There may be life on the exoplanets Proxima Centauri b and TRAPPIST-1 e
A study by European scientists showed that disputes Aspergillus niger will be able to survive on these exoplanets.
As you know, Proxima Centauri is the closest star to the solar system and is located only 4.2 light years from Earth. Small and cool M-type red dwarfs, such as Proxima Centauri, make up about 70 percent of the stars in the Milky Way.
How habitable are M-dwarf exoplanets? To answer this question, the researchers used modeling of surface conditions on the planet and studied the role of melanins in the survival of Aspergillus niger spores under the influence of exoplanet radiation.
Confirming the habitability of exoplanets remains a challenge due to the large distances separating Earth from other stars. Therefore, using knowledge of biology and astrophysics, scientists studied the habitability of M-dwarf exoplanets by simulating their surface temperatures and doses of flare ultraviolet and X-ray radiation, using the Martian atmosphere as a model for atmospheric protection.
As a result of the analysis of models of the star systems Proxima Centauri and TRAPPIST-1, it turned out that the exoplanets Proxima b and TRAPPIST-1 e are likely to have temperatures compatible with liquid water on the surface, as well as a tolerable radiation environment.
The simulation results were used as the basis for microbiological experiments to evaluate the survival of spores of the melanin-rich fungus Aspergillus niger to exoplanet-like radiation (UV-C and X-rays). The results showed that A. niger spores can survive superflares on M-dwarf planets when they are protected by the Martian atmosphere or a thin layer of soil or water.
Melanin-deficient spores suspended in melanin-rich solution showed higher survival and germination efficiency compared to melanin-free solutions. Overall, the models developed in this work provide a basis for microbiological studies in habitability studies.
The work also showed the importance of multifunctional molecules such as melaninsin radiation protection beyond the Earth.
Melanins are widely distributed in plant and animal tissues, as well as in protozoa. They determine the color of skin and hair, for example, the colors of horses, the color of bird feathers, fish scales, and insect cuticles. Melanins absorb ultraviolet rays and thereby protect the tissues of the deep layers of the skin from radiation damage, protect the genetic information stored in the nuclei of cells, and prevent the malignant degeneration of cells under the influence of ultraviolet radiation.
Author: Alexander Tarlakovsky (blog tay-ceti.space)
Research Article: How habitable are M-dwarf Exoplanets? Modeling surface conditions and exploring the role of melanins in the survival of Aspergillus niger spores under exoplanet-like radiation (How habitable are M-dwarf exoplanets? Modeling surface conditions and studying the role of melanins in spore survival Aspergillus niger under the influence of exoplanet radiation). 03/06/2024.
Afonso Mota (1, 2), Stella Koch (1), Daniel Matthiae (3), Nuno Santos (2, 4) and Marta Cortesão (1)
1. Aerospace Microbiology Research Group, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
2. Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
3. Biophysics Research Group, Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
4. Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
