(ORDO NEWS) — Researchers at Monash University, the University of Queensland and the Australian National University have used the ANSTO Australian Synchrotron to study meteorites found on Earth that could be used in the future to find evidence of life on the planet Mars.
A collaborative team including Dr. Andrew Langendam found organic remains in the form of microfossils preserved in mineral veins within dense rock as a result of a study of meteorites found on the Nullarbor Plain in western South Australia.
“The site has been a recognized place to search for meteorites since the 1980s. The dark, iron-rich meteorites stand out against the white limestone and red soil of the plain,” said Dr. Langendam.
The study showed that various fossil microorganisms – diatoms, bacteria and fungi – were immured and preserved inside the veins of calcite and gypsum.
X-ray fluorescence microscopy at the Australian Synchrotron led by scientists Jessica Hamilton (then a PhD student at Monash) and David Paterson (both co-authors) confirmed that redox metals such as manganese and iron were mobilized in vein-filled cracks within the meteorite by environmental influences. environment or microorganisms.
“The location and amount of calcium, iron and manganese can be determined in the sample using ultra-sensitive techniques. It showed that manganese enrichment occurred at the marginal part of the calcite-gypsum veins,” said Dr. Hamilton.
The research team noted that meteorites may preserve a set of microfossils, organic biosignatures, and records of nutrient cycling in the arid conditions of Nullarbor.
Published in the journals Geochemica et Cosmochemica Acta and Frontiers in Microbiology, Dr. Alastair Tait of Monash University’s School of Earth, Atmosphere and Environment, said in a news post on Monash’s website: “This is an original discovery, and it is important because it shows us that microorganisms can interact with astromaterials in a way that is vital to their metabolism.”
Study co-author Prof Gordon Southam, from the School of Earth and Environmental Sciences at the University of Queensland, said: “This adds a new dimension to the search for life on Mars by targeting comparable meteorites on the red planet.”
“Essentially, they represent a time capsule of past biological activity, or, in the case of samples from the Nullarbor Plain, meteorites could harbor life,” Prof Southam said.
“They act like lifeboats for life on a hostile surface where there aren’t many bioavailable minerals,” Dr. Langendam said.
Mars has extreme conditions compared to Earth. The temperature on the desert surface of the Red Planet is about -62 degrees Celsius. Its atmosphere is very thin and is 96 percent carbon dioxide. The atmosphere of Mars is much less dense than that of Earth, with inhospitable low atmospheric pressure.
“Studying how meteorites on Earth are altered by weathering and microbial activity could help to know what chemical signatures to look for when studying the same meteorite material that fell on Mars that could have been weathered and potentially altered by some kind of life.
Consider chemistry Meteorites as a record of the environment and as a potential way to compare processes on Earth and other planets is a new idea and is really interesting,” said Dr. Hamilton.
Although the Martian landscape has been studied by a number of research vehicles, including the latest Perseverance Rover, not a single sample has yet been returned to Earth from the surface of the planet. Samples are analyzed by instruments on the surface.
The research team suggests that the samples returned from Mars will be used to build an overall picture of the volcanic and sedimentary history of Mars, which may have preserved past life.
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