Life on Venus

Cockell, Charles S.

doi:10.1016/s0032-0633(99)00036-7

Cited by 126 publications

(99 citation statements)

References 63 publications

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“…Their authors conclude that the possibility to meet life on Venus is not excluded [36], for instance, life in its microbial forms flows high in the atmosphere. There is also a possibility that life evolved from the early stages of the history of the planet accommodating to slowly changing conditions.…”

Section: Hypothetical Floramentioning

confidence: 99%

Possible Signs of Life on the Planet Venus

Ksanfomality¹

2013

IJAA

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It is possible, the question on the existence of extraterrestrial life will be answered not as a result of its search for in other worlds removed by distances of dozens of parsecs but on the surface of Venus, i.e., of the nearest planet of the Solar system. The search for "habitable zones" in extrasolar planetary systems is based on the postulate on "normal" physical conditions, i.e., the pressure, temperature, and maybe atmospheric composition similar to those on Earth. But could not such an approach be a kind of "terrestrial chauvinism"? Considering the conditions on Venus as a possible analogue of physical conditions on low-orbiting exoplanets of the "super-Earths" type, a new analysis of Venusian surface panoramas' details has been made. These images were produced by the VENERA landers in 1975 and 1982. A few relatively large objects were found with size ranging from a decimeter to half meter and with unusual morphology. The objects were observed in some images, but were absent in the other or altered their shape. The article presents the obtained results and analyzes the evidence of reality of these objects.

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Section: Hypothetical Floramentioning

confidence: 99%

Possible Signs of Life on the Planet Venus

Ksanfomality¹

2013

IJAA

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“…The environmental regime of the current venusian surface, however, is not suitable for organic life, and it is the lower or middle global cloud deck that has been proposed as a potential atmospheric habitable zone (e.g., Cockell, 1999;SchulzeMakuch et al, 2004). Between 48 and 57 km altitude, local physical conditions are conducive to life, with atmospheric pressure between 0.1 and 1 bar and temperature within the range 0-60°C.…”

Section: Venus Atmosphere Ionizationmentioning

confidence: 99%

“…A venusian biosphere could reside in the overlap region between the cloud layer and habitable temperature regime but lies near the peak in atmospheric ionization from cosmic radiation (blue). Diagram constructed using temperature profile from Prinn and Fegley (1987), CR ionization modeling from Upadhyay et al (1994), and habitable zone discussion in Cockell (1999). Color images available online at www.liebertonline .com/ast 562 DARTNELL profile in Yelle et al, 1997, and stated as such by Krasnopolsky, 2009) is believed to have a similar chemistry to Earth's primordial atmosphere (Molina-Cuberos et al, 1999b).…”

Section: Titan Atmosphere Ionizationmentioning

confidence: 99%

Ionizing Radiation and Life

2011

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Ionizing radiation is a ubiquitous feature of the Cosmos, from exogenous cosmic rays (CR) to the intrinsic mineral radioactivity of a habitable world, and its influences on the emergence and persistence of life are wideranging and profound. Much attention has already been focused on the deleterious effects of ionizing radiation on organisms and the complex molecules of life, but ionizing radiation also performs many crucial functions in the generation of habitable planetary environments and the origins of life. This review surveys the role of CR and mineral radioactivity in star formation, generation of biogenic elements, and the synthesis of organic molecules and driving of prebiotic chemistry. Another major theme is the multiple layers of shielding of planetary surfaces from the flux of cosmic radiation and the various effects on a biosphere of violent but rare astrophysical events such as supernovae and gamma-ray bursts. The influences of CR can also be duplicitous, such as limiting the survival of surface life on Mars while potentially supporting a subsurface biosphere in the ocean of Europa. This review highlights the common thread that ionizing radiation forms between the disparate component disciplines of astrobiology.

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“…A warm ocean may have existed for several hundred million years or longer until it evaporated away due to a run-away moist greenhouse effect and an increase in solar luminosity (Kasting 1988). The reduction in surface water would have prevented the formation of carbonates, allowing CO 2 partial pressures to increase by volcanic outgassing, further increasing the greenhouse effect (Cockell 1999). Eventually, the evaporated water dissociated in the atmosphere under the influence of radiation.…”

Section: Venusmentioning

confidence: 99%

“…HCl and HF have been detected as trace compounds. Cockell (1999) pointed out that the water vapor should also contain significant amounts of carbon, nitrogen and phosphorus. Perturbations in the abundance of atmospheric water vapor and the sulfur gases (e.g.…”

Section: Venusmentioning

confidence: 99%

Extraterrestrial hydrogeology

et al. 2005

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Subsurface water processes are common for planetary bodies in the solar system and are highly probable for exoplanets (planets outside the solar system). For many solar system objects, the subsurface water exists as ice. For Earth and Mars, subsurface saturated zones have occurred throughout their planetary histories. Earth is mostly clement with the recharge of most groundwater reservoirs from ample precipitation during transient iceand hot-house conditions, as recorded through the geologic and fossilized records. On the other hand, Mars is mostly in an ice-house stage, which is interrupted by endogenic-driven activity. This activity catastrophically drives short-lived hydrological cycling and associated climatic perturbations. Regional aquifers in the Martian highlands that developed during past, more Earth-like conditions delivered water to the northern plains. Water was also cycled to the South Polar Region during changes in climate induced by endogenic activity and/or by changes in Mars' orbital parameters. Venus very likely had a warm hydrosphere for hundreds of millions of years, before the development of its current extremely hot atmosphere and surface. Subsequently, Venus lost its hydrosphere as solar luminosity increased and a run-away moist greenhouse took effect. Subsurface oceans of water or ammonia-water composition, induced by tidal forces and radiogenic heating, probably occur on the larger satellites Europa, Ganymede, Callisto, Titan, and Triton. Tidal forces operating between some of the small bodies of the outer solar system could also promote the fusion of ice and the stability of inner liquid-water oceans.RØsumØ Les processus de subsurface impliquant l'eau sont communs pour les corps planØtaires du syst me solaire et sont tr s probables sur les exoplan tes (plan tes en dehors du syst me solaire). Pour plusieurs objets du syst mes solaire, l'eau de subsurface est prØsente sous forme de glace. Pour la Terre et Mars, les zones saturØes de subsurface apparaissent à travers toute leur histoire planØtaire. La Terre est particuli rement clØmente avec la recharge des rØservoirs, avec de amples prØcipitations, des conditions glaciaires et de fortes chaleurs, comme l'atteste les enregistrements gØologiques et palØontologiques. D'un autre côtØ, Mars se trouve dans une phase essentiellement glaciaire, qui est interrompue par des activitØs contraintes par les phØnom nes endogØniques. Cette activitØ conduit de mani re catastrophique à des cycles hydrologiques et à des perturbations climatiques brutaux. Les aquif res rØgionaux dans les haute terres martiennes qui se sont formØs dans des conditions similaires aux conditions terrestres, alimentent les plaines du Nord. Resumen Los procesos hídricos subsuperficiales son comunes en cuerpos planetarios del sistema solar y son altamente probables para exoplanetas (planetas fuera del sistema solar). Para muchos cuerpos del sistema solar, el agua subsuperficial existe como hielo. Para la Tierra y Marte han ocurrido zonas saturadas subsuperficiales a travØ...

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Life on Venus

Cited by 126 publications

References 63 publications

Possible Signs of Life on the Planet Venus

Possible Signs of Life on the Planet Venus

Ionizing Radiation and Life

Extraterrestrial hydrogeology

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