DCU researchers developing system that could prove if there is life on Mars
In the context of the upcoming missions to Mars, and the plan to bring samples of rock back to Earth it will be crucial to have a standardised, internationally agreed, well tested method for analysing whether ancient micro structures were produced by life forms or not.
DCU professor Seán Jordan, a recent ERC grant recipient, said:
“The problem with the estimates of the earliest life forms is that the features created by these early organisms, which left physical imprints in these ancient rocks, could, I believe, have been created by some other process that does not involve any life forms. The investigations we are undertaking at DCU can provide a much better method for answering this important question with greater certainty.”
Dr Jordan's research, recently published in Communications Earth and Environment, presents a direct link between the origin of life and microfossil interpretation. The team has shown that lipid vesicles, representative of the first stages of cell membrane development at the emergence of life, are capable of satisfying morphology criteria applied to traces of life from the early Earth, and the development of advanced statistical approaches is required to pinpoint potential differences which may enable us to distinguish between biogenic and abiogenic structures. It has been suggested that the preserved remnants of prebiotic chemistry could potentially satisfy many of the widely accepted biogenicity criteria currently applied to possible microfossils.
The current paper is just the beginning: the work represents a miniscule fragment of all possible prebiotic biomorphs which could be observed in geological samples from the early Earth and potentially elsewhere in the Solar System. These biomorphs could also inform on potential fossilised signatures of life’s emergence which could be observed in either terrestrial or extra-terrestrial samples – protobiosignatures. A substantial effort is required to determine the full range of possible prebiotic biomorphs which could affect our interpretation of the earliest rock record including advanced physical, chemical, and statistical analytical approaches.
Nasa is planning a Mars sample return mission in the 2030s. This will involve returning samples of rock and dust to the Earth for analysis. At this point, it will be critical that science has a tried and trusted method for identifying the early signs of life in ancient samples.
“We urgently need to develop a sure-fire scientific method to identify the earliest signs of life in ancient rocks, and that was the focus of this new research,” Dr Jordan said. “Right now, when we are looking at tiny microstructures in ancient rocks, we can’t be sure whether they were made by early living things, or some non-living process.
“This non-living process may even be a sign of the chemical structures that lead to the origin of life.
“I’m developing methods to allow us to investigate exactly that. This is important because it will enable scientists to identify the first signs of life on Earth and possibly on other planets.”