Cosmonautics Day – after 200 years of space and planetary research Kazan Federal University still among the leaders of the field

The Cosmonautics Day has been celebrated in Russia since 1968 to celebrate the first manned spaceflight by Yury Gagarin which took place on 12 April 1961.

Yury Nefedyev, Director of KFU Engelhardt Observatory, talks about the alma mater’s achievements in astronomy and space science.

The Astronomy Department of Kazan Imperial University (now the Department of Astronomy and Space Geodesy of KFU) is the oldest in Russia. Professional astronomers have been trained here since 1810. Among the first students of the department were Nikolay Lobachevsky and Ivan Simonov, two famed scholars and rectors of the University. In 1838, an observatory was built in the central campus. For example, Professor Marian Kowalski (since 1854 he was head of the Kazan University Observatory) suggested that our star system was spinning. In 1899, the observatory was moved to the north of the city to avoid light pollutuion. The new observatory was named after Vasily Engelhardt. As of now, it is poised to be part of the UNESCO World Heritage List.

KFU is one of the leading Russian and world centers in astronomy and space geodesy, both in professional education and research.

The scientific data obtained by Kazanian astronomers has been used in the preparations of launches for the Moon and Mars. In this regard, the work on selenodesy and meteor astronomy is particularly noteworthy. In the field of selenodesia, five heliometric rows were observed to bind the crater Mesting A to determine the permanent physical libration of the moon (FL) and to study its shape (A.V. Krasnov, T. Banakhevich, A.A. Yakovkin, I.V. Belkovich, A.A. Nefedyev). According to heliometric observations of crater Mesting A, maps of the edge zone of the Moon (A.A. Nepediev) have been constructed. The horizontal telescope also contains a photographic series of observations of the Moon for the purpose of studying FLU (S.T. Habibullin). 435 images of the Moon against the background of the stars in order to establish a uniform scale of ephemeris time were obtained by N.G. Rizvanov. A unique method of obtaining large-scale images of the Moon against the background of stars has been developed, on the basis of which a number of selenodesia problems have been solved by the absolute method (N.G. Rizvanov, S.G. Valeev). For the first time, the center of mass of the Moon was proved to be 3.3 km closer to the Earth than the center of its figure (K.S. Shakirov). The subtle effects of physical libration in the rotation of the Moon related to the presence of the multilayer core have been studied, the theory has been developed and for the first time estimations of periods of possible free librations and free nutrition of external liquid and solid inner core (N.K. Petrov, A.A. Zagidullin) have been made. A global catalogue of supporting objects in the celestial coordinate system (Y.A. Nefedyev, N.Y. Demina, A.O. Andreev) has been built.

Kazan University scientists have also carried out a number of significant works in meteor astronomy. For instance, the statistical theory of radar of ionized meteor trails has been developed taking into account the random position of the reflecting point on the track, its initial radius and diffusion during its formation (by mathematical modeling – K.V. Kostylev, by analytical method – O.I. Belkovich). In addition, a method has been developed for calculating the density distributions of sporadic meteor bodies on the celestial sphere, based on observations of meteor traces on a rotating antenna radar (Y.A. Pupyshev, O.I. Belkovich). Astronomical bases of meteor radio communication (K.V. Kostylev, O.I. Belkovich), methods of processing radar and visual observations of meteor streams in order to study variation of meteor body density with mass above 10^-3 degree r and the parameter s of their mass distribution along the Earth’s orbit as a function of the longitude of the Sun have also been developed. This made it possible for the first time to obtain the evolution of meteor flows Perseids and Leonids at an observation interval of 160 years (O.I. Belkovich, N.I. Suleymanov, V.S. Tokhtasiev, M.G. Sokolova, S.V. Suleymanova, M.V. Sergienko).

In addition, the formula for transforming the flux density of sporadic meteoroid bodies in the gravitational field of a moving body (O.I. Belkovich, V.V. Andreev) has been derived, the basics of GOST (national standard) for meteor substance and its spatial distribution have been developed. The GOST is used to calculate the reliability of human and technical devices on the spacecraft (O.I. Belkovich). It has also been shown that the gravitational focus of the Sun increases the flux density of interstellar meteor bodies with a radiant in the antiapex of the Sun by a million times (O.I. Belkovich).

In the past few years, the Lunar Mission Navigation Support System has been developed and the task of establishing a navigation simulation model for the anchoring of the Lunar Space Satellite has been completed to dynamic selenocentric reference system based on coordinate transformation using regression modeling. For the first time in the world, based on the coordinates of the lunar object observed by the LSs and using software developed by the authors, now it is possible to calculate and compare the parameters of altimetry of this point in relation to selenocentric digital map of the Moon surface.

Also within the framework of the grant «Creation of dynamic simulation selenographic model with consideration of parameters of internal structure of the Moon on the basis of methods of space geodesy, planetary science and multiparametric analysis» a numerical theory of physical libration of the Moon (FLP) was constructed – which is one of the main tools in studying the inner structure of the Moon, as well as the basis for solving the problems of selenodesy and coordinate-time support.

As a result, numerical tables for application in practice for two models are obtained: solid-state moon models taking into account the 3rd and 4th harmonics in the decomposition of selenopotential and for the model of elastic Moon using the method of average moments of inertia. All these results were included in the list of the most important scientific achievements by the decision of the Scientific Council of Astronomy of the Russian Academy of Sciences in 2021. It is planned that they will also be used for future Russian lunar missions.