Is NASA trying on the flawed rocks for clues to Martian life…
In 2020, NASA and European-Russian missions will search for proof of previous life on Mars. However whereas volcanic, igneous rock predominates on the Purple Planet, just about the complete Earth fossil report comes from sedimentary rocks.
Addressing the issue in Frontiers in Earth Science, Swedish scientists have begun compiling proof of fossilized microbes in underexplored igneous rock environments on Earth, to assist information the place to seek for a Martian fossil report — and what to search for.
“We propose a ‘volcanic microfossil atlas’ to help select target sites for missions seeking evidence of extraterrestrial life, such as the NASA Mars mission 2020 and ExoMars,” says lead writer Dr. Magnus Ivarsson. “The atlas could also help us recognize what Mars microfossils might look like, by identifying biosignatures associated with different types of fossilized microbes.”
Earth’s deep biosphere
Ivarsson and colleagues examine life buried in deep rock and deep time: fossilized stays of mysterious microbes, which have lived as much as a kilometer beneath the deepest ocean flooring for so long as 3.5 billion years.
“The majority of the microorganisms on Earth are believed to exist in the deep biosphere of the ocean and continental crust,” reveals Ivarsson. “Yet we are just now beginning to explore — through deep drilling projects — this hidden biosphere.”
In a watery world that by no means sees daylight, micro organism, fungi and different microbes have tailored to feed on the igneous rock that surrounds them — and even on one another. They unfold via micro-fractures and cavities, forming advanced and prolonged communities.
“Upon death, the microbial communities become fossilized on the walls of their rocky home. These microfossils can provide a history of microbial life in volcanic rock.”
A volcanic microfossil atlas
Crucially, Earth’s oceanic crust is geochemically similar to the volcanic rocks that dominate the Martian panorama.
“Our aim is to be able to use the oceanic crust microfossil record as a model system to guide Martian exploration,” Ivarsson explains. “Our review of existing knowledge is an important first step, but a more comprehensive understanding of the deep life is needed to show where and what to search for.”
To attain this, says Ivarsson, we have to accumulate extra information on microfossil look and site — but additionally, on their chemical composition.
“These fossils typically protect immense morphological element. For instance, we are able to distinguish broad lessons of fungi via the looks of spores, fruiting our bodies, mycelia and different development states — or of micro organism, via the presence of cauliflower-like formations, generations of biofilms preserved as laminated sheets, and different attribute group buildings.
“However evaluation of lipids and carbon isotopes in microfossils will make it attainable to discriminate extra exact teams based mostly on their metabolism.
“Altogether this information will help to identify which types of microorganism are most likely to have been preserved on Mars, and which geochemical conditions most favour fossilization.”
A fossil report on Mars
The microfossil atlas would due to this fact additionally assist to find out which samples needs to be focused for return to Earth, given the restricted payload of the Mars missions.
“Each NASA’s Mars 2020 and the ExoMars missions are able to detecting bigger fossilized buildings from volcanic rocks, corresponding to mm-sized mineralized fungal mycelia, or bigger microstromatolites in open vesicles.
“ExoMars’s 8 micrometer/pixel cameras have a greater chance of identifying small features and individual hyphae in situ on Mars. However, the NASA mission has the possibility of collecting samples for later investigation on Earth, and its 15 micrometer/px cameras may therefore be sufficient select samples with a high probability of containing biosignatures. These complimentary strategies increase the overall chance of detecting evidence of past life on Mars, if it exists,” concludes Ivarsson.
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