On the periodic variations of secondary cosmic rays and the geomagnetic Pc4 pulsations in BMAr

In a set of balloon flights in the Brazilian magnetic anomaly region (BMAr) short time periodic variations were observed, i.e. pulsation, of secondary charged and neutral particle fluxes, X- and -ray fluxes with amplitudes of about 2–4%. The pulsations are accompanied by the geomagnetic Pc4 pulsations and have similar periodicity. The phenomenon was observed over various local times and in quiet and disturbed magnetospheric conditions. One of the explanations of this effect, i.e. periodic variation of local cut-off rigidity, and following pulsations of primary and secondary cosmic ray intensity is suggested.     

Structure of the South Pole-Aitken lunar basin

The hypsometric map and the basin height profiles, for the first time relying upon a spherical daturence surface, have been constructed based on the generalization of the heights measured within the hemisphere including the ring structure of the South Pole-Aitken basin. The distribution of the major chemical elements (Fe and Th), depending upon the structure height levels, has been obtained. The relationship between these lunar rock indicators and the height levels of the rock preferential distribution has been revealed. The outer basin ring has been distinguished and the ring structure of the central basin depression has been revealed against a combined hypsometric and geochemical background. A total basin diameter of about 3500 km has been reliably determined for the first time. A unique feature of the basin structure consists in that the arrangement of the basin inner rings does not show a central circular symmetry, which can indicate that a hypothetical impactor moved along the trajectory (or orbit) oriented almost normally to the ecliptic plane. In combination with the revealed very small depth-diameter ratio in the initial basin structure, this circumstance makes it possible to put forward the hypothesis that a comet impact produced the South Pole-Aitken basin.     

Hydrogen and helium isotope inner radiation belts in the Earth’s magnetosphere

Radial transport theory for inner radiation zone MeV ions has been extended by combining radial diffusive transport and losses due to Coulomb friction with local generation of D, T and ³He ions from nuclear reactions taking place on the inner edge of the inner radiation zone. Based on interactions between high energy trapped protons and upper atmospheric constituents we have included a nuclear reaction yield D, T and ³He flux source that was numerically derived from a nuclear reaction model code originally developed at the Institute of Nuclear Researches in Moscow, Russia. Magnetospheric transport computations have been made covering the L-shell range L=1.0–1.6. The resulting MeV energy D, T and ³He ion flux distributions show a strong influence of the local nuclear source mechanism on the inner zone energetic D, T and ³He ion content.     

The formation of high energy electron fluxes in the inner radiation belt of earth

Measurements on board the low altitude polar orbiting satellite Intercosmos-17 /nearly circular orbit h = 500 km, i = 83.5°/ have shown relatively high fluxes of high energy electrons /E_e > 100 MeV and E_e > 300 MeV respeetively/ at minimum-B-equator. Computation of the electron production spectra assuming the interaction of high energy protons of the inner radiation belt with residual atmosphere is made. The considered mechanism can explain the enhanced flux of high energy electrons registered in the Brazil magnetic anomaly.     

Photometric relief of the previously uninvestigated surface of mercury

The results of investigations of the surface relief of Mercury with a classical photometric method are reported. A subject of the photometric method is the intensity of light reflected by the surface of the planet. The main data for the photometric study are the high-resolution images of Mercury received from the MESSENGER space station during its first flyby over Mercury. The images of the surface of Mercury were downloaded from the NASA web-site (http://messenger.jhuapl.edu) and converted to a digital form for photometric measurements. The reflectance characteristics of the surface were calculated according to the model of a three-dimensional scattering phase function (Shevchenko, 1979; 2004a; 2006). From the photometric processing of the space-borne images, the reflectance of four morphologic types of the surface structure of Mercury was determined. With the Hapke model of the bidirectional reflectance (Hapke, 2001), the structural inhomogeneity of the regions of the morphologic forms with centimeter-sized rough-ness was estimated.     

Geological-Geophysical Investigations in the North Atlantic during Cruise 53 of the R/V Akademik Sergey Vavilov

Oceanology - We provide information on geological and geophysical investigations of the structure of the area between the Bight and Charlie Gibbs transform faults in the North Atlantic during...     

The Spatial Angular Function of Thermal Emission of the Moon

New satellite measurements of the lunar-surface radiation temperature are used to construct the spatial angular function of thermal radiation of the Moon in the infrared (10.5–12.5 m) spectral range. The basic material for investigations is the scanned cosmic spectrozonal images of the lunar surface transmitted by the first Russian geostationary artificial meteorological satellite GOMS. The formulas for calculating the angular parameters are given, and the photometric function of thermal radiation of the Moon is plotted as a function of the incidence angle, the reflection angle, and the azimuthal angle between the planes of the incident and reflected rays.     

The Temperature Regime of the Proposed Landing Sites for the Luna-Glob Mission in the South Polar Region of the Moon

In this paper we consider a hydrodynamic model for the matter density distribution in a self gravitating, isentropic 2-d disk of gas where the isentropy coefficient is allowed to be a function of position. For this model we prove analytically the existence of steady state and time dependent solutions in which the matter density in the disk is oscillatory and pattern forming. This research is motivated in part by recent astronomical observations and Laplace conjecture (made in 1796) that planetary systems evolve from a family of isolated rings that are formed within a primitive interstellar gas cloud.