Possibility of Life
Due to the harsh conditions on the surface, little of the planet has been explored; in addition to the fact that life as currently understood may not necessarily be the same in other parts of the universe, the extent of the tenacity of life on Earth itself has not yet been shown. Creatures known as extremophiles exist on Earth, preferring extreme habitats. Thermophiles and hyperthermophiles thrive at temperatures reaching above the boiling point of water, acidophiles thrive at a pH level of 3 or below, polyextremophiles can survive a varied number of extreme conditions, and many other types of extremophiles exist on Earth. However, the temperature of the surface of Venus (over 450°C), is far beyond the extremophile range, which extends only tens of degrees beyond 100°C.
However, life could also exist outside the extremophile range in the cloudtops, and in the same way that bacteria have been found living and reproducing in clouds on Earth, it has been proposed that life could exist in the same area on Venus. Microbes in the thick, cloudy atmosphere could be protected from solar radiation by the sulfur compounds in the air. The solar wind may provide a mechanism for the transfer of such microbiota from Venus to Earth.
The Venusian atmosphere has been found to be sufficiently out of equilibrium as to require further investigation. Analysis of data from the Venera, Pioneer and Magellan missions has found the chemicals hydrogen sulfide (H2S) and sulfur dioxide (SO2) together in the upper atmosphere, as well as carbonyl sulfide (OCS). The first two gases react with each other, implying that something must produce them. In addition, carbonyl sulfide is noteworthy for being exceptionally difficult to produce through inorganic means. Further, it is an often-overlooked fact that one of the early Venera probes detected large amounts of chlorine just below the Venusian cloud deck.
It has been proposed that microbes at this level could be soaking up ultraviolet light from the Sun as a source of energy, which could be a possible explanation for dark patches seen on UV images of the planet. Large, non-spherical cloud particles have also been detected in the cloud decks. Their composition is still unknown.
Read more about this topic: Atmosphere Of Venus
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