The Case (or Not) for Life in the Venusian Clouds

Abstract

The possible detection of the biomarker of phosphine as reported by Greaves et al. in the Venusian atmosphere stirred much excitement in the astrobiology community. While many in the community are adamant that the environmental conditions in the Venusian atmosphere are too extreme for life to exist, others point to the claimed detection of a convincing biomarker, the conjecture that early Venus was doubtlessly habitable, and any Venusian life might have adapted by natural selection to the harsh conditions in the Venusian clouds after the surface became uninhabitable. Here, I first briefly characterize the environmental conditions in the lower Venusian atmosphere and outline what challenges a biosphere would face to thrive there, and how some of these obstacles for life could possibly have been overcome. Then, I discuss the significance of the possible detection of phosphine and what it means (and does not mean) and provide an assessment on whether life may exist in the temperate cloud layer of the Venusian atmosphere or not.

Marine Science Can Contribute to the Search for Extra-Terrestrial Life

“…“Atmosphere” includes the investigation of whether gas spectral characteristics of exo-planets could be interpreted as bio-signatures, given what we know of geological traces left by the evolution of life on Earth. Life could be detected according to astronomical biosignatures such as specific proportions of atmosphere gases such as “oxygen” and reduced gases such as molecular hydrogen, methane, carbon monoxide, and phosphine [ 102 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 ].…”

Venus, Phosphine and the Possibility of Life

“…Speculation about the possibility of life in the clouds of Venus dates back to the very earliest days of our understanding of the true conditions on the planet [27] and continues to the present day (eg. [28,29]).…”

Simulating asteroid impacts and meteor events by high-power lasers: from the laboratory to spaceborne missions

“…Laser experiments will be crucial for the future identification of markers of impacts, such as in the case of the Shoemaker-Levy comet impact on Jupiter (Zahnle et al, 1995), where S 2 , CS 2 , OCS, NH 3 , HCN, H 2 O, and CO have been observed (Zahnle et al, 1995). Recent studies are also associated the tentative detection of PH 3 in the atmosphere of Venus (Bains et al, 2021;Schulze-Makuch, 2021;Truong and Lunine, 2021;Bains et al, 2022) to a stochastic atmospheric corrosion of a single giant impactor or to a random elevation in the impact flux (Omran et al, 2021). A possible future milestone in astronomy is to detect very large meteors and impacts in exoplanetary atmospheres.…”