Dusty dust: particles from space can help find traces of interstellar comets

Russia has proposed a method that will help find traces of interstellar comets. The method is based on the study of space dust settling on the Earth. In these microparticles, scientists find structures that are not typical for objects of the solar system. In particular, such compounds were found during the study of space particles in the trace of the Chulym cosmic body, an object that exploded in the atmosphere at an altitude of about 100 kilometers in the vicinity of the Chulym River on the border in the Tomsk region.

How space dust particles are determined

Scientists from the Institute of Earth Physics of the Russian Academy of Sciences have developed a method for identifying objects whose place of origin is outside the solar system. The method is based on the study of space dust. Every day about 54 tons of such particles fall to the surface of our planet. Therefore, experts consider this substance to be one of the most significant sources of information about the cosmos.

Photo: RIA Novosti/Maxim Bogodvid

- Extraterrestrial dust particles differ both in type and place of formation. For example, there are background particles that arose as a result of the destruction of asteroids and comets. They were captured by the gravity of our planet and are present in its atmosphere as a constant component. There are also "splash" particles, which were formed as a result of an explosion or ablation (blowing off the surface of a solid body) when space objects enter the dense layers of the Earth's gas shell, - told "Izvestia" one of the authors of the proposed methodology, a leading researcher at the Geophysical Observatory "Borok" - a branch of IFZ RAS Vladimir Celmovich.

According to him, the background particles of asteroidal origin have a solid and dense structure, and cometary - more loose and porous. Their pores often contain ice. It is also found that the velocity of cometary particles on entering the atmosphere is lower than that of asteroidal particles, so they are less susceptible to transformation.

Magnetite microspheres on carbon substrate

Photo: provided by Vladimir Celmovich

In addition, cosmic dust particles, which are produced by the explosions and ablation of bolides in the atmosphere, are subjected to extreme impacts. Such particles may contain microcracks, molten veins, gas bubbles and other disturbances in the structure.

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As explained Vladimir Celmovich, the study of the features of dust can tell us what type of space objects belong to. For example, this method scientists applied in the study of the area near the river Chulym in the Tomsk region, where in 1984 observed a space body, which with a strong explosion collapsed at an altitude of about 100 km. So in the moss in the zone of the bolide's passage, experts found particles that show the possible cometary origin of the object. Similar findings were made in the places of the fall of Tunguska (1908) and Uchursky (1993) space bodies.

Which points to other star systems

According to the scientist, further development of the method can be associated with the identification of objects that came from outside the solar system. The assumption is based on the discovery of European astrophysicists, who found spectral lines of pure nickel and iron in the plume of comet Borisov.

- Previously, when studying samples that belong to the Chulym cosmic body, our group discovered micron-thick nickel films sputtered on various surfaces. In this case, pure nickel cannot be formed in the Earth's crust. Then this fact was simply recorded by our group in the relevant scientific articles. However, after the publication of the results of the work of European colleagues, we suggested that these events may be related and nickel films may represent traces of such objects, - said Vladimir Celmovich.

Magnetic micrometeorites

Photo: Provided by Vladimir Celmovich

He explained that Comet Borisov was the first ever interstellar object discovered by scientists. It was discovered by Russian astronomer Gennady Borisov on August 30, 2019. Since then, a number of other comets have been found that may fall into the same category. Perhaps analyzing the composition of space dust will help to identify such objects more accurately.

According to Vladimir Celmovich, the study of compounds that formed outside the solar system also has practical applications. In particular, such findings will prompt scientists materials for future space metallurgy. Including those that can withstand interstellar travel.

- Reliability of modern methods of determining interstellar objects at the moment - low, but these technologies are rapidly developing and the results of research are becoming more and more confident. For example, very high sensitivity of modern space chromatographs - devices that can determine the chemical composition of celestial bodies on the lines of the spectrum - shared his thoughts with "Izvestia" leading researcher of the Institute of Space Studies of the Russian Academy of Sciences Nathan Eismont.

Fe-Ni alloy particles, micrometeorites

Photo: Provided by Vladimir Celmovich

He noted that the study of space dust is a promising method. At the same time, it is more informative to study the particles that did not get into the Earth's atmosphere. For example, the dust that settles on the Moon. In addition, any vehicle that is sent into space is equipped with instruments that, to a greater or lesser extent, allow you to study microparticles. However, their study on Earth is much cheaper.

- Space dust covers the surface of the planet in an even layer. Usually, this material is well preserved in the zone of eternal glaciers and deserts, where it is most promising to take samples. At the same time, microcosmic material has a significant difference from modern anthropogenic dust - both in composition and forms of release. In addition, in their methods scientists use magnetic properties of the material, - emphasized Associate Professor of the Department of Geography of Oceans of the Lomonosov Moscow State University Branch in Sevastopol Vitaly Lysenko.

Therefore, in his opinion, the study of space dust may not be limited to isolated areas of the earth. At the same time, Russian scientists have made significant progress in this direction. The expert is sure that the study of messengers from space helps to better understand the history of the formation of the Earth and life processes on it.