Mars Microbes
Worry NASA &
World Health Officials
Discovery News Brief
NASA and world health officials are trying to determining how much of a biological threat, if any, microscopic organisms plucked from Mars could pose to Earth.
In its preparations for an unmanned mission to Mars ten years from now, NASA has turned to the surreal, otherworldly interior of Yellowstone National Park, where scientists believe that microbes inhabiting hot springs could provide a preview of what awaits the robotic lander on Mars, the Christian Science Monitor reports.
"There's no reason to put the Earth at risk due to our own biological ignorance. That's why we are exploring every possible safeguard," says John Rummel, NASA's newly appointed "planetary protection officer."
Thriving in conditions where other animals would perish, Yellowstone microbes live in a place with 300-degree temperature fluctuations, surrounded by corrosive acids that can eat through steel, and within toxic, oxygen-deprived niches that appear deceivingly sterile. Much like Mars, scientists say.
Some astral ecologists believe the primitive life forms on Earth may be distant relatives of Martian microbes swept together through the Milky Way on comets or asteroids billions of years ago and deposited on the neighboring infant planets.
And in many ways, Yellowstone's enigmatic concentration of thermal phenomena provides a glimpse at early life on Earth, according to the Christian Science Monitor.
"The premise behind our research is that if you want to better understand the organisms that may have existed, or still do exist, in the extreme conditions on Mars, a logical place to look for possible comparison is in the extreme environments on Earth," says microbiologist Fred Albert.
From their small laboratory at Montana Biotech, Albert and fellow microbiologist Joan Combie are assisting NASA in identifying potential planetary parallels.
Researchers say that many of Yellowstone's microbes living in hot springs occupy a different branch on the tree of life than the vast majority of other earthly organisms grouped in the domains eucarya (which includes humans, plants, and fungi) and bacteria.
The creatures in Yellowstone's hot springs have an amazing lineage that extends deep in the geologic record to the twilight of Earth's organic origins. Rather than deriving sustenance from other carbon life forms, some of them eat sulfur and silica.
The theory is that ancestors of these tiny creatures, fertilized by cosmic dust and changed little by evolution over the past 3.5 billion years, sprang to life in our ancient oceans and persist in Yellowstone's geothermal zones because the habitat is still relatively unaltered, the Christian Science Monitor reports.
It is possible that such life could have followed a similar path to Mars when it, too, had vast seas and active volcanism.
Allen says that the next Mars lander will collect samples mostly from rocks and areas of subsurface crust where evidence of ancient life may be clustered. So "there are real concerns, both scientific and legal, about bringing back rock and soil samples from far away places because of legitimate worries about transporting hidden microbes and bugs," Allen says.
In advance of that, Combie and Albert are refining the process of identifying microorganisms by isolating and, in some cases, arousing to life, microbes embedded in the limestone deposited by Yellowstone's hot springs to see how they can be manipulated.
"Using Yellowstone organisms ... NASA wants to know if they can sterilize whatever is brought back," Combie says. "What recent tests show is that some microbes are surprisingly resilient."
A few months ago, public-health officials bombarded organisms with high levels of gamma rays to see what it would take to destroy potentially hazardous microbes. It's the same sterilization techniques used to successfully kill threats such as the Ebola virus -- but the Yellowstone microbes were able to withstand the high dosage levels of radiation, leading researchers to view potential Martian life with greater reverence.

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