Living Earth microbes populate virtually every corner of the world, including extremely harsh environmental conditions like the hot springs of Yellowstone, the hydrothermal wells of the deep ocean, and the toxic mud of polluted areas. Earthly bacteria were also identified as living, as high in our atmosphere as 25 miles (40 km). Neighboring Venus is a hostile world. The heat trapped by the dense atmosphere makes it hot enough on the surface to melt lead. But a series of space probes ̵
Article was published online on March 30, 2018 in the journal Astrobiology The biochemist Rakesh Mogul of California State Polytechnic University Pomona is co-author of the new paper. In a statement, he noted that the cloudy, highly reflective, acidic atmosphere of Venus consists mainly of carbon dioxide and water droplets containing sulfuric acid. He commented:
On Earth, we know that life can thrive in very acidic conditions, feed on carbon dioxide and produce sulfuric acid.
The planetarologist Sanjay Limaye of the University of Wisconsin headed the new study. He is not unfamiliar with the idea of a possible microbial life in the clouds of Venus, possibly in the hitherto unexplained dark streaks or specks in the clouds, which are known to absorb ultraviolet light. Limaye said in Astrobiology Magazine in January 2017:
These are questions that have not yet been fully explored, and I scream as loudly as I can tell that we need to research them.
In this latest study, scientists research them as best they can without going to Venus.
Limaye pointed out that questions about the possible habitability of Venus clouds were first raised in 1967 by the well-known biophysicist Harold Morowitz and the famous astronomer Carl Sagan. But, said Limaye, his latest study was inspired in part by:
… a chance meeting with paper co-author Grzegorz Slowik of the Polish University Zielona Góra. Slowik drew his attention to bacteria on Earth with light-absorbing properties that resemble those of unrecognized particles that make up inexplicable dark spots in the clouds of Venus. Spectroscopic observations, especially in the ultraviolet range, show that the dark spots consist of concentrated sulfuric acid and other unknown light-absorbing particles.
These dark patches were a mystery as they had been observed by ground-based telescopes for almost a century … They were more closely examined by subsequent probes to the planet.
The particles that make up the dark spots have almost the same dimensions as some bacteria on Earth, although the instruments that have so far sampled the Venus atmosphere are incapable of distinguishing between materials of an organic or inorganic nature. These scientists believe that the stains resemble the algal blooms routinely found in the lakes and oceans of the Earth. Limaye commented:
Venus had enough time to develop the life of himself.
Using computer modeling to suggest that Venus once had a habitable climate with liquid water on its surface for 2 billion years, he said:
This is much longer than one would expect on Mars.
The Wisconsin scientist and his colleagues remain confident that the question of life in the Venusian clouds may remain open. They point to ongoing discussions about a possible participation of NASA in the Russian mission Roscosmos Venera-D, which is planned for the late 2020s. Current plans for Venera-D may include an orbiter, a lander and a NASA sponsored surface station and a moving aerial platform.