For Venus

Fig. 8.3. The basis of linear unmixing. Unnormalized emission spectra of the three capillaries are shown in panel A. The linear unmixing algorithm is based on the hypothesis that a complex emission spectrum (an emission spectrum of a sample containing 2 or more fluorophores) can be modeled as a weighted sum of the emission spectra of the individual fluorophores present. Thus, the Mix spectrum should be the sum of the Cerulean and Venus spectra after each is multiplied by an abundance factor. In panel B the abundance factor for Venus is held at a value of 1, while the value of the Cerulean abundance factor is varied from 0.6 to 1.4. Because the Cerulean and Venus capillaries each contained 10 /iM of fluorophore, an abundance range of 0.6-1.4 corresponds to a concentration range of 6-14 /iM. In panel C the Cerulean abundance factor is held at a value of 1 (10 /rM) while the abundance factor for Venus was altered from 0.2 to 1 (2-10 /rM). Note that when the Cerulean spectrum was multiplied by 1 (corresponding to 10 /rM) and added to the Venus spectrum multiplied by 0.6 (corresponding to 6 /rM), the linear unmixing model matched the complex spectrum measured for the mix capillary.

He reached for the handle. Brace yourself for Venus In Splendor. ... 

Assessment of Planetary Protection Requirements for Venus Missions Letter Report (2006)... 

All of the clouds are low density, because the visibility inside the densest region of the clouds is a few kilometers. The average and maximum optical depths (t) in visible light of all cloud layers are 29 and 40, respectively, versus average and maximum t values of 6 and 350 for terrestrial clouds. Average mass densities for Venus clouds are 0.01-0.02 g m versus an average mass density of 0.1-0.5 g m for fog clouds on Earth. Venus cloud layers are typically divided into the subcloud haze (32-48 km), the lower cloud (48-51 km), middle cloud (51-57 km), upper cloud (57-70 km), and upper haze (70-90 km). 

Figure 2 Distribution of surface area as a function of altitude for Venus, i.e., the hypsometric curve (after Fegley and Treiman, 1992) (reproduced by permission of American Geophysical Union from Geophysical Monograph...

Figure 1 Noble-gas abundances in planetary atmospheres and Cl chondrites, plotted as the atom concentration relative to Si and divided by the corresponding solar ratio. Note that ranges of Kr and Xe values are shown for Venus (source Pepin, 1991).

At the time, more than a dozen planetary satellites had already been discovered for Jupiter, Saturn, Uranus, and Neptune. None had been found for Venus or Mercury, nor were they likely to be found, given the proximity of these planets to the Sun. Mars likewise had no satellites. .. or, at least, none that had yet been discovered. 

The symbol for Venus includes two components from the Metaphysical tradition the cross of earth and the circle of spirit. Most people today associate it with the biological symbol for woman. 

Are any if the singularities near values of parameters that might be relevant to real planets If we adopt parameters for this artificial model that approximate the bulk properties of the Earth, we would have ggR/r = 5 and n/ — 1 (Kaula 1968). In Figure 6, those values plot just below the lowest curve for the locus of a singularity, as indicated by the Earth symbol, . Note that bulk parameters for Venus, would plot close to the same point. If such a body were only a few 10 s of percent larger in radius, it would be at a singularity. In principle, an infinitesimal passing body could raise a substantial tide. 

The pattern exhibited by Mars closely follows that of the Earth, with a near-solar Xe/Kr ratio. The available data for Venus likewise suggest solar-like Xe/Kr, although uncertainties are large. Despite these uncertanties, however, it seems clear that Venus differs markedly from the other two terrestrial planets in having an Ar/Kr ratio that is also close to solar. 

The compositional characteristics of an icy planetesimal source in comet accretion models for Venus, discussed below, require occlusion of nebular noble gases with approximately unfractionated elemental ratios for Ar Kr Xe but much lower Ne. Thermodynamic modeling suggests that noble gases incorporated in clathrates do indeed have low Ne/Ar ratios, but do not reflect ambient gas-phase compositions for Xe/Ar and Kr/Ar and instead are strongly enriched in the heavier species (Lunine and Stevenson... 

Clathrated gases therefore appear unlikely to be the source of atmospheric noble gases, at least for Venus, and one must appeal to physical adsorption on ice. 

See also the sigils used by the alcheiriats for COPPER, a term which is synonymous for Venus. 

NASA s Magellan spaceaaft eventually bound for Venus suffered a fire during ground testing. A technician incorrectly mated high- and low-voltage lines. He reached around into the back of the spaceaaft—a blind mate, the connectors were of the same size and keyed the same— and connected the cables. Unable to visually verify the miss-mate, he powered on the test equipment and created a fire to the 400M spacecraft. 

For Venus, there are difficulties in reconciling the observed thermal structure with the calculated heating efficiencies (Fox 1988). Important uncertainties attend the energetics of the quenching reaction. 

Agreement with the limited data for Mars is readily achieved (Fox and Dalgarno 1979). For Venus the agreement between the model ion densities and the measurements is broadly satisfactory when reactions of metastable ions are included (Fox 1982b) though there is a tendency for the models to underestimate the C+ densities (Paxton 1985). The charge transfer reaction... 

All substantial planetary atmospheres in the Solar System have well-developed tropospheres, and, except for Venus and Mars, have stratospheric temperature inversions as well. The former implies heating from below, whereas the latter requires heating from above. Two external heating sources are therefore required. Although the opacity in real atmospheres is extremely variable with wavenumber, the essential physics can be distilled by treating the opacity as independent of wavenumber over each of three large spectral intervals, or channels. 

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