Times	*Authors (Denotes Presenter)**	Abstract Title and Summary
2:00 p.m.	Borisov K. Ocampo A.	Welcome to the Workshop Recording
2:15 p.m.	Amato P. *	Terrestrial Hints for Prospecting Microbial Life in Venus Clouds [#4031] Presentation Recording On Earth, clouds are thought to be particular environments in the atmosphere, providing water, nutrients, and protection against UV radiation to microbial cells. Although the conditions are much more favorable than on Venus, investigating biological material scattered in clouds or in the air, its viability and metabolic activity are already highly challenging. Methods and approaches potentially applicable to extraterrestrial environments have been developed.
2:45 p.m.	Kotsyurbenko O. R. *	Astrobiology of Venus: Basic Insights and Prospects (Application to Venera-D Mission) [#4005] Presentation Recording Important issues that require discussion in preparation for the Venus-D space mission are the creation of an appropriate concept of the habitability of the Venus cloud layer and recommendations for the astrobiological research program for this ecosystem. New ideas that have been outlined in recent publications on Venus are critically revised and promising microbiological research is proposed.
3:00 p.m.	Schulze-Makuch D. *	Habitability Challenges in the Venusian Clouds [#4016] Presentation Recording The Venusian cloud environment poses stark challenges to habitability, especially in regard to water activity and acidity. Could those challenges be overcome by life? Here I introduce several suggestions on what observations and knowledge we need to gain, both theoretically and stemming from laboratory investigations, to achieve further insights on the specifics of these challenges in the Venusian atmosphere and how these could possibly be overcome.
3:15 p.m.	Grinspoon D. H. *	Gaia on Venus: Planetary-Scale Considerations of Habitability [#4047] Presentation Recording I discuss the “Living Worlds Hypothesis” of planetary habitability, which emphasizes planetary scale properties such as level of geological activity and cycling of volatiles between interior, surface, and atmosphere over specific localized conditions, and how this alternative view may illuminate the question of habitability of the Venus clouds. Investigations by the upcoming missions which bear on this topic will be addressed.
3:30 p.m.	Gentry D. M. * Iraci L. Cassell A. Mattioda A. Brecht A. Simon K. Sobron P. Davila A.	Aerobiospheres and Planetary Habitability: Considerations from Earth to Venus and Beyond [#4045] Presentation Recording Clouds are likely to be found on rocky worlds with water, but should they be considered a potential habitat? Lessons from Earth’s airborne microbiota emphasize the importance of local microenvironments, the sparseness and heterogeneity of viable and active life, and the necessity for coordination between physical modeling and biological investigation. Exploration of Venus cloud layers would significantly benefit from architectures allowing measurements distributed over space and time.
3:45 p.m.		BREAK
3:55 p.m.	Dartnell L. R. * Nordheim T. A. Mason J. P. Patel M. R.	Constraints on a Potential Aerial Biosphere on Venus: Cosmic Rays and Solar Ultraviolet Radiation [#4035] Presentation Recording Both UV and ionizing particle radiation are highly deleterious to life and may impose further constraints on the putative Venusian aerial habitable zone. Here we report results of two transport models dealing with cosmic ray and solar UV penetration and find that in terms of thermal gradient and radiation environment a potential HZ extends from 59 km to 48 km altitude. We suggest that this region should form the focus of future remote and in situ astrobiological investigations of Venus.
4:10 p.m.	Mogul R. * Limaye S. L. Lee Y. J. Pasillas M.	Potential for Habitability and Round-the-Clock Phototrophy in Venus’ Clouds [#4036] Presentation Recording We show that solar photon fluxes calculated across Venus’ cloud layers are sufficient for Earth-like photosynthesis, and that thermal emissions arising from below Venus’ clouds are potentially sufficient for lower-flux phototrophy. We also present interpretations to refractive index and radio occultation measurements that suggest, due to the presence of partly neutralized sulfuric acid, that acidity and water activity values in Venus’ aerosols may potentially be suitable for microbial growth.
4:25 p.m.	Milojevic T. * Treiman A. H. Limaye S.	Phosphorus in the Clouds of Venus: Potential for Bioavailability [#4043] Aerosol phase elements such as phosphorus, sulfur, and metals including iron are essential nutrients that could help sustain potential biodiversity in the cloud deck of Venus. We summarize our current understanding of the presence of phosphorus in the clouds of Venus and its role in a hypothetical atmospheric (bio)chemical cycle. The VeGa data indicate that a plentiful phosphorus layer exists within the lower Venusian clouds and exceeds minimum P abundances for terrestrial microbial life.
4:40 p.m.	Spacek J. * Benner S. A.	The Organic Carbon Cycle in the Atmosphere of Venus and Evolving Red Oil [#4052] Presentation Recording Organic reactions known in sulfuric acid at Venusian temperatures and pressures accounts for upper and lower hazes and the “mysterious” UV-blue absorber in Venusian clouds. In the lab this process yields fluorescence as a target for in situ analysis.
4:55 p.m.	Yang J. * Yan M.	Climate and Habitability of Venus-Like Slowly Rotating Planets [#4012] Presentation Recording Global-scale atmospheric general circulation model and cloud-resolving model simulations suggest that for slowly rotating rocky planets like Venus the inner edge of the habitable zone is much closer to the host stars. This is due to a stabilizing cloud feedback under weak Coriolis force and long daytime insolation.
5:10 p.m.	Limaye S. S. * Rothschild L. Mogul R. Head J. Way M. J.	Speculations on Adaptations of any Life on Venus, Past and Present [#4022] Presentation Recording We speculate about the adaptations that any life on the surface in the past must have gone through to survive until present as the environmental conditions changed including the rotation state which presumably controls the circadian clock.
5:25 p.m.		Wrap Up
5:30 p.m.		Adjourn Day 1

Note: The workshop will begin earlier on day two — 1:30 p.m. UTC.

BACK TO TOP

Tuesday, November 30, 2021

PANEL: “A DECADE OF VENUS EXPLORATION — A MULTI-AGENCY PERSPECTIVE” IN DEDICATION TO TOMMY THOMPSON

1:30 p.m. UTC

The panel will aim to discuss the respective space agencies’ Venus missions and the possible ways in which science synergism between these missions could maximize science return.

Moderator: Roger-Maurice Bonnet

Times	Presenters	Title
1:30 p.m.	Lori Glaze, Tirtha Das, Fabio Favata, Lev Zelenyi, Yoshifumi Saito	Panel: A Decade of Venus Exploration — A Multi-Agency Perspective in Dedication to Tommy Thompson Presentation Recording
3:00 p.m.		BREAK

Tuesday, November 30, 2021

MISSIONS TO VENUS

3:10 p.m. UTC

Conveners: Ludmila Zasova and Adriana Ocampo

This session will focus on updates from proposed and selected missions that will investigate the atmosphere of Venus and further develop the understanding of its habitability.

Times	*Authors (Denotes Presenter)**	Abstract Title and Summary
3:10 p.m.	Treiman A. *	Keynote: Venera-D Lander: Constraints on Site Selection Presentation Recording
3:40 p.m.	Arney G. N. * Garvin J. Getty S. Atreya S. Gilmore M. Grinspoon D. Hofmann A. G. Izenberg N. Kiefer W. Lorenz R. Malespin C. A. Ravine M. Trainer M. G. Webster C. R. Zahnle K.	The DAVINCI Mission to Venus and Connections to Venus Habitability [#4007] Presentation Recording The Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission was selected in NASA’s Discovery program. Launching later this decade, it will be the first U.S. spacecraft to enter the Venus atmosphere since 1978. DAVINCI will make detailed measurements of the Venus surface and atmosphere, revealing its current state and history, providing new insights into Venus habitability, and helping to place our sister planet into a larger cosmic context of exoplanets.
3:55 p.m.	Widemann T. * Ghail R. C. Wilson C. F. Titov D. V.	Atmospheric Studies with the EnVision Mission [#4042] Presentation Recording On June 10, 2021, the European Space Agency (ESA) announced the selection of EnVision as its newest medium-class science mission. VenSpec-H will focus on the volcanic and cloud forming gases and search for composition anomalies potentially related to the volcanic activity. VenSpec-U will investigate the upper atmosphere. The spatial and temporal behavior of H2SO4 (gaseous and liquid) below the cloud deck will be also investigated at 45-55 km.

Tuesday, November 30, 2021

MEASUREMENTS, INSTRUMENTS, AND MISSION CONCEPTS TO VENUS (Part 1)

4:10 p.m. UTC

Conveners: Oleg Korablev and Tibor Kremic

This session will focus on instrument and platform concepts that aim to understand the habitability of Venus and detect putative life.

Times	*Authors (Denotes Presenter)**	Abstract Title and Summary
4:10 p.m.	Vodopyanov K. L. *	Trace Molecular Sensor Based on Mid-Infrared/THz Frequency Combs [#4034] Presentation Recording We propose a new concept for in-situ trace gas detection based on laser frequency combs. The dual-comb spectroscopy (DCS) instrument will target, in one device, broadband MIR (3-20 µm) and THz (1-5 THz) regions of the spectrum, where strongest absorption resonances are found. The DCS concept will allow massively parallel identification of molecules and their isotopologues with high sensitivity, high specificity, real-time detection capability, and sub-Doppler spectral resolution.
4:25 p.m.	Simon K. Eshelman E. Sobron P. * Bretch A. Cassell A. Davila A. Gentry D. M. Iraci L. Mattioda A.	Real Time Cloud Composition Profiles with an Optofluidic Instrument [#4046] Presentation Recording Compact spectroscopic instrument to characterize the chemical composition of Venus’ cloud deck, including ppb-level detection of organic functional groups, in real time during dive-in missions.
4:40 p.m.		Wrap-Up
5:00 p.m.		Adjourn Day 2

BACK TO TOP

Wednesday, December 1, 2021

MEASUREMENTS, INSTRUMENTS, AND MISSION CONCEPTS TO VENUS (Part 2)

2:00 p.m. UTC

Conveners: Oleg Korablev and Tibor Kremic

This session will focus on instrument and platform concepts that aim to understand the habitability of Venus and detect putative life.

Times	*Authors (Denotes Presenter)**	Abstract Title and Summary
2:00 p.m.		Welcome
2:10 p.m.	Oleg Sedykh *	Keynote: Update on Venera-D Presentation Recording
2:40 p.m.	Sasaki S. * Enya K. Ohno S. Yoshimura Y. Yamagishi A. Miyakawa A.	Fluorescence Microscopic Observation of Model Microorganisms Suspended in Sulfuric Acid [#4027] Observation of microorganisms suspended in sulfuric acid was performed using fluorescence microscope and stains. Trials to reduce false positives will be reported.
2:55 p.m.	Baines K. H. * Cutts J. Byrne P. Dorsky L. O’Rourke J. Seager S. Wilson C.	Venus Cloud Explorer — Understanding Venus’s Habitable Zone (VHZ) via a Long-Lived In-Situ Aerial Observatory [#4048] Presentation Recording A long-duration in-situ mission to Venus’s Habitable Zone (VHZ) is presented, utilizing a variable-altitude balloon to throughly explore the VHZ over 52-62 km altitude, over all times-of-day, and over a wide range of latitudes (likely > 30 degrees) during its planned 100-day mission. Mass-spectrometer and TLS instruments perform a complete inventory of all molecules <300 Da to < 1 ppb, both in the atmosphere and within aerosol particles, and particle size distributions are obtained.
3:10 p.m.	Bullock M. A. * Elston J. S. Stachura M. Z.	Sustained In Situ Exploration of the Habitability of Venus’ Clouds [#4049] Presentation Recording We show how an aircraft can harvest energy in Venus’ atmosphere for sustained flight and perform in situ scientific measurements of the gases, aerosols, and habitability of Venus’ clouds.
3:25 p.m.		BREAK
3:35 p.m.	Esposito L. W. *	Investigating the Venus Clouds from Balloon and Orbit [#4033] Presentation Recording The combination of a fixed-altitude balloon with a cloud-synchronous Venus orbiter investigates the cloud chemistry, dynamics, radiation, climate, and the suitability of the cloud environment for life.
3:50 p.m.	Sorokin V. V. Skladnev D. A. * Karlov S. P. Kotsyurbenko O. R.	Conversion of Living Matter to Inanimate Material as the Method of Detection of Life Signs: Application to Venera-D Mission [#4017] Presentation Recording The authors propose the idea that only conversion of living matter to inanimate material can be the method for clearly confirming the presence of life in tested samples. As for the terrestrial type of living objects after biocidal treatment, most cell membranes are destroyed and components of the cytoplasm and intracellular structures are released. We propose the concept of an instrument set for detecting cellular forms in the clouds of Venus by gravimetry of native samples in comparison vis bactericidal processed aliquots.
4:05 p.m.	Gordon I. E. * Skinner F. S. Hargreaves R. J. Hashemi R. Rothman L. S.	HITRAN2020: Deciphering Spectra from the Cytherean Atmosphere [#4044] Presentation Recording The HITRAN2020 edition of molecular spectroscopic database provides enhanced tools for interpreting spectra of the Venusian atmosphere. A comprehensive overview of the important updates and remaining deficiencies in HITRAN relevant to the exploration of Venus will be provided.

Wednesday, December 1, 2021

POSTER LIGHTNING TALKS

4:20 p.m. UTC

Convener: Sara Port

Lightning Talk Presentations Recording

Times	*Authors (Denotes Presenter)**	*Abstract Title and Summary*
4:20 p.m.	Pouget T. *	Vesper: Multi-Experience Transport Mission Architecture in the Venusian Environment [#4013] This study presents a multi-objective Venusian mission architecture. It can deliver customer’s cubsat (1U to 12U) on several orbits and atmospheric entry point. This mission allows the researcher to propose directly the experiences answering their questions. This study presents the design of the transport platform, the distribution of costs per unit cubsat according to the target, management of the communications, and a proposal of cubsat air balloon inflation system.
4:23 p.m.	Voirin T. * Buchwald R. Titov D. Wielders A. Crouzet P. E.	EnVision: The New Medium-Class ESA/NASA Mission to Venus [#4018] EnVision is a Venus orbiter mission that will determine the nature and current state of geological processes on Venus in the present era, measure how those processes generate and sustain the inhospitable atmosphere and climate of Venus, and piece together the sequence of events — the geological history — that led to that current state.
4:26 p.m.	Shimolina A. * Ernst R. E. Antropova E. G. Braga C. H. G. El Bilali H.	Magmatic History of North-East Part of Theia Mons, Beta Regio, Venus [#4019] Theia Mons is a 2,5 km high 500 km across volcanic edifice centered on Beta Regio, and at the locus of triple junction rifting and a radiating dyke swarm. Detailed mapping 1:750 000 scale aims to reveal the emplacement history of Theia Mons with broader implications for the Beta Regio plume event.
4:29 p.m.	Malyshev D. G. * Ernst R. E. Braga C. H. G. Antropova E. G. El Bilali H.	Dyke Swarm History of Sanodiva Mons Region, Devana Chasma Quadrange V-29, Venus [#4023] The Magellan radar data allow detailed mapping of volcanoes and determination of their geological histories. Samodiva Mons (volcano), located (13.6º N, 291.0º E) at the southern end of Hyndla Regio in Devana Chasma Quadrangle V-29, was selected for detailed mapping at 1:500 000 of both its volcanic flows and graben-fissure systems. The latter, which are viewed to overlie dyke swarms, are the focus of the current mapping.
4:32 p.m.	Antropova E. G. * Braga C. H. G. Ernst R. E. Buchan K. L. El Bilali H. Head J. W.	A Newly Recognized 2 000 km Long Bolide Airburst Chain, Phoebe Regio, Venus [#4024] The study analyzes a NNE-SSW trending (2 000 km long, 500 km wide) chain of 12 circular “splotches” located in western Phoebe Regio on Venus. Their morphology is considered in detail, along with their possible origins. It is concluded that the splotches represent the airburst of a bolide arriving along a NNE or SSW trajectory.
4:35 p.m.	Braga C. H. G. * Antropova E. G. Ernst R. E. Buchan K. L. El Bilali H. Head J. W.	Preliminary Results and Timing Constraints from the Geological Mapping of the Volcano Atira Mons, Beta-Atla-Themis (BAT) Region, Venus [#4025] The large volcano Atira Mons is located on the NE portion of BAT region, Venus. Its flow apron reveals a complex and multi-stage volcanic history, which this work tries to unveil through detailed geological mapping on a scale 1:500,000. This will be an important input into the time-volume release of CO2 and SO2 into the atmosphere from volcanism and here we present a brief description of the volcano and its associated geological features, as well as preliminary results and interpretations.
4:38 p.m.	Rozhin V. E. * Ernst R. E. Braga C. H. G. Antropova E. G. El Bilali H.	History of Volcanism in Northern Asteria Regio, Venus [#4026] Asteria Regio, Venus is rich in volcanic centers, flow fields, and rifts including Hecate Chasma. Our mapping is at 10x higher resolution (1:500,000 scale) than previous mapping (1:5,000,000). The goal of our mapping is a detailed volcanic history of Asteria Regio, which will have relevance to Large Igneous Provinces (LIP) volcanism on Earth. Here we report on initial mapping of a flow field in the northern part of Asteria Regio.
4:41 p.m.	El Bilali H. * Ernst R. E. Buchan K. L. Head J. W.	Dyke Swarm History of Atla Regio, Venus: Insights into a Large Plume Head Event [#4028] Part of the BAT region, Atla Regio is a major mantle plume concentration featuring multiple volcanic centres and associated triple junction rifting. 26,000 extensional lineaments are mapped and grouped into sets representing radiating and circumferential dyke swarms. These are linked to the magmatic centres and are used to estimate the size of the underlying plume head associated with each centre, and to infer that a single plume head event is consistent with the magmatic history of Atla Regio.
4:44 p.m.	Slowik G. P. * Dabrowski P.	Selected Terrestrial Microorganisms as an Example of Potential Analogues of Venusian Microorganisms [#4037] The aim of the study is to select a group of terrestrial microorganisms with physical and biological parameters most similar to potential Venusian analogues.
4:47 p.m.	Nakley L. M. *	Venus Atmosphere Simulation with the Glenn Extreme Environment Rig [#4038] The Glenn Extreme Environment Rig (GEER) is a world class test facility designed to simulate harsh conditions such as the atmosphere found on Venus. GEER has been in operation since 2013 and has completed several successful simulation tests for science and technology users. To date, GEER has focused on Venus surface simulations but the rig may be adapted to achieve a wide range of other extreme environments on Venus and beyond.
4:50 p.m.	Kimmel E. L. * Head J. W. Fleeter R.	Exploring the Venus Atmosphere with a Venus Aero Vehicle (VAV): A Mission Concept for Low Cost, Multi-Year Venus Atmospheric Exploration [#4040] This paper details the conceptual design of an advanced space mission to explore the Venus atmosphere. The mission will incorporate advanced space technology such as electric propulsion and fully autonomous flight, as well as advanced instrumentation such as a miniature mass spectrometer to explore the Venus atmosphere. This proposal details specific scientific instrumentation and measurements which can be used to explore the composition and potential habitability of the Venus cloud layer.
4:53 p.m.	Limaye S. S. * Sokol D. Arenberg J.	Development of Cloud Mirco-Organism Census Sampling Platforms [#4055] Concepts for aerial platforms that can be tested and utilized on Earth to sample clouds for microorganism and can be adapted for Venus will be presented.
4:56 p.m.	King I. R. * Bywaters K. Zacny K. Seager S. Petkowski J.	Tape and Roller Sampling System for Flexible Venusian Atmosphere Aerosol Capture and Delivery [#4015] This abstract presents the conceptual design of an all-in-one sample collection and delivery system for use in capturing aerosols in the Venusian atmosphere. The system is highly flexible and may be adapted for use in many different mission architectures and instrument types and quantities.
4:59 p.m.	Yamauchi M. * Norberg O. Watanabe S. Laufer R. Ivchenko N. Enell C.-F.	Venus Laputa: A Sustainable N2-Filled Platform in the Venus Atmosphere [#4041] Traditional balloon cannot fly many months due to the gas-leak. To solve this, we propose to use N2 as the filling gas because it does not easily leak due to larger kinetic diameter (3.6 Å) than those of CO2 (3.3 Å) and He (2.6 Å). Furthermore, N2 (28 amu) is buoyant in CO2-dominant atmosphere (~40 amu), unlike the Earth. This opens up possibility of local production of N2 from Venus atmosphere (He ~ 3.5%), which may extend the platform lifetime to many years, as in-situ ”base.”
5:02 p.m.	George R. R. G. * Bagchi A. B.	Hypothesizing Possible Life Forms in Venusian Clouds [#4039] According to recent research, biosignature phosphine has been detected in lower Venus cloud layers where the temperature and pressure is conducive for lifeforms to exits. This abstract collates the data available and puts forward a hypothesis of how life, if present, would be and may have originated if present. Proposed lifeforms may be anaerobic sulphur-reducing chemoautotrophs which are extreme varieties of earthly extremophiles or completely different from life as we know it.
5:05 p.m.	Khrunyk Y. Y. Kotsyurbenko O. R.	Is Life on Venus Possible? From Earth Extremophiles to Venusian Clouds [#4054] Our review summarizes information on microorganisms inhabiting extreme Earth niches, such as Acidianus sp., Acidithiobacillus sp., Stygiolobus sp., Thermoplasmata sp. These microorganisms could have adapted to the conditions evolving on Venus.
5:08 p.m.		Q&A/Discussion
5:30 p.m.		Adjourn Day 3

BACK TO TOP

Thursday, December 2, 2021

PUTATIVE ORIGINS OF LIFE AND PAST HABITABILITY OF VENUS

2:00 p.m. UTC

Conveners: Mary Voytek and Yuliya Khrunyk

This session will focus on possible origins of life on Venus and what the habitability of Venus may have looked like in the past.

Times	*Authors (Denotes Presenter)**	Abstract Title and Summary
2:00 p.m.		Welcome
2:10 p.m.	Benner S. A. * Spacek J.	The Limits to Organic Life in the Solar System: From Cold Titan to Hot Venus [#4003] Presentation Recording Synthetic biology, physical organic chemistry, and other experimental sciences help assess here on Earth the probability of life in alien environments and guide our search for it in observational and mission astronomy. These have given us “Agnostic Life Finders” (ALFs) for worlds where environments are similar to Earth’s. However, they also guide a search for life in exotic environments. We will present by lab experiments showing organic processes that may support life in acidic Venusian clouds.
2:40 p.m.	Globus N. *	Homochirality, Cosmic Rays, and Venus [#4057] Recent ideas connecting the chirality of cosmic muons to a chiral bias in biological processes, and possible routes to detect chirality in astrophysical environments with a special focus on Venus will be discussed.
2:55 p.m.	Höning D. * Baumeister P. Grenfell J. L. Tosi N. Way M. J.	Habitability of an Early Stagnant-Lid Venus [#4032] Presentation Recording We model the coupled interior-atmosphere evolution of early Venus without plate tectonics. We find that silicate weathering could have kept the planet habitable for 900 Myr, followed by rapid metamorphic release of carbon from the crust, evaporation of water, and a rapid build-up of Venus’ thick, CO2-rich atmosphere as observed today.
3:10 p.m.	Kohler E. * Knudson C. Head J. W. Port S. Sohl L. Way M.	Stromatolites on Venus — An Experimental Look into Their Stability and Where to Investigate [#4050] We experimentally tested stromatolites at Venus conditions to see whether these morphological fossils could be recognized with instrumentation on future Venus missions — and identify optimal landing sites for their discovery.
3:25 p.m.		BREAK

Thursday, December 2, 2021

BIOSIGNATURES AT VENUS

3:30 p.m. UTC

Conveners: Rakesh Mogul and Daria Evdokimova

This session will focus on possible biosignatures on Venus, including the debated detection of phosphine.

Times	*Authors (Denotes Presenter)**	Abstract Title and Summary
3:30 p.m.	Graham H. *	Keynote: The Limits of Parsimony: Agnostic Pathways for Understanding Life Detection
4:00 p.m.	Petkowski J. J. * Bains W. Rimmer P. B. Seager S.	Towards an Explanation for Venusian Cloud Anomalies and Implications for the Habitability of the Clouds [#4006] We present a model for the chemistry of the atmospheric cloud layers of Venus while reconciling decades-long atmosphere anomalies. We predict that the clouds are not entirely made of conc. H2SO4, but of ammonium salts, resulting from biological production of NH3. The clouds are no more acidic than some terrestrial environments that harbor life. The model’s predictions for the abundance of gases in Venus’ atmosphere matches observation better than any previous model, and are readily testable.
4:15 p.m.	Jordan S. * Rimmer P. B. Shorttle O.	Metabolic Signatures of an Aerial Biosphere in the Clouds of Venus: A Self-Consistent Photo-Bio-Chemical Model [#4056] Presentation Recording It is useful to investigate whether a hypothetical biosphere in the clouds of Venus produces chemical changes in the atmosphere that are observable and diagnostic. We present the first self-consistent coupling of metabolic pathways to a full-atmosphere (0 - 115 km) model of Venus, utilizing plausible sulfur-based metabolisms found in the literature.
4:30 p.m.	Greaves J. S. *	Update on Phosphine in Venus’ Atmosphere [#4001] Presentation Recording The authors initiated in 2016 a remote spectroscopic search for PH3 in the atmosphere of Venus. The goal was to set a first limit on phosphine relevant to a hypothetical aerial biosphere. The surprising detection has been intensively followed up. We present the latest analyses of 2017-2020 datasets, with an update on inferred abundances and time variability.

Thursday, December 2, 2021

PANEL: PHOSPHINE AT VENUS

4:45 p.m. UTC

Moderator: Kandi Jessup

This panel will provide a focused discussion of potential sources for PH3 within Venus's clouds, relative to what we do and do not understand about Venus as a planetary system.

Times	Presenters	Title
4:45 p.m.	Clara Sousa-Silva, Giada Arney, Matt Pasek, Colin Wilson, Melissa Trainer, Kevin Zahnle	Panel: Phosphine at Venus Presentation Recording
5:30 p.m.		Adjourn Day 4

BACK TO TOP

Friday, December 3, 2021

EVOLUTION OF THE VENUSIAN ATMOSPHERE

2:00 p.m. UTC

Conveners: Allan Treiman and Dmitry Gorinov

This session will focus on how the Venusian atmosphere has evolved through time, including geological effects on the atmosphere.

Times	*Authors (Denotes Presenter)**	Abstract Title and Summary
2:00 p.m.		Welcome
2:10 p.m.	Way M. J. *	Did an Ancient Habitable Venus Provide the Seeds for Life Today? [#4020] Presentation Recording Recent possible detections of PH3 have spurred interest in the potential for life in the clouds of Venus. We have used forward modeling to investigate the possibilities of a temperate Venusian climate in its deep past. This affords us the opportunity to discuss the possibility for an early habitable Venus and its implications for habitability in the cloud layers today.
2:40 p.m.	Weller M. B. * Kiefer W. S.	From Whiffs to Pulses: Links Between Tectonic Evolution, Outgassing, and Atmospheric Development [#4014] Venus asunder/Magma from great depth ascends/Clouds spring forth, changing.
2:55 p.m.	Head J. W. * Wilson L. Ivanov M. A. Wordsworth R.	Formation and Stability of the Venus Atmosphere: Insights from the Geological Record and Implications for Evidence of Life on Venus [#4021] Presentation Recording We assume the hypothesis that Venus was once Earth-like, examine the geologic record to address when and how the transition to the decidedly non-Earth-like conditions of today could have taken place, and assess the implications for preservation of evidence of fossil life on the surface or current biological activity in the Venus atmosphere.
3:10 p.m.	Ernst R. E. * Buchan K. L. El Bilali H. Head J. W.	The Implications of Applying a Large Igneous Province (LIP) Context for Volcanism, Tectonics, and Atmospheric Evolution on Venus [#4029] Recording Voluminous Venusian magmatism may be analogous to Large Igneous Provinces (LIPs) on Earth. We consider implications of the terrestrial LIP paradigm for the Venusian geological record, and for the evolution of the Venusian atmosphere through input of CO2 and SO2 from LIP-style volcanism.
3:25 p.m.	Turbet M. * Bolmont E. Chaverot G. Ehrenreich D. Leconte J. Marcq E.	Day-Night Cloud Asymmetry Inhibits Early Ocean Formation on Venus [#4051] Recording In this contribution, we will present the results of new 3-D Global Climate Model (GCM) simulations of very early Venus. The simulations reveal that clouds preferentially form on the nightside of Venus, which prevented the planet to ever have surface liquid water oceans. This work also has important implications for the past habitability of Earth and exoplanets.
3:40 p.m.	Hallsworth J. *	Venus’s Clouds Are an Order of Magnitude Beyond the Acidity Limit, and Two Orders of Magnitude Below the Water-Activity Limit, for Active Life [#4058] Presentation Recording Venus's clouds (77.8-99.2% w/w sulphuric acid; <0.004 water activity) are an order of magnitude beyond the 11.5% (w/w) acidity limit, and two orders of magnitude below the 0.585 water-activity limit, for active life on Earth; as shown in Figure 3 of Hallsworth et al. (2021) Nat. Astron., 5, 665–675.

Friday, December 3, 2021

PANEL: WATER ON VENUS

3:55 p.m. UTC

Moderator: Mark Bullock

The panel will discuss the past and present water availability at Venus which has important implications on the origin and evolution of putative life on Venus.

Times	Presenters	Title
3:55 p.m.	Michael Way, Martin Turbet, John Hallsworth, Chris McKay, Paul Rimmer	Panel: Water on Venus Presentation Recording
4:40 p.m.		Break

Friday, December 3, 2021

CONCLUSION

4:55 p.m. UTC

Times	Presentation
4:55 p.m.	Scribe Summary Recording
5:05 p.m.	Meeting Wrap Up, Review of Actions and Next Steps
5:30 p.m.	Adjourn Day 5

BACK TO TOP

PRINT ONLY

Authors (*Denotes Presenter)

Abstract Title and Summary

Pelawatta A-T.

Cloud Layer Habitability of Venus; There May Be Life on It [#4004]
Venus is our twin sister with a great astrobiological value. Before billion years ago, Venus might contain liquid surface water, but present day it is a dry planet. However, Venusian clouds show possible sign of life with sufficient temperature, pressure, and some other requirements. Some of the terrestrial microbes show adaptations for the marginal environments that are similar to the Venusian atmospheric conditions.

BACK TO TOP