Optical properties of the undisturbed mesosphere from wide-angle twilight sky polarimetry

The paper describes the first results of all-sky polarization measurements of the twilight background started in central Russia in the very beginning of summer 2011. Time-frequency data of the sky intensity and polarization over a wide range of sky point zenith distances are used to separate single and multiple scattering and construct the altitude dependence of the scattering coefficient and polarization in the mesosphere (altitudes from 60 to 90 km) at different angles. The undisturbed structure of the mesosphere without noticeable aerosol stratification on observation days makes it possible to estimate the temperature of the atmosphere at these altitudes.     

On the arc length of observations of a small solar system body sufficient to classify it as hazardous

This paper analyzes the accuracy of orbit determination calculated by observations of short arcs. In this case, we imposed the condition that the arc length and/or the distribution of arc observations should provide a confident classification of the orbit of a small celestial body allowing one to distinguish a potentially hazardous body, also including a threat of collision.     

The concept of a Space-Space interferometer for observations in mm and sub-mm wavebands

At present, space radio astronomers and engineers study the prospects of design of the second-generation ground-space interferometers for astrophysical research with the microsecond angular resolution of sources. The implemented Japanese VSOP project (1998–2003) and the Russian Radioastron project (under preparation for space flight) are related to the first generation. In this paper, the ideology and configuration of the Space-Space interferometer are considered. It would allow one to obtain principally new capabilities: to exclude the Earth’s atmosphere influence, to realize a quasi-phase-stable interferometer, and to remove the problems of electromagnetic compatibility with other services. Moreover, a capability will appear to carry out preliminary correlation processing onboard the spacecraft due to achievement of small residual uncertainties in signal delay and frequency and, owing to this, to realize onboard data compression in order to transmit data to the Earth by usual space communication channel.     

Super-elite plasma rings and the orbits of planets and satellites isomorphic to the orbits of electrons in the Bohr’s model of the hydrogen atom

This paper continues the series of papers [1–5] and generalizes the previous results to a proto-ring of magnetized plasma whose density decreases in the radial direction. The problem of quantization of the sector and orbital velocities, and of the radii and periods of revolution of elite plasma rings is considered. A new concept of super-elite rings is introduced. Their isomorphism with the orbits of the planets and planetary satellites in the Solar System is proved. This isomorphism also extends to the orbits of electrons in the Bohr’s model of the hydrogen atom.     

High-resolution simulations of the final assembly of Earth-like planets. 2. Water delivery and planetary habitability

The water content and habitability of terrestrial planets are determined during their final assembly, from perhaps 100 1,000-km "planetary embryos " and a swarm of billions of 1-10-km "planetesimals. " During this process, we assume that water-rich material is accreted by terrestrial planets via impacts of water-rich bodies that originate in the outer asteroid region. We present analysis of water delivery and planetary habitability in five high-resolution simulations containing about 10 times more particles than in previous simulations. These simulations formed 15 terrestrial planets from 0.4 to 2.6 Earth masses, including five planets in the habitable zone. Every planet from each simulation accreted at least the Earth's current water budget; most accreted several times that amount (assuming no impact depletion). Each planet accreted at least five water-rich embryos and planetesimals from the past 2.5 astronomical units; most accreted 10-20 water-rich bodies. We present a new model for water delivery to terrestrial planets in dynamically calm systems, with low-eccentricity or low-mass giant planets-such systems may be very common in the Galaxy. We suggest that water is accreted in comparable amounts from a few planetary embryos in a " hit or miss " way and from millions of planetesimals in a statistically robust process. Variations in water content are likely to be caused by fluctuations in the number of water-rich embryos accreted, as well as from systematic effects, such as planetary mass and location, and giant planet properties.     

Proton fluxes measured by low-orbit satellites

In this paper we consider the fluxes of protons in the energy range from 30 keV to 140 MeV recorded by instruments onboard the Russian satellites KORONAS-F and UNIVERSITETSKII and on the American satellites GOES-11 and NOAA-17. In order to estimate the reliability of the obtained data, the comparison of measurements of separate energy channels of these instruments between themselves is performed. Experimental fluxes of trapped protons are compared with the fluxes predicted by the AP8 model.     

Planetary waves according to simultaneous observations of <Emphasis Type="Italic">GPS</Emphasis> satellites and ground-based magnetic stations

On the basis of measurements made at Japanese magnetic stations and using GPS satellites for the 12 months of 2003, a comparison of simultaneous variations of three components of the magnetic field and total electron content (TEC) was carried out in the range of the planetary waves period. The correlation analysis has shown that almost synchronous variations exist within this range of periods at the ground-based magnetometer stations and in the TEC measurements both during strong magnetic disturbances and in quiet periods. The strong magnetic disturbances could be considered as a possible independent source of ionospheric variations within the planetary waves range, while the accompanying ionospheric storms could be a possible factor changing the conductivity of the lower ionosphere plasma. In quiet periods, the correlation of magnetic variations and disturbances in TEC is caused by the direct impact of atmospheric planetary waves on the lower ionosphere and can be related to variations of ionospheric currents due to the dynamo mechanism.     

Turbulent fluctuations of plasma and magnetic field parameters in the magnetosheath and the low-latitude boundary layer formation: Multisatellite observations on March 2, 1996

The results of simultaneous analysis of plasma and magnetic field characteristics measured on the INTERBALL/Tail Probe, WIND and Geotail satellites on March 2, 1996, are presented. During these observations the INTERBALL/Tail Probe crossed the low-latitude boundary layer, and the WIND and Geotail satellites measured the solar wind’s and magnetosheath’s parameters, respectively. The plasma and magnetic field characteristics in these regions have been compared. The data of the Corall, Electron, and MIF instruments on the INTERBALL/Tail Probe satellite are analyzed. Fluctuations of the magnetic field components and plasma velocity in the solar wind and magnetosheath, measured onboard the WIND and Geotail satellites, are compared. The causes resulting in appearance of plasma jet flows in the low-latitude boundary layer are analyzed. The amplitude of magnetic field fluctuations in the magnetosheath for a studied magnetosphere boundary crossing is shown to exceed the magnetic field value below the magnetopause near the cusp. The possibility of local violation of pressure balance on the magnetopause is discussed, as well as penetration of magnetosheath plasma into the magnetosphere, as a result of magnetic field and plasma flux fluctuations in the magnetosheath.     

Reconstruction of space weather physical parameters on 400-year scale

The main goal of this paper is to get physically informative comprehensive data about dynamics of the solar magnetic field, geomagnetic field, and interplanetary magnetic field over large time scales. The total sunspot magnetic flux, aa and IDV indices of geomagnetic activity, the IMF strength, the dipole-octopole index of the large-scale magnetic field of the Sun, and the open magnetic flux are reconstructed for 400 years. The reconstruction of the π index of the large-scale polar magnetic field of the Sun is performed for 150 years.     

The development of a Russian communication satellite of small class, operating in the geostationary and high-elliptical orbits

In 1994-1995 Lavochkin Association (Russia) together with the other enterprises in accordance with technical requirements of the Russian Space agency, developed a new Russian communication satellite of a small class that will operate in both the geostationary (GSO) and high-elliptical (HEO) orbits. This satellite may be injected into operational orbits using a SOYUZ-2 launch vehicle (LV) and a FREGAT upper stage (US) from Plesetsk and Baykonur space launch sites (SLS).The main reason for creating such a satellite was to decrease the cost of the support and development of the Russian communication geostationary satellites group.Russian satellites Horizont, Express, Ekran and Gals, which operate in GSO, are the basis of the space segment for communications, radio and TV broadcasting. All of these satellites are injected into GSO by the PROTON LV. PROTON is a launch vehicle of a heavy class. The use of a middle class LV instead of a heavy class will allow to reduce considerably the launch cost. The change of a heavy class LV to a LV of middle class determined one economic reason for this project. Besides, the opportunity to launch S/C into GSO from Russian Plesetsk SLS increases the independence of Russia in the domain of space communications, despite the presence of the contract with Kazachstan about the rent of Baykonur SLS. Finally, use of small satellites with a rather small number of transponders is more effective than the use of big satellites. It will allow also to increase a satellite group (by the launch of additional satellites) precisely in accordance to the development of the ground segment.