Venus' Spectral Signatures and the Potential for Life in the Clouds

• DOI: 10.1089/ast.2017.1783
• Publication Date: 2018-03-30T14:27:30Z
• Authors: Sanjay S. Limaye; Rakesh Mogul; David J. Smith; Arif H. Ansari; Grzegorz P. Słowik; Parag Vaishampayan
• Keywords: Atmosphere of Venus; Albedo (alchemy)

The lower cloud layer of Venus (47.5-50.5 km) is an exceptional target for exploration due to the favorable conditions microbial life, including moderate temperatures and pressures (∼60°C 1 atm), presence micron-sized sulfuric acid aerosols. Nearly a century after ultraviolet (UV) contrasts Venus' were discovered with Earth-based photographs, substances mechanisms responsible changes in albedo are still unknown. While current models include sulfur dioxide iron chloride as UV absorbers, temporal spatial contrasts, albedo, between 330 500 nm, remain be fully explained. Within this context, we present discussion regarding potential microorganisms survive clouds contribute observed bulk spectra. In article, provide overview relevant observations, compare spectral physical properties terrestrial biological materials, review iron- sulfur-centered metabolism clouds, discuss conceivable transport from surface toward more habitable zone identify experiments that could measure habitability analogues. Together, our lines reasoning suggest particles contain sufficient mass balance harbor microorganisms, water, solutes, potentially biomass detected by optical methods. As such, comparisons presented article warrant further investigations into prospect biosignatures clouds.