An international team of scientists, which included experts from the United States and France, explained the results of a study carried out in the atmosphere of Venus by the Soviet station "Vega-2". The researchers shared their findings in the journal Nature Geoscience.
The sharp changes in temperature on Venus, recorded by the Soviet station "Vega-2" at an altitude below 7 kilometers from the surface of the planet, scientists explained by a change in the chemical composition of the layers of the gas envelope. The reasons why such conditions exist in the atmosphere of Venus were not previously known to researchers.
Nitrogen and carbon dioxide predominate in the gas shell of this planet, and the concentration of the former, according to the authors of the study, begins to drop sharply starting from an altitude of about 7 kilometers. Starting from 12 kilometers at a pressure of 75 bar and temperatures of 700 Kelvin, matter in the atmosphere of a celestial body behaves like a supercritical fluid.
Scientists do not yet know why the nitrogen content near the surface of Venus begins to decline sharply. They consider convection to be one of the explanations for this trend. If the hypothesis of the researchers is correct, then the nitrogen content in the gas envelope of the planet is 15% lower than previously thought. The authors of the study came to such conclusions in the course of theoretical calculations, as well as experimental modeling of the conditions of the atmosphere of a celestial body.
Recall that the Soviet interplanetary station "Vega-2" explored the second planet in the distance from the Sun in 1985. The mission to Venus, which consisted of a flight vehicle and a descent probe, was deemed successful.