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Petkowski JJ, Seager S, Grinspoon DH, Bains W, Ranjan S, Rimmer PB, Buchanan WP, Agrawal R, Mogul R, Carr CE. Astrobiological Potential of Venus Atmosphere Chemical Anomalies and Other Unexplained Cloud Properties. ASTROBIOLOGY 2024; 24:343-370. [PMID: 38452176 DOI: 10.1089/ast.2022.0060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
Long-standing unexplained Venus atmosphere observations and chemical anomalies point to unknown chemistry but also leave room for the possibility of life. The unexplained observations include several gases out of thermodynamic equilibrium (e.g., tens of ppm O2, the possible presence of PH3 and NH3, SO2 and H2O vertical abundance profiles), an unknown composition of large, lower cloud particles, and the "unknown absorber(s)." Here we first review relevant properties of the venusian atmosphere and then describe the atmospheric chemical anomalies and how they motivate future astrobiology missions to Venus.
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Affiliation(s)
- Janusz J Petkowski
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Faculty of Environmental Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland
- JJ Scientific, Mazowieckie, Warsaw, Poland
| | - Sara Seager
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | | | - William Bains
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- School of Physics and Astronomy, Cardiff University, Cardiff, UK
| | - Sukrit Ranjan
- Lunar and Planetary Laboratory, Department of Planetary Sciences, University of Arizona, Tucson, Arizona, USA
| | - Paul B Rimmer
- Department of Earth Sciences, University of Cambridge, Cambridge, UK
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Weston P Buchanan
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- School of Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana, USA
| | - Rachana Agrawal
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Rakesh Mogul
- California Polytechnic University, Pomona, California, USA
| | - Christopher E Carr
- School of Aerospace Engineering and School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
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Milojevic T, Treiman AH, Limaye SS. Phosphorus in the Clouds of Venus: Potential for Bioavailability. ASTROBIOLOGY 2021; 21:1250-1263. [PMID: 34342520 DOI: 10.1089/ast.2020.2267] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Aerosol phase elements such as phosphorus (P), sulfur (S), and metals including iron (Fe) are essential nutrients that could help sustain potential biodiversity in the cloud deck of Venus. While the presence of S and Fe in the venusian cloud deck has been broadly discussed (Zasova et al., 1981; Krasnopolsky, 2012, 2013, 2016, 2017; Markiewicz et al., 2014), less attention has been given to the presence of P in the aerosols and its involvement in the multiphase chemistry of venusian clouds and potential sources of P deposition in the venusian atmosphere. A detailed characterization of phosphorus atmospheric chemistry in the cloud deck of Venus is crucial for understanding its solubility and bioavailability for potential venusian cloud microbiota (Schulze-Makuch et al., 2004; Grinspoon and Bullock, 2007; Limaye et al., 2018). We summarize our current understanding of the presence of P in the clouds of Venus and its role in a hypothetical atmospheric (bio)chemical cycle. The results of the VeGa lander measurements are put into perspective with regard to nutrient limitation for a potential biosphere in venusian clouds. Our work combines the results of the VeGa measurements and focuses on P as an inorganic nutrient component and its potential sources and chemical behavior as part of multiple transformations of atmospheric chemistry. The VeGa data indicate that a plentiful phosphorus layer exists within a layer that reaches into the lower venusian clouds and exceeds minimum P abundances for terrestrial microbial life. Extreme acidification of airborne phases in the atmosphere of Venus may facilitate P solubilization and its bioavailability for a potential ecosystem in venusian clouds. Further sampling and P abundance measurements in the atmosphere of Venus would improve our knowledge of P speciation and facilitate determination of a bioavailable fraction of P detected in venusian clouds. The previous results deserve further experimental and modeling analyses to diminish uncertainties and understand the rates of atmospheric deposition of P and its role in a potential venusian cloud ecosystem.
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Affiliation(s)
- Tetyana Milojevic
- Space Biochemistry Group, Department of Biophysical Chemistry, University of Vienna, Vienna, Austria
| | | | - Sanjay S Limaye
- Space Science and Engineering Center, University of Wisconsin, Madison, Wisconsin, USA
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Filiberto J, Trang D, Treiman AH, Gilmore MS. Present-day volcanism on Venus as evidenced from weathering rates of olivine. SCIENCE ADVANCES 2020; 6:eaax7445. [PMID: 31922004 PMCID: PMC6941908 DOI: 10.1126/sciadv.aax7445] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 11/07/2019] [Indexed: 05/20/2023]
Abstract
At least some of Venus' lava flows are thought to be <2.5 million years old based on visible to near-infrared (VNIR) emissivity measured by the Venus Express spacecraft. However, the exact ages of these flows are poorly constrained because the rate at which olivine alters at Venus surface conditions, and how that alteration affects VNIR spectra, remains unknown. We obtained VNIR reflectance spectra of natural olivine that was altered and oxidized in the laboratory. We show that olivine becomes coated, within days, with alteration products, primarily hematite (Fe2O3). With increasing alteration, the VNIR 1000-nm absorption, characteristic of olivine, also weakens within days. Our results indicate that lava flows lacking VNIR features due to hematite are no more than several years old. Therefore, Venus is volcanically active now.
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Affiliation(s)
- Justin Filiberto
- Lunar and Planetary Institute, USRA, 3600 Bay Area Blvd., Houston, TX 77058, USA
- Corresponding author.
| | - David Trang
- University of Hawai‘i at Mānoa/Hawai’i Institute of Geophysics and Planetology, 1680 East-West Rd., Honolulu, HI 96822, USA
| | - Allan H. Treiman
- Lunar and Planetary Institute, USRA, 3600 Bay Area Blvd., Houston, TX 77058, USA
| | - Martha S. Gilmore
- Department of Earth and Environmental Sciences, Wesleyan University, 265 Church Street, Middletown, CT 06457, USA
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Limaye SS, Mogul R, Smith DJ, Ansari AH, Słowik GP, Vaishampayan P. Venus' Spectral Signatures and the Potential for Life in the Clouds. ASTROBIOLOGY 2018; 18:1181-1198. [PMID: 29600875 PMCID: PMC6150942 DOI: 10.1089/ast.2017.1783] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/11/2018] [Indexed: 05/17/2023]
Abstract
The lower cloud layer of Venus (47.5-50.5 km) is an exceptional target for exploration due to the favorable conditions for microbial life, including moderate temperatures and pressures (∼60°C and 1 atm), and the presence of micron-sized sulfuric acid aerosols. Nearly a century after the ultraviolet (UV) contrasts of Venus' cloud layer were discovered with Earth-based photographs, the substances and mechanisms responsible for the changes in Venus' contrasts and albedo are still unknown. While current models include sulfur dioxide and iron chloride as the UV absorbers, the temporal and spatial changes in contrasts, and albedo, between 330 and 500 nm, remain to be fully explained. Within this context, we present a discussion regarding the potential for microorganisms to survive in Venus' lower clouds and contribute to the observed bulk spectra. In this article, we provide an overview of relevant Venus observations, compare the spectral and physical properties of Venus' clouds to terrestrial biological materials, review the potential for an iron- and sulfur-centered metabolism in the clouds, discuss conceivable mechanisms of transport from the surface toward a more habitable zone in the clouds, and identify spectral and biological experiments that could measure the habitability of Venus' clouds and terrestrial analogues. Together, our lines of reasoning suggest that particles in Venus' lower clouds contain sufficient mass balance to harbor microorganisms, water, and solutes, and potentially sufficient biomass to be detected by optical methods. As such, the comparisons presented in this article warrant further investigations into the prospect of biosignatures in Venus' clouds.
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Affiliation(s)
- Sanjay S. Limaye
- Space Science and Engineering Center, University of Wisconsin, Madison, Wisconsin
| | - Rakesh Mogul
- Chemistry and Biochemistry Department, California State Polytechnic University, Pomona, Pomona, California
| | - David J. Smith
- Space Biosciences Research Branch, NASA Ames Research Center, Moffett Field, California
| | - Arif H. Ansari
- Precambrian Palaeobotany Laboratory, Birbal Sahni Institute of Palaeosciences, Lucknow, India
| | | | - Parag Vaishampayan
- Biotechnology and Planetary Protection Group, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
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Limaye SS, Watanabe S, Yamazaki A, Yamada M, Satoh T, Sato TM, Nakamura M, Taguchi M, Fukuhara T, Imamura T, Kouyama T, Lee YJ, Horinouchi T, Peralta J, Iwagami N, Hashimoto GL, Takagi S, Ohtsuki S, Murakami SY, Yamamoto Y, Ogohara K, Ando H, Sugiyama KI, Ishii N, Abe T, Hirose C, Suzuki M, Hirata N, Young EF, Ocampo AC. Venus looks different from day to night across wavelengths: morphology from Akatsuki multispectral images. EARTH, PLANETS, AND SPACE : EPS 2018; 70:24. [PMID: 31983884 PMCID: PMC6954018 DOI: 10.1186/s40623-018-0789-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 01/24/2018] [Indexed: 05/28/2023]
Abstract
Since insertion into orbit on December 7, 2015, the Akatsuki orbiter has returned global images of Venus from its four imaging cameras at eleven discrete wavelengths from ultraviolet (283 and 365 nm) and near infrared (0.9-2.3 µm), to the thermal infrared (8-12 µm) from a near-equatorial orbit. The Venus Express and Pioneer Venus Orbiter missions have also monitored the planet for long periods but from polar or near-polar orbits. The wavelength coverage and views of the planet also differ for all three missions. In reflected light, the images reveal features seen near the cloud tops (~ 70 km altitude), whereas in the near-infrared images of the nightside, features seen are at mid- to lower cloud levels (~ 48-60 km altitude). The dayside cloud cover imaged at the ultraviolet wavelengths shows morphologies similar to what was observed from Mariner 10, Pioneer Venus, Galileo, Venus Express and MESSENGER. The daytime images at 0.9 and 2.02 µm also reveal some interesting features which bear similarity to the ultraviolet images. The nighttime images at 1.74, 2.26 and 2.32 µm and at 8-12 µm reveal features not seen before and show new details of the nightside including narrow wavy ribbons, curved string-like features, long-scale waves, long dark streaks, isolated bright spots, sharp boundaries and even mesoscale vortices. Some features previously seen such as circum-equatorial belts (CEBs) and occasional areal brightenings at ultraviolet (seen in Venus Express observations) of the cloud cover at ultraviolet wavelengths have not been observed thus far. Evidence for the hemispheric vortex organization of the global circulation can be seen at all wavelengths on the day- and nightsides. Akatsuki images reveal new and puzzling morphology of the complex nightside cloud cover. The cloud morphologies provide some clues to the processes occurring in the atmosphere and are thus, a key diagnostic tool when quantitative dynamical analysis is not feasible due to insufficient information.
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Affiliation(s)
- Sanjay S. Limaye
- Space Science and Engineering Center, University of Wisconsin, Madison, WI 53706 USA
| | - Shigeto Watanabe
- Space Information Center, Hokkaido Information University, Ebetsu, Hokkaido 069-8585 Japan
| | - Atsushi Yamazaki
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Manabu Yamada
- Planetary Exploration Research Center, Chiba Institute of Technology, 2-17-1, Tsudanuma, Narashino, Chiba 275-0016 Japan
| | - Takehiko Satoh
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Takao M. Sato
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Masato Nakamura
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Makoto Taguchi
- College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo, 171-8501 Japan
| | - Tetsuya Fukuhara
- College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo, 171-8501 Japan
| | - Takeshi Imamura
- Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo, Kiban-tou 4H7, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 Japan
| | - Toru Kouyama
- Artificial Intelligence Research Center, National Institute of Advanced Industrial Science and Technology, Tokyo, Japan
| | - Yeon Joo Lee
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
- Present Address: Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo, Kiban-tou 4E5, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 Japan
| | - Takeshi Horinouchi
- Faculty of Environmental Earth Science, Hokkaido University, N10W5, Sapporo, Hokkaido 060-0810 Japan
| | - Javier Peralta
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Naomoto Iwagami
- School of Commerce, Senshu University, 2-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8580 Japan
| | - George L. Hashimoto
- Department of Earth Sciences, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama, 700-8530 Japan
| | - Seiko Takagi
- Tokai University, Research and Information Center, 4-1-1 Kitakaname, Hiratsuka-shi, Kanagawa 259-1292 Japan
| | - Shoko Ohtsuki
- School of Commerce, Senshu University, 2-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8580 Japan
| | - Shin-ya Murakami
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Yukio Yamamoto
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Kazunori Ogohara
- School of Engineering, University of Shiga Prefecture, Hikone, Japan
| | - Hiroki Ando
- Faculty of Science, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto-City, 603-8555 Japan
| | - Ko-ichiro Sugiyama
- Department of Information Engineering, National Institute of Technology, Matsue College, 14-4 Nishi-Ikuma, Matsue, Shimane 690-8518 Japan
| | - Nobuaki Ishii
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Takumi Abe
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Chikako Hirose
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Makoto Suzuki
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1, Yoshinodai, Chuo-ku, Sagamihara, 252-5210 Japan
| | - Naru Hirata
- ARC-Space, CAIST, The University of Aizu, 90 Kami-Iawase, Tsuruga, Ikki-machi, Aizu-Wakamatsu, Fukushima 965-8580 Japan
| | - Eliot F. Young
- Southwest Research Institute, 1050 Walnut St., Suite 300, Boulder, CO 80302 USA
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