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[en] In the recent years, the 'Nice' model of solar system formation has attained an unprecedented level of success in reproducing much of the observed orbital architecture of the solar system by evolving the planets to their current locations from a more compact configuration. Within the context of this model, the formation of the classical Kuiper Belt requires a phase during which the ice giants have a high eccentricity. An outstanding question of this model is the initial configuration from which the solar system started out. Recent work has shown that multi-resonant initial conditions can serve as good candidates, as they naturally prevent vigorous type-II migration. In this paper, we use analytical arguments, as well as self-consistent numerical N-body simulations to identify fully resonant initial conditions, whose dynamical evolution is characterized by an eccentric phase of the ice giants, as well as planetary scattering. We find a total of eight such initial conditions. Four of these primordial states are compatible with the canonical 'Nice' model, while the others imply slightly different evolutions. The results presented here should prove useful in further development of a comprehensive model for solar system formation.
[en] We have obtained a full suite of Spitzer observations to characterize the debris disk around HR 8799 and to explore how its properties are related to the recently discovered set of three massive planets orbiting the star. We distinguish three components to the debris system: (1) warm dust (T ∼ 150 K) orbiting within the innermost planet; (2) a broad zone of cold dust (T ∼ 45 K) with a sharp inner edge orbiting just outside the outermost planet and presumably sculpted by it; and (3) a dramatic halo of small grains originating in the cold dust component. The high level of dynamical activity implied by this halo may arise due to enhanced gravitational stirring by the massive planets. The relatively young age of HR 8799 places it in an important early stage of development and may provide some help in understanding the interaction of planets and planetary debris, an important process in the evolution of our own solar system.
[en] The problem of Solar system origin is discussed within the framework of the model of the Sun and protoplanet disk formation in the case of protoplanet cloud compression. During compression cloud density in its centre increases faster than at the edge which results in the separation of a nucleus with the mass equalling 1% cloud mass. After nucleus formation from its outer layers,a disk starts to form. The above mechanism of protoplanet disk formation does not contradict the data obtained in the course of studying meteorites and Halleys comet
[en] Estimates of the size distribution of Main Belt asteroids suggest that there is an undetected population of approximately 10 trillion objects in the meter-to kilometer-range. These small objects are highly diverse impact generated fragments of ancient asteroids. This vast and so far unexplored resource of small bodies holds a rich variety of information on the origin and evolution of our Solar System. Current Earth-based telescopes have, with a few exceptions, not been able to detect the faint and distant meter-sized asteroids in the Main Belt. Deep exposures cannot be used, unless the object can be tracked, which is not possible for an object in an unknown orbit. Small asteroids can be observed close up from a spacecraft but, so far, missions to the Main Belt have not had the ability to detect new small asteroids (with the exception of Dactyl, the kilometer-sized asteroid, that was found orbiting the much larger asteroid Ida). Due to the rapidly changing geometry, small asteroids can only be observed from a spacecraft for a very limited time, hence it is not possible to operate a spacecraft from the distant Earth and a fully autonomous mission is required. The technology required to build such spacecrafts does exist and has been tested in space. We have explored the scientific potential of deep space missions to detect and study small asteroids from spacecrafts traveling through the asteroid Main Belt
[en] The origin of the smaller solar-system objects is investigated theoretically, extending and refining the hypothesis put forward by Vorontsov-Vel'iaminov (1982). It is proposed that virtually all asteroids and cometary nuclei, as well as many planetary satellites, are fragments from the explosion of a major planet called Asteron
[en] For various practical reasons it is necessary to reduce solar-system investigations into component parts, both in space and time. Thus we speak of lunar science, meteor astronomy, the study of Jupiter, and meteoritics, as if they were separate sciences. Similarly, the accumulation of the planets, their early heavy bombardment history and the present interplanetary flux of cratering projectiles are usually discussed separately. In doing so it is easy to lose sight of the fact that the solar system is a system and our understanding of individual bodies and events must be fitted together in a harmonious way. The present paper represents a limited attempt to accomplish a small part of this task. I will try to trace a plausible course of events for the history of the residual bodies which remained in the inner solar system at the time when the accumulation of the Earth and Venus was nearly complete. This discussion is not intended to be in any way a definitive treatment of this subject. Rather it is meant as an example of the possibilities for integrated treatments of solar-system processes in time and space. (orig./WL)
[en] The current concepts of the origin and evolution of the Solar System are discussed, and some notions about extrasolar planets are reviewed. The present status of and future prospects for space exploration in Russia and abroad are examined. (conferences and symposia)
[en] The problem of the Solar System stability as defined by Laplace and Lagrange in the second half of the 18th century, in celestial mechanics appears as Lagrange's theorem. This article is an attempt to present up-to-date knowledge about the Solar System stability. (author)