Any two bodies affect each other with mutual attraction that depends on their masses and the distance between them. The space around them contains the so-called Lagrange points in which their gravitational pulls cancel each other. If a third body is placed in such a point, it will remain fixed against the other two or move along the orbit with one of them. This theoretical fact is confirmed by astronomic reality: groups of asteroids moving around the Sun together with Jupiter were discovered around the Lagrange points of the Sun-Jupiter system. The same should supposedly be observed in the Earth-Moon system, however, in this case the gravitational pull of the Sun should be taken into consideration as well.
The first positive experimental proof of the existence of dust clouds in the Lagrange points of the Earth-Moon system were obtained in October 2018. A RUDN mathematician carried out a theoretical study that confirmed the results of the observations.
“The Lagrange points are stable in the Sun-Jupiter, Sun-Earth, and Earth-Moon systems. It is only natural to expect that certain cosmic mass shall accumulate in them. However, the fundamental difference between the Lagrange points in the Earth-Moon and the Sun-Jupiter systems lies in the major gravitational pull of the Sun that should be taken into consideration,” said Tatiana Salnikova, a co-author of the work, a Candidate of Physics and Mathematics, and a research associate at the Institute of Space Technologies, RUDN.
According to the suggested model, each particle has its own charge and oscillates in the vicinity of a Lagrange point thereby creating its own electrical field. RUDN mathematicians studied a system of equations for a random number of such particles in the external gravitational field. The obtained numerical model of the dust clouds coincide with experimental observations made in 2018. Before that, the scientists had been denying the existence of Kordylewski clouds (named after the Polish scientist Kazimierz Kordylewski who was the first to suggest their existence in 1956). None of numerous space missions was able to give a clear confirmation of the hypothesis.
“Our numerical modeling results perfectly correlate with earlier observations. We can now be sure that Kordylewski clouds do exist. Therefore, they should be taken into consideration when planning space missions,” added Tatiana Salnikova.
The participants of the study also represented Lomonosov Moscow State University.
RUDN soil scientists have revealed a direct correlation between the rate of soil formation of carbon dioxide, called CO2 emissions, and the content of microbial biomass in it. It is known that CO2 emission from soil is mainly conditioned by respiration of soil microorganisms and plant roots. The more CO2 soil emits, the more microbial biomass it usually contains. It was shown that CO2 emission by chernozem of different ecosystems (or different types of land use) correlates with the content of microbial biomass, and most closely with the rate of its microbial respiration. And the soil with good microbial properties has the “best quality”, is more fertile, provides the highest yield of crops and other plant biomass.
A RUDN chemist has synthesized a catalyst for the production of gamma-valerolactone — an energy-intensive “green” biofuel. The catalyst based on zirconium dioxide and zeolite has shown high efficiency in converting the waste of wood plant materials — methyl levulinate — to gamma-valerolactone.
Biochemists from RUDN University determined which substances in peach leaves provide the antioxidant effect their extract has. They investigated the composition of the powders obtained from leaves of several varieties of peach and found that high polyphenol content correlates with antioxidant properties. The results will help start production of antioxidants from natural sources.