Scientists Discovered Why The Planets Of The Solar System Contain A Lot Of Iron And Magnesium
An international team of researchers using computer simulations has determined the reason why the planets of the Solar system are dominated by heavy chemical elements-iron and magnesium, according to the press service of the Siberian Federal University (SFU).
According to existing scientific theories, the planets of the Solar system appeared from a gas-dust cloud. First, the so-called "germs" of planets (protoplanets) were formed, then the largest of them attracted and absorbed their neighbors, after which they formed their final form-such, in particular, was the "childhood" of the Earth.
The authors of the new study, which included Professor of the Department of applied mechanics of SFU, chief researcher of the Institute of computational modeling SB RAS Nikolai Yerkaev, using computer modeling identified the process that causes the planet to lose light chemical elements at the stage of formation of the "embryo" of the planet. This leaves heavy elements such as iron and magnesium at its core.
"Planetary" embryos "due to mutual collisions, gravitational energy, and heating form oceans of incandescent magma. As a result of this process, volatile elements are released, and vapor atmospheres are formed. However, during the solidification of magma, the vapor atmosphere evaporates and can completely disappear under the influence of Solar radiation. Scientists have studied this mechanism on the example of a young star and found out that" escaping "hydrogen atoms can pull from the surface of the planet not only light but also such massive elements as neon, argon, as well as potassium, sodium, silicon and magnesium," the press service said.
Scientists have concluded that the intense loss of light chemical elements, in particular, depends on the mass of the forming planets. In planetary embryos with a mass less than the moon, gravity is too weak to form a dense vapor atmosphere. As a result, all the light elements evaporating from the surface of the planet escape into outer space, the authors explain. Distance from the Sun also plays an important role – for example, a protoplanet with a mass less than Mars will quickly lose its vapor atmosphere with its trace elements if it is located at an orbital distance of 1.5 astronomical units from the Sun.
"Finally, for all the considered planetary masses and orbits, the intensity of "leakage" of argon and neon is so high that there will be no separation of their isotopes in the atmosphere. It can be concluded that the studied planetary embryos, even in the absence of isotope separation, will be severely depleted of inert gases and moderately volatile elements. Thus, the hydrodynamic outflow of atmospheres can significantly affect the final composition of planets that absorb such planetary embryos in the course of their evolution, and this can concern both the volatile components and the ratio of iron and magnesium in the composition of the planet. The mechanism considered may be one of the reasons for the high values of iron and magnesium and low values of silicon observed on Earth at present, " the press service of the SFU quotes Nikolay Yerkaev as saying.
The research also involved researchers From the Institute for space research of the Austrian Academy of Sciences and the Karl and Franz University of Graz (Graz, Austria), as well as the University of Versailles-Saint-Quentin-EN-Yvelines (Versailles, France). The results are available in the Icarus journal.