The aim of this paper is the determination of six orbital elements if two positions (1 and 2) of a solar system body are known. The task was solved using the ratio of the elliptical sector to the area of the corresponding triangle. This relationship was labelled as η and derived by K. F. Gauss (1809), see sections 1 and 2. This paper presents four easy methods that supply the ratio, see section 3. These methods simplify this task by removing long and very complicated derivations and by clarifying the theory and calculations. The methods are not used in the case of more than two observations., Josef Kabeláč., and Obsahuje bibliografii
In celestial mechanics interactions of radiation and small bodies in Solar system can be classified as scattering, absorption, radiation drag and thermal emission. The final one, in particular, induces important secular changes of orbits and rotation states of asteroids and meteoroids, as supported by a number of astronomical observations., Miroslav Brož., and Obsahuje seznam literatury