On the model structure of the gravity field of Mars     

V. N. Zharkov  T. V. Gudkova 《Solar System Research》2016,50(4):235-250

A discussion is presented about the constraints used in constructing a model for the internal structure of Mars. The most important fact is that the Martian chemical model proposed by Wänke and Dreibus (WD) has stood the test of time. This means that the chondritic ratio Fe/Si = 1.71 can be used as a constraint in constructing an interior structure model of the planet. Consideration is given to the constructing of the reference surface of Mars. It is concluded that the effectively hydrostatic-equilibrium model of Mars is well suited for this purpose. The areoid heights and gravity anomalies in the model of Mars are calculated. The results are shown in the figures (maps) and comments made. The results are compared with the similar data for the Earth. Mars deviates much more strongly from the hydrostatic equilibrium than the Earth. It is suggested that the average thickness of the Martian elastic lithosphere should exceed that of the Earth’s continental lithosphere.  相似文献   

Observations of the Galilean moons of Jupiter in 2013–2015 at Pulkovo     

N. V. Narizhnaya 《Solar System Research》2016,50(5):344-351

Observational results are presented for Jupiter and its Galilean moons from the Normal Astrograph at Pulkovo Observatory in 2013–2015. The following data are obtained: 154 positions of the Galilean satellites and 47 calculated positions of Jupiter in the system of the UCAC4 (ICRS, J2000.0) catalogue; the differential coordinates of the satellites relative to one another are determined. The mean errors of the satellites’ normal places in right ascension and declination over the entire observational period are, respectively: ε_α = 0.0065″ and ε_δ = 0.0068″, and their standard deviations are σ_α = 0.0804″ and σ_δ = 0.0845″. The equatorial coordinates are compared with planetary and satellite motion theories. The average (O–C) residuals in the two coordinates relative to the motion theories are 0.05″ or less. The best agreement with the observations is achieved by a combination of the EPM2011m and V. Lainey-V.2.0|V1.1 motion theories; the average (O–C) residuals are 0.03″ or less. The (O–C) residuals for the features of the positions of Io and Ganymede are comparable with measurement errors. Jupiter’s positions calculated from the observations of the satellites and their theoretical jovicentric coordinates are in good agreement with the motion theories. The (О–С) residuals for Jupiter’s coordinates are, on average, 0.027″ and–0.025″ in the two coordinates.  相似文献   

An improved model of radiative transfer for the NLTE problem in the NIR bands of CO<Subscript>2</Subscript> and CO molecules in the daytime atmosphere of Mars. 1. Input data and calculation method     

V. P. Ogibalov  G. M. Shved 《Solar System Research》2016,50(5):316-328

Advances in attacking the problem of radiative transfer in the near infrared (NIR) bands of CO₂ and CO under nonlocal thermodynamic equilibrium (NLTE) conditions depend on the accuracy of taking into account the radiation processes and inelastic collisions of CO₂ and CO molecules. The focus of the paper is to substantially improve the physical model of the problem and update the calculation method. It is the first time the surface albedo is introduced into the problem of the molecular emission under NLTE conditions. The values of the rate constants for inelastic molecular collisions and their temperature dependences have been radically updated. In some cases, since laboratory measurements of these constants are lacking, different versions are provided for them. The relative abundance of CO₂ and CO isotopologues is based on the ratios of isotope abundances for the elements C and O obtained from the measurements in the atmosphere of Mars. The intensity of extraterrestrial solar NIR radiation is specified on the base of the high-accuracy ground-based measurements. In the method for calculating the populations of vibrational states, we pioneer in completely taking into account the overlapping of spectral lines in the NIR bands of CO₂ and CO.  相似文献   

A technique for processing of planetary images with heterogeneous characteristics for estimating geodetic parameters of celestial bodies with the example of Ganymede     

A. E. Zubarev  I. E. Nadezhdina  E. S. Brusnikin  I. P. Karachevtseva  J. Oberst 《Solar System Research》2016,50(5):352-360

The new technique for generation of coordinate control point networks based on photogrammetric processing of heterogeneous planetary images (obtained at different time, scale, with different illumination or oblique view) is developed. The technique is verified with the example for processing the heterogeneous information obtained by remote sensing of Ganymede by the spacecraft Voyager-1, -2 and Galileo. Using this technique the first 3D control point network for Ganymede is formed: the error of the altitude coordinates obtained as a result of adjustment is less than 5 km. The new control point network makes it possible to obtain basic geodesic parameters of the body (axes size) and to estimate forced librations. On the basis of the control point network, digital terrain models (DTMs) with different resolutions are generated and used for mapping the surface of Ganymede with different levels of detail (Zubarev et al., 2015b).  相似文献   

Large-aperture telescopes in the problems of near-Earth astronomy     

V. P. Aleshin  E. A. Grishin  O. A. Ivlev  D. D. Novgorodtsev  V. D. Shargorodsky 《Kinematics and Physics of Celestial Bodies》2016,32(5):255-259

Telescopes with aperture higher than 3 m and with travel rate of optical axis of more than 4 angular degrees per second are examined. These telescopes are used for estimating the situation in near-Earth space. Up to now, there are three telescopes with such parameters: SOR, AMOS, SST (all in the United States). A telescope of the same class with aperture of 3.12 m (information telescope TI-3.12) is under completion at Altai Optical Laser Center. The main technical performances of the TI-3.12 telescope are described in the paper. Current problems are defined and ways for their solution are presented.  相似文献   

Investigations of space debris at Terskol observatory     

N. S. Bakhtigaraev  P. A. Levkina  L. V. Rykhlova  A. V. Sergeev  V. K. Taradiy  N. V. Karpov  V. V. Chazov 《Kinematics and Physics of Celestial Bodies》2016,32(5):237-240

Within the framework of the “Astronomy in the Elbrus Region” international program, investigations of space debris objects using optical measurements are carried out at the observation complex of the Zeiss-2000 telescope (developed by the International Center for Astronomical and Medico-Ecological Research, National Academy of Sciences, Ukraine) at Terskol Observatory. The objectives of this study are to detect, catalog, and determine the physical characteristics of small-sized space debris fragments, maintain orbit catalogs, and investigate the influence of nongravitational perturbations on the orbital motion and the evolution of orbits of these fragments.  相似文献   

On the Origin of Differences in Helicity Parameters Derived from Data of Two Solar Magnetographs     

Haiqing Xu  Hongqi Zhang  K. Kuzanyan  T. Sakurai 《Solar physics》2016,291(8):2253-2267

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Acoustic and Slow Sausage Oscillations in the Stratified Solar Photosphere: Hinode Observations and Phase Relationships     

Y. T. Tsap  A. V. Stepanov  Y. G. Kopylova 《Solar physics》2016,291(11):3349-3356

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A Revised Collection of Sunspot Group Numbers     

J. M. Vaquero  L. Svalgaard  V. M. S. Carrasco  F. Clette  L. Lefèvre  M. C. Gallego  R. Arlt  A. J. P. Aparicio  J.-G. Richard  R. Howe 《Solar physics》2016,291(9-10):3061-3074

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Rayleigh–Taylor Instability and Excitation of Super-Dreicer Electric Fields in the Solar Chromosphere     

V. V. Zaitsev  P. V. Kronshtadtov  A. V. Stepanov 《Solar physics》2016,291(11):3451-3459

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