Figure 1.

Major arguments for and against life on Venus, and some scientific speculations as to how some of the habitability challenges could be addressed by putative life in the Venusian cloud layer. In addition to resolving the question of the presence of organic compounds and phosphine, there are many other open questions regarding the Venusian environment, which would need to be resolved. Image shows cloud structure and presence of UV absorber (black streaks) as revealed by the Venus-Pioneer probe in 1979 (Credit: NASA).