Laser-powered devices tested on Earth could help detect microbial fossils on Mars

The first life on Earth was formed 4 billion years ago as microorganisms that live in pools and oceans. What if the same thing happened on Mars? If so, how would we prove it? Scientists who want to identify evidence of fossils of life in ancient Martian microorganisms now find a way to test their hypothesis and detect microorganism fossils in gypsum samples similar to Martian sulfate rocks It proves that it can be done.

“Our findings provide a methodological framework for detecting sulfate mineral biosignatures and could lead to future Mars exploration missions,” said Dr. Youcef Sellam. Students at the Institute of Physics at the University of Bern, and the first author of articles in Frontiers of Astronomy and Space Sciences.

“The laser ablation ionization mass spectrometer, a spaceflight prototype instrument, can effectively detect sulfate mineral biosignatures. This technology can be integrated into future Mars Rovers or Landers for In-Situ analysis.”

Water, water everywhere

Billions of years ago, Mars water was depleted. Gypsum and other sulfates form when the pool evaporates, leaving behind minerals precipitated from the water, potentially fossilizing the remaining organic life. This means that if microorganisms such as bacteria lived there, traces of their existence could be preserved as fossils.

“Plaster has been widely detected on the surface of Mars and is known for its extraordinary fossilization potential,” Serum explained. “It forms quickly and traps microorganisms before decomposition occurs, conserving biological structures and chemical biosignatures.”

However, to identify these microorganisms, similar fossils can be identified in places where such microorganisms are known to exist, such as the Mediterranean gypsum layer that occurred during the Messinian salinity crisis. You need to prove it.

“When the Mediterranean Sea was blocked from the Atlantic, there was a salinity crisis for Messenger,” Serum said. “This results in rapid evaporation, making the ocean sensitive and deposits thick layers of evaporated rocks, including gypsum. These deposits provide excellent terrestrial analogues for sulfate deposition mine deposition deposits. I’ll do that.”

Scientists have chosen equipment that can be used in spaceflight: miniature laser-powered mass spectrometers can analyze in detail the chemical composition of fine samples, like micrometers.

They sampled gypsum from the Sidi Boutbal quarry in Algeria and analyzed it using a mass spectrometer and optical microscope. This was induced by criteria that helped to distinguish between potential microbial fossils and natural rock formations.

These can be affected by irregular, supple, potentially hollow morphology, and the presence of chemical elements necessary for life, carbonaceous materials, minerals such as clay and dolomite, which are likely to be affected by the presence of bacteria. .

Living on Mars?

Scientists have identified long, twisted fossil filaments in Algerian gypsum, previously interpreted as benthic algae or cyanobacteria, and are now considered to be sulfur-oxidizing bacteria like begggiatoa. These were embedded in gypsum and surrounded by dolomite, clay minerals and pyrite.

The presence of these minerals indicates the presence of organic life, as the nucleus-free cells-supply elements of the supply elements that clays need to form. It also promotes dolomite formation in acidic environments like Mars, increasing the surrounding alkalinity, and concentrates ions in cell envelopes.

For dolomite to form in gypsum without the presence of organic matter, it requires dehydration of the gypsum and high temperatures and pressures that are not consistent with Mars’ environmental knowledge.

If mass spectrometers identify the presence of clay and dolomite in Mars gypsum in addition to other biosignatures, this could be a critical signal for fossilized life.

“Our findings strongly support the biogenetic nature of plaster fossil filaments, but distinguishing between true biosignatures and non-biotic mineral layers is a challenge,” Ceram warns.

“Additional independent detection methods will improve confidence in life detection. Additionally, Mars has unique environmental conditions that can affect biosignature storage over a geological period. Further, Research is needed.”

“This study was the first astrobiology study to involve Algeria and the first to use Algerian terrestrial analogues on Mars,” Serum said. “As an Algerian researcher, I am extremely proud to introduce my country to the field of planetary science.

“This work is also dedicated to the memory of my father, who was a great source of strength and encouragement. Losing him in this study was one of the most difficult moments in my life.”