Venus hydrogen escape

The oxidation of Fe " "-bearing minerals in basalt (and other volcanic rocks on Venus surface) is potentially very important for water loss via oxidation of the surface and hydrogen escape to space. The overall process is schematically represented by... 

On Venus, hydrogen atoms with sufficient energy to escape the gravitational attraction of the planet are produced in the reactions... 

Hydrogen isotopes have also been fractionated during planetary geologic processes. Compared to the Earth, Venus and Mars have significantly elevated D/H ratios (5D = 125 000 permil and 4000 permil, respectively). These fractionations are thought to result from preferential loss of H relative to D from the atmospheres of these planets (Robert el al., 2000) atmospheric escape of hydrogen from the Earth was apparently not important. 

The energetics of the ionospheric reactions are critical to the escape of nitrogen from Mars and of oxygen and hydrogen from Venus. 

Vertical distributions of the molecular density and mixing ratios of H2O and HDO in the Venus mesosphere were measured by Fedorova et al., 2008 [129]. The experiment was carried out on board of Venus express mission (SOIR instrument, 2.32-4.35 pm). The atmosphere was sounded during solar occultation in the range of altitudes from 65 to 130 km. An enrichment of D to hydrogen indicates the escape of water from Venus. Bertaux et al., 2007 [25] report on the detection of a warm layer at 90-120 km. ... 

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