In experiments that mimicked the harsh conditions of Mars, including X-ray radiation, scientists found that certain lichens not only survived, but also remained metabolically active. This breakthrough suggests that life as we know it, especially symbiotic organisms like lichens, may be more adaptable than previously thought, reshaping the perception of what types of life may exist beyond Earth.

For the first time, scientists have demonstrated that certain lichen species can survive in Mars-like conditions, including exposure to ionizing radiation, while remaining metabolically active.

The findings, published in the open-access journal IMA Fungi, suggest that lichens may be able to survive and function on the surface of Mars. This challenges long-held assumptions about Mars being uninhabitable and provides new insights into astrobiology and future space exploration.

Cetraria aculeata。 图片来源：Skubała 等人。

Lichens are not monolithic organisms, but are symbionts of fungi and algae or cyanobacteria. They are known for their extraordinary ability to withstand extreme environments, such as deserts and polar regions on Earth. In the study, the researchers found that the fungal components in the lichen still remained metabolically active under simulated Martian conditions, including darkness and levels of X-ray radiation equivalent to a year of intense solar activity on Mars.

The study tested two types of lichens – Diploschistes muscarum and Cetraria aculeata – which were selected for their very different properties. They were all exposed for five hours in a Mars simulation chamber that simulated the Martian atmosphere, pressure, temperature changes, and radiation.

Experimental setup for the vacuum chamber and its ancillary facilities, including a metal grating covered with lichen, a cooling table, temperature, pressure and humidity sensors, an X-ray lamp with a controller, a carbon dioxide valve with a gas cylinder, a vacuum chamber controller, a pressure controller, a cooling table controller and a computer. Image source: Skubała et al.

The results of the study show that despite the high doses of X-ray radiation produced by solar flares and high-energy particles reaching the surface of Mars, lichens, especially D. It is still possible for Muscurum to survive on Mars. These results challenge the hypothesis that ionizing radiation is an insurmountable obstacle to life on Mars and lay the groundwork for further research into the possibility of survival of extraterrestrial microbes and symbionts.

Kaja Skubała, first author of the paper, said: "Our study demonstrates for the first time that the metabolism of lichen symbiotic fungal partners remains active in an environment similar to the surface of Mars. We found that Diploschistes muscorum is able to carry out metabolic processes and effectively activate defense mechanisms. ”

These findings expand our understanding of biological processes in mimicking Martian conditions and reveal how aqueous organisms respond to ionizing radiation, one of the most critical challenges to the survival and habitability of Mars. Ultimately, this research deepens our understanding of lichen adaptability and its potential for colonization in extraterrestrial environments.

Further long-term studies have been proposed to investigate the effects of chronic radiation exposure on lichens, as well as experiments to assess their survival in a real Martian environment.

编译自/ScitechDaily