A study published in Astrobiology on November 13 reveals the challenges posed by cosmic radiation in preserving possible traces of life on Mars. The researchers simulated the effects of cosmic rays on lipids, important molecular structures found in cell membranes. The findings indicate that lipids are rapidly degraded when exposed to radiation, especially under salt-rich conditions. This has raised concerns about the preservation of biosignatures in areas on Mars once thought to be most likely to harbor life.
As reported, Anais Roussel, an astronomer at Georgetown University, highlighted the issue of a salt-rich atmosphere on Mars. They choose salt-rich environments, but they can be most harmful under radiation, Roussel told Space.com. These findings raise concerns about whether the surface of Mars, which is constantly exposed to cosmic radiation due to the absence of an atmospheric shield, could preserve molecular evidence of ancient life.
Salt and radiation: a double threat
Research indicated that lipids exposed to simulated cosmic rays deteriorated significantly within three million years, with more than half the molecules disintegrating into smaller fragments. By comparison, some Martian rocks, such as those from Gale Crater, have been exposed to radiation for about 80 million years. The addition of salt to the samples accelerated the dissolution, which revealed a chemical reaction between the radiation-induced compounds and organic molecules. The exact mechanisms driving this rapid decline remain under investigation.
Deep investigation may provide answers
Reportedly, while existing NASA rovers, including Curiosity and Perseverance, can only drill to shallow depths, the European Space Agency’s Rosalind Franklin rover, scheduled to launch in 2029, will be able to drill down to two meters. Designed to drill. This capability can bypass most surfaces affected by radiation. In statements to Space.com, Roussel advocated missions targeting Martian caves or lava tubes, which may provide pristine conditions. He said that it will be very challenging from engineering point of view, but this increases hope.
The study emphasizes the importance of revisiting exploration strategies to take into account the limitations posed by radiation and environmental factors on Mars.
