Russian scientists reproduced in the laboratory the trail of a fireball, an optical phenomenon that occurs when a large celestial body burns up in the atmosphere, and were able to determine its key parameters. This will improve the existing fireball motion models, which will make the development of asteroid hazard protection systems more efficient, and will also help in the study of other planets. The results of the study, supported by a grant from the Russian Science Foundation, were published in the journal Astronomy & Astrophysics.
When a celestial body of artificial or natural origin enters the Earth’s atmosphere, it immediately begins to burn. This phenomenon is known as “shooting stars”, or meteors, which are the glow of a cloud of heated gas (plasma) and solid particles that are separated from a hot cosmic body. If a meteor is very bright—brighter than Venus—it is called a fireball.
Specialists build models of how a falling object will move in the atmosphere in order to calculate where a space object (for example, a meteorite) will fall and whether it will reach the Earth’s surface at all. Also, these calculations are useful when considering the problem of asteroid hazard for developing measures to protect against collisions with large cosmic bodies. To make the calculations more accurate, it is necessary to have an idea of what happens to them in the process of falling, how their temperature and pressure change in the meteoroid trace. There are several models that allow you to calculate how the body will move, but not all characteristics can be obtained mathematically, and as a result, scientists work with their approximate values. Moreover, numerical simulation is not always possible, and in this case, one can proceed to recreate the process of meteoroid combustion in the laboratory.
Employees of the Moscow State University named after M. V. Lomonosov reproduced in the laboratory the track of the fireball. The authors directed a powerful laser beam at a target made of iron oxide – this metal is often found in meteorites and materials from which aircraft are made, and the oxide is formed when iron interacts with atmospheric oxygen. They then observed how the emission spectrum of this compound changed when it was evaporated at high temperatures.
Scientists have found that the temperature in the cooling track of the car reaches 4,700 ° C. From the emission spectra of iron, they also calculated that the pressure in it exceeds atmospheric pressure by 25 times. The results of the study are of practical importance in the study of asteroid hazard, de-orbiting satellites or space debris, as well as the features of the destruction of bodies upon entry into the Earth’s atmosphere. Based on the characteristics of the motion of the fireball, it is possible to calculate its trajectory before the collision with the Earth, which helps to determine the origin of the cosmic body. In addition, the exact trajectory of the object’s movement makes it possible to predict the place of its possible fall.
“We hope that in the future we will be able to expand our model with the participation of Russian and foreign colleagues. In the meantime, we plan to apply it to simulate the entry of various celestial bodies into the atmosphere. Moreover, by studying meteor phenomena around other planets and satellites, such as Mercury, Venus or the satellites of Jupiter, you can learn more about them,” says Timur Labutin, the project sponsor, supported by a grant from the Russian Science Foundation, Candidate of Chemical Sciences, Associate Professor of the Department of Laser Chemistry, Faculty of Chemistry Moscow State University.