Venus Clouds May Support Photosynthesis
The surface of Venus is too extreme a survival environment. But life can hide much higher – in the clouds. A new study has shown that sunlight penetrating the thick cloud layer can support photosynthesis there, according to Astrobiology .
Researchers at California State Polytechnic University in Pomona have suggested that photosynthesis on Venus could take place around the clock. During the day it is fed by the Sun, and at night – by thermal or infrared energy emanating from the surface and atmosphere of the planet.
According to the theory of scientists, light energy penetrates both the upper and lower layers of the clouds. This provides great opportunities for microorganisms to inhabit.
The possibility of the origin of life on Venus has been the subject of long-standing scientific controversy. So, another study showed that the atmosphere of this planet is too dry to be habitable.
The authors of the new scientific work have questioned this thesis. They stated that Venus's clouds may be composed, in part, of neutralized forms of sulfuric acid, such as ammonium bisulfate. In this case, the percentage of water in them should be higher than it was thought.
The scientists emphasized that the acidity level and water activity in the Venusian clouds are in an “acceptable range” for the growth of terrestrial microorganisms. Solar and thermal radiation has those wavelengths of light that can be absorbed by known photosynthetic pigments.
Another important fact: moderate levels of ultraviolet radiation. Scientists have stated that Venus receives 80-90% less UV-A rays than Earth. UV-B and UV-C levels, which are considered the most harmful components of ultraviolet radiation, are also “substantially depleted”. The reason for this is still unknown.
Summarizing the above, scientists have concluded that the clouds of Venus are a promising target for future scientific missions to search for life. Earlier it was reported that a possible sign of life was found in the atmosphere of Venus – phosphine. But later the data was revised.