[en] On the base of all positional observations which were published till the end of 1982 the new osculating orbits of the following minor planets: (457) Alleghenia, (649) Josefa, (1038) Tuckia, (1161) Thessalia, (1162) Larissa and (1297) Quadea have been obtained. In the process of orbit improvement three new factors are taken into account. The use of greater number of observations in the longer time intervals, the selection and weighting of observations and including secular changes of the orbital semi-major axis to the model of asteroidal motion are leading up to the better determination of orbits of the discussed minor planets than formerly. This made possible an examination of the general opinion that the motion of asteroids is free from such nongravitational effects as observed in a cometary motion. The computed values of daily changes of the semi-major axis do not confirm this conjecture. The comparatively well determinable secular deceleration in the motion of (1161) Thessalia has been discovered. The comparison of results received up to now by me and concerning the mentioned minor planets orbits is presented. 11 refs., 4 tabs. (author)

[en] Data on the Halley comet nucleus obtained at Vega and Jotto space probes flight near it, allow to conclude, that the nucleus was formed in the preplanetary nebula, probably near nuclei of Uranus or Saturn (less probable - near nucleus of Neptune)

[en] The problem of planet and satellite production is discussed. Investigations of processes in near the Sun and near the planet disks are the basis of modern approaches to the problem. The efforts of researchers are concentrated on detailed development of evolution scenario for small-mass weak-turbulence gas-dust disk. Investigation of dynamic evolution of near the Sun cluster of bodies are intensively developed in some research groups in USA, Japan, France, FRG and other countries. The theory of mass spectrum and body velocities in the cluster is plotted

[en] A wide variety of experiments can be conducted on the Space Station that involve the physics of small particles of planetary significance. Processes of interest include nucleation and condensation of particles from a gas, aggregation of small particles into larger ones, and low velocity collisions of particles. All of these processes could be investigated with a general purpose facility on the Space Station. The microgravity environment would be necessary to perform many experiments, as they generally require that particles be suspended for periods substantially longer than are practical at 1 g. Only experiments relevant to planetary processes will be discussed in detail here, but it is important to stress that a particle facility will be useful to a wide variety of scientific disciplines, and can be used to address many scientific problems

[en] The origin of the Moon by a single massive impact of a body slightly larger than Mars with the Earth can explain the angular momentum, orbital characteristics and unique nature of the Earth-Moon system. The density and chemical differences between the Earth and the Moon are accounted for by deriving the Moon from the mantle of the impactor. A cosmochemically plausible impactor can be formed in the region of the inner Solar System, lending support to the impact hypothesis. (author)

[en] A method for reconstructing the Earth dipole magnetic moment in the past based on data analysis on cosmogenic isotope content (¹⁰Be and ¹⁴C) in earth samples is proposed. The results on geomagnetic field value for the last 9 thousand years are determined and compared with the archaeomagnetic data. The time dependence of the Earth dipole magnetic moment during the geomagnetic inversion period is reconstructed

[en] Searches for absorption features of HD near 6050 A are reported for Uranus and Neptune. The existence of blends of the HD features with weak features due to minor species in the atmosphere of Uranus is demonstrated. These blends make the unambiguous identification of the weak HD features exceedingly difficult. The data are analyzed with inhomogeneous scattering models to ascertain a D/H upper limit for Uranus and Neptune of 0.0001, a factor of 2 smaller than the upper limit reported from CH3D measurements. 21 references

[en] The abundances of chromium isotopes, in refractory inclusions from the Allende meteorite, show wide-spread anomalies. The chromium isotope anomalies are similar in pattern to the anomalies discovered in calcium and titanium. The largest effects occur at the neutron-rich isotopes ⁴⁸Ca, ⁵⁰Ti and ⁵⁴Cr. Individual Cr-rich pink spinels, from the Murchison meteorite, exhibit large and variable excesses in ⁵³Cr and ⁵⁴Cr, including the largest ⁵³Cr anomaly so far reported (δ(⁵³Cr/⁵²Cr)=3.2±0.6%). Magnesium isotopes, in Murchison Cr-poor blue spinels, also show variable anomalies in ²⁶Mg including mass-dependent fractionation favoring the lighter isotopes. The ^53,54Cr and ²⁶Mg anomalies in Murchison spinels are indicative of a heterogeneous distribution of magnesium and chromium isotopes in the early solar nebula and require a contribution from several nucleosynthetic components in addition to physicochemical processing. (orig.)

[en] Monticello is a new howardite similar to Malvern in that it contains abundant (15 percent) glass fragments, which show a range of compositions from olivine-normative to quartz-normative. Like Kapoeta, it contains pyroxene grains that range up to highly magnesian compositions, Fs16. Because their pyroxenes are more magnesian than those occurring in diogenites, Monticello and Kapoeta are exceptions to the simple two-component mixing model in which howardites are considered to be mechanical mixtures of fragmented eucrites and diogenites. Monticello also contains clasts of what appear to be a cumulate eucrite and a noncumulate eucrite, as well as a radiating pyroxene chondrule from a chondrite. Monticello is a regolith breccia containing more evolved components than are usually considered in eucrite-diogenite genesis models. As such, it supports those models that involve reworking of a complex parent body crust rather than straightforward partial melting of primitive chondritic parent material. 37 references

[en] Near IR photometric observations of Comet Halley obtained at the Cerro Tololo Inter-American Observatory in 1985 are presented and examined. It is observed that (K-L) is affected by thermal emission; for heliocentric distances greater than about 2 AU; (J-H) and (H-K) are significantly redder than normally found in comets; and as the heliocentric distance decreases Halley is bluer and has more usual color. The scattering cross-sectional area of the coma within the field of view and the reduced J, K, H, and L magnitudes for the comet are calculated. The data reveal that in each line the reflectivity increases from J to K band and J and H scattering efficiency increases as the comet approaches the sun. 11 references