Russian Journal of Astrophysical Research. Series A

17-26

Authors: Vladimir P. Kulagin

The article explores the problem of comet hazard. This problem is isolated from the problem of asteroid-comet hazard due to essential features. Features comets are described in the article. The classification of comets is given in the work. The article analyzes the origin of comets. The structure of the comet is investigated in the aspect of the object that poses a threat in collision with the Earth. As an example, four famous comets are considered. The article reveals the content of the information approach to the study of the problem of comet hazard. The article identifies the main objectives of the information approach: informational description of comets, dynamic modeling of the behavior of comets, forecasting the situation with a comet, cataloging dangerous space bodies.

34-40

Authors: Vladimir V. Oznamets, Viktor Ya. Tsvetkov

The article explores the features of the use of space geodesy in the description of small celestial bodies. The paper shows the difference between geodesic astronomy and space geodesy. The paper shows the difference between ground geodesy, astronomy and space geodesy. The main stages of cartographic modeling are described. Cartographic modeling of space bodies or space mapping includes three stages. The first stage transforms the original cosmic body into a reference geometric body. The reference geometric body is transformed at the second stage into a geometric figure having a scan. The geometric shape is converted to a flat scan in the third stage. Conformal transformations are the basis for the implementation of the second and third stages. Problems appear at the first stage of spatial transformations. The irregularity of the cosmic body creates significant distortions in the construction of its surface. The authors of the article propose geodetic modeling and geodesic constructions as an alternative. Geodesic space modeling is a generalization of geodetic and photogrammetric measurements. For small space those use photogrammetric measurement methods. Geodesic modeling allows you to create a three-dimensional triangulation model. The article confirms the conclusion that geometry, geodesy and geoinformatics are applicable for the study of space bodies.