Different Scenarios for the Origin and the Subsequent Succession of a Hypothetical Microbial Community in the Cloud Layer of Venus.

The possible existence of a microbial community in the venusian clouds is one of the most intriguing hypotheses in modern astrobiology. Such a community must be characterized by a high survivability potential under severe environmental conditions, the most extreme of which are very low pH levels and water activity. Considering different scenarios for the origin of life and geological history of our planet, a few of these scenarios are discussed in the context of the origin of hypothetical microbial life within the venusian cloud layer. The existence of liquid water on the surface of ancient Venus is one of the key outstanding questions influencing this possibility. We link the inherent attributes of microbial life as we know it that favor the persistence of life in such an environment and review the possible scenarios of life's origin and its evolution under a strong greenhouse effect and loss of water on Venus. We also propose a roadmap and describe a novel methodological approach for astrobiological research in the framework of future missions to Venus with the intent to reveal whether life exists today on the planet.

Exploring the Kamchatka Geothermal Region in the Context of Life's Beginning.

This article is a brief review of research in the Kamchatka geothermal region initiated by David Deamer and the author in 1999. Results obtained over the last 20 years are described, including a seminal experiment in which biologically important organic compounds were dispersed in a hot spring to determine their fate. Other investigations include ionic and organic composition of hydrothermal water, the source of hydrothermally generated oil, and pressure-temperature oscillations in hydrothermal systems. The relation of these results to research on the origin of life is discussed.