S07 → N400
The Spike of Fascinating & Unexpected
SPIKE 66
→ LICHEN.
© 1. jim_mcculloch (Flick) / 2. NCYT Amazings — Xanthoria parietina / 3. Dominique Delfino — Luminous tableau of an orange crustose lichen photographed on the stone of an old staircase / 4. Hector Ruiz — British soldiers lichen (Cladonia cristatella), so named for its red fruiting bodies / 5. Stephen Sharnoff — Rhizocarpon badioatrum / 6. Umberto Salvagnin — Xanthoria parietina / 7. E. Florence — Rhizocarpon petraeum / 8. Marianne Perdomo — Xanthoria parietina / 9. L. Sancho/ESA — Rhizocarpon geographicum.
-100
-400
Lichens play a vital role in ecosystems by contributing to soil formation, nitrogen fixation, and nutrient cycling. It can colonise barren or inhospitable surfaces, such as rocks, tree bark, and soil, helping to stabilise substrates and create habitats for other organisms. They are also sensitive to environmental changes and pollution, making them valuable indicators of air quality and ecological health. Certain species of lichen are indeed used as bioindicators to assess environmental pollution levels, notably air pollution from sulfur dioxide and heavy metals.
Lichens have also been used by humans for various purposes throughout history. In traditional medicine, certain species of lichen were believed to have medicinal properties and were used to treat ailments such as digestive issues, respiratory problems, and skin conditions. Additionally, lichen has been used as a source of dye for textiles, producing colours ranging from red and orange to yellow and brown. In some cultures, lichens were also used as a food source during times of scarcity, although not all species are edible, and some may be toxic.
In 2005, ESA conducted an experiment where they exposed lichen specimens to the harsh conditions of space aboard the FOTON-M2 mission. This experiment was aimed at establishing, for the first time, the survival capability of lichens exposed to space conditions. In particular, the damaging effect of various wavelengths of extraterrestrial solar UV radiation was studied. The lichens used were the bipolar species Rhizocarpon geographicum and Xanthoria elegans, which were collected above 2000 m in the mountains of central Spain and as endolithic communities inhabiting granites in the Antarctic Dry Valleys. Lichens were exposed to space in the BIOPAN-5 facility of the European Space Agency; BIOPAN-5 is located on the outer shell of the Earth-orbiting FOTON-M2 Russian satellite. The lichen samples were launched from Baikonur by a Soyuz rocket on May 31, 2005, and were returned to Earth after 16 days in space, at which time they were tested for survival. All exposed lichens, regardless of the optical filters used, showed nearly the same photosynthetic activity after the flight as measured before the flight. Likewise, the multimicroscopy approach revealed no detectable ultrastructural changes in most of the algal and fungal cells of the lichen thalli, though a greater proportion of cells in the flight samples had compromised membranes. These findings indicate that most lichenised fungal and algal cells can survive in space after full exposure to massive UV and cosmic radiation, conditions proven to be lethal to bacteria and other microorganisms. The lichen upper cortex seems to provide adequate protection against solar radiation. Moreover, after extreme dehydration induced by high vacuum, the lichens proved to be able to recover, in full, their metabolic activity within 24 hours (Sancho et al., 2007).
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→ Sourced from: SYSTEM 04 (Poutchka Patrol)
→ Stored online: N400 Spikes Repository
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→ Search log: Google images / ESA
→ Reference: Sancho, L. G., De La Torre, R., Horneck, G., Ascaso, C., De Los Rios, A., Pintado, A., Wierzchos, J., & Schuster, M. (2007). Lichens Survive in Space: Results from the 2005 LICHENS Experiment. Astrobiology, 7(3), 443–454. https://doi.org/10.1089/ast.2006.0046
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