacteria. A researcher from an anaerobic world might therefore conclude that the high concentration of oxygen on Earth suggests that life on Earth is highly improbable.
Tests with randomly selected bacteria from earth will reveal that extreme heat kills off bacteria. But not all of them: [wikipedia.org]
So the bacteria don't just survive those hot temperatures, they requre them.
If life evolved on Mars, it has evolved under Mars conditions. Therefore life forms on Mars will have evolved to live with perchlorates under UV. They possibly even need it to survive, just like we require the highly aggressive gas known as oxygen.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by bob_super on Friday July 07 2017, @06:56PM (1 child)
We should look for life on Venus, because the conditions there are a lot more dynamic and energetic than Mars.
It sure ain't gonna be life as we know it...
(Score: 2) by leftover on Friday July 07 2017, @07:07PM
Hmmm ... That sounds like an idea for a science-fiction B slasher movie. "Just one baby Venusian Dragonfly kicked all our asses, then it went home to tell Mom"
Bent, folded, spindled, and mutilated.
(Score: 0) by Anonymous Coward on Friday July 07 2017, @08:44AM (1 child)
"NASA Discovers New Space Age Antibiotic Big Pharma Doesn't Want You To Know About"
(Score: 0) by Anonymous Coward on Friday July 07 2017, @10:36AM
I'm pretty sure UV light strong enough to significantly enter your body would already kill you, even without the perchlorates.
(Score: 1) by DmT on Friday July 07 2017, @01:47PM (1 child)
We should test that idea!
Think about it - a planet sized laboratory! Extra resources in the future! All kinds of new knowledge for evolutionary science and biology.
All that needs to be done is to send various bacteria to Mars.
Leave a heritage for your children. Create aliens!
(Score: 0) by Anonymous Coward on Friday July 07 2017, @02:52PM
Let's not and say we did. - NASA