NASA’s Mars 2020 mission is geared to make breakthrough discoveries about past alien life on Mars. The US space agency’s Mars 2020 rover, which is based on the famous Curiosity robot, will drill into the surface of Mars to hunt down an alien fossil record. NASA’s goal is to drill into deposits of igneous Martian rock, which was deposited by ancient volcanic activity. A team of scientists from Sweden, however, have warned NASA needs to know exactly what it is looking for if it wants the mission to be a success.
Researchers at the Swedish Museum of Natural History have attempted to fix the problem by cataloguing the types of life commonly found in Earth’s igneous rock.
The “atlas of fossils in volcanic rock” of sorts, will guide NASA by telling the space agency exactly what to look for.
The conundrum was addressed this month (May) in the journal Frontiers in Earth Science.
Lead author Dr Magnus Ivarsson, said: “We propose a ‘volcanic microfossil atlas’ to help select target sites for missions seeing evidence of extraterrestrial life, such as the NASA Mars mission 2020 and ExoMars.
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“The atlas could also help us recognise what Mars microfossils might look like, by identifying biosignatures associated with different types of fossilised microbes.”
Mars is believed to have been a much hotter and wetter planet than it is today.
Almost all water on Mars exists today in the form of ice caps at the planet’s poles.
But deep ravines, winding canyons and snaking riverbeds provide ample evidence to suggest Mars once looked much more like Earth.
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In a wet environment like this, scientists believe microbial life would have been likely to develop in the same way it did on our home planet.
Dr Ivarsson and his team of researches studied the remains of ancient microbes embedded in rock samples from up to 0.6 miles (one km) beneath the deepest ocean floors.
These ancient microbes would have lived for up to 3.5 billion years ago.
Dr Ivarsson said: “The majority of microorganisms on Earth are believed to exits in the deep biosphere of the ocean and continental crust.
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“Yet we are just now beginning to explore – through deep drilling projects – the hidden biosphere.”
In a damp and dark environment where these critters exist, microbes and bacteria have adapted to thrive on the igneous rock surrounding them.
Colonies of microbes spread through minuscule cavities and tunnels in the rock, leaving behind evince of their presence.
Dr Ivarsson said: “Upon death, the microbial communities become fossilised on the walls of their rocky home.
“These microfossils can provide a history of microbial life in volcanic rock.”
A specialised fossil atlas will help NASA’s Mars exploration but also expand our understanding of microbial life here on Earth.
But in order to do that, scientists first need to collect more data on the appearance and chemical compositions of microbe fossils.
Dr Ivarsson said: “Our aim is to be able to use the oceanic crust microfossil record as a model system to guide Martian exploration.
“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.”