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Ultra-Low-Frequency Waves at Venus and Mars
Dubinin, E.; Fraenz, M.
Mars and Venus have no global magnetic field. The solar wind interacts directly with their ionospheres and atmospheres, inducing magnetospheres by a pileup of the interplanetary magnetic field. The first measurements of the ultra-low-frequency activity on Mars were made by the Phobos-2 spacecraft. This chapter investigates the wave observations re…
Atmospheric composition, chemistry, and clouds
Esposito, Larry W.; Yung, Yuk L.; Mills, Franklin P.
Venus' atmosphere has a rich chemistry involving interactions among sulfur, chlorine, nitrogen, hydrogen, and oxygen radicals. The chemical regimes in the atmosphere range from ion-neutral reactions in the ionosphere to photochemistry in the middle atmosphere to thermal equilibrium chemistry and surface-atmosphere reactions in the lower atmosphere…
Astrobiology and Venus exploration
Bullock, Mark A.; Grinspoon, David H.
For hundreds of years prior to the space age, Venus was considered among the most likely homes for extraterrestrial life. Since planetary exploration began, Venus has not been considered a promising target for Astrobiological exploration. However, Venus should be central to such an exploration program for several reasons. At present Venus is the o…
Radiation in the atmosphere of Venus
Bullock, Mark A.; Crisp, David; Taylor, Fredric W. +3 more
This chapter reviews the observations of the radiative fluxes inside and outside the Venusian atmosphere, along with the available data about the planetary energy balance and the distribution of sources and sinks of radiative energy. We also briefly address the role of the heat budget on the atmospheric temperature structure, global circulation, t…
Geochemistry of Venus' Surface: Current limitations as future opportunities
Treiman, Allan H.
Geochemical data about Venus' surface materials are quite limited and of poor precision. The Venera and VEGA lander missions (sources of the available data) were engineering and scientific triumphs, but their chemical analyses of the Venus surface do not permit detailed confident interpretation, such as are routine for terrestrial analyses and MER…
Tectonic and thermal evolution of Venus and the role of volatiles: Implications for understanding the terrestrial planets
Sotin, Christophe; Stofan, Ellen R.; Smrekar, Suzanne E. +5 more
Venus is similar to Earth in size and bulk composition. The dramatic differences between the two planets indicate that planetary size alone does not control geologic evolution. Earth's geology is dominated by plate tectonics, or active lid convection. The crater retention age of Venus demonstrates that the planet has been very geologically active …
Venus atmosphere dynamics: A continuing enigma
Bougher, S. W.; Del Genio, A. D.; Limaye, S. S. +5 more
The dynamics of the Venus atmosphere presents a major unsolved problem in planetary science: the so-called superrotation of the lower atmosphere and its transition to a subsolar-to-antisolar circulation in the upper atmosphere. (In this paper we place the dividing line between the lower and upper atmosphere at 90-100 km altitude (pressure 0.39 to …
Surface evolution of Venus
Basilevsky, Alexander T.; McGill, George E.
This chapter contains short descriptions of material units and structures observed on the surface of Venus as well as an abbreviated history of discoveries, that led to the current knowledge of this planet's geology. It is shown that observed units and structures are broadly similar and commonly exhibit similar age sequences in different regions o…
Venus upper atmosphere and plasma environment: Critical issues for future exploration
Luhmann, J. G.; Russell, C. T.; Cravens, T. E. +2 more
This chapter briefly summarizes our state of knowledge about the upper atmosphere and plasma environment of Venus. This is followed by a discussion of some of the outstanding remaining issues in the field beginning with the Venus Express epoch and continuing to Planet C and beyond. We compare with other planets, especially Mars, and emphasize open…
Technology perspectives in the future exploration of Venus
Cutts, James A.; Balint, Tibor S.; Chassefiere, Eric +1 more
Science goals to understand the origin, history and environment of Venus have been driving international space exploration missions for over 40 years. Today, Venus is still identified as a high priority science target in NASA's Solar System Exploration Roadmap, and clearly fits scientific objectives of ESA's Cosmic Vision Program in addition to th…