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Valley Relief of the Northeastern Part of Terra Cimmeria on Mars
Mukhamedzhanova, A. E.
A study of the valley topography of the northeastern part of Terra Cimmeria on Mars was carried out. The results of the study allow us to draw the following conclusions. (1) The morphology of the studied valley systems corresponds to their presumed fluvial origin. (2) The remains of the paleodelta in the Gusev crater, fragments of terrace levels t…
Gaia Data Release 3: Distribution of Spectral Groups of Near-Earth Asteroids
Kovaleva, D. A.; Shcherbina, M. P.; Shustov, B. M.
Based on the data from the third edition of the Gaia catalog, containing the reflectance spectra of asteroids, studies of near-Earth asteroids (NEAs) were carried out. The reflectance spectra of about 100 representatives of the Aten, Apollo and Amor groups were used to determine their spectral class. For 47 asteroids such an assessment was made fo…
Calculation of the Non-Gravitational A2 Parameter Using Ground-Based Observations of the Apparent Close Approaches between Near-Earth Asteroids and Gaia Stars
Gorshanov, D. L.; Khovrichev, M. Yu.; Bikulova, D. A.
The Yarkovsky effect is one of the noticeable factors in the orbital evolution of near-Earth asteroids (NEAs). The A2 non-gravitational parameter describes the corresponding acceleration in the NEA motion model. This parameter can be derived from astrometric observations of the NEA. We present the results of astrometric observations of …
Internal Structure of the Magnetic Funnel in the Polar Heliosphere
Kislov, R. A.
According to data obtained by the Ulysses spacecraft in 2017, high-latitude current sheets have been discovered in the polar heliosphere. They have been observed during solar activity minima in 1994 and 2007 at a distance of 2–3 AU above the south pole of the Sun. The discovered current sheets formed a conical surface rotating as a whole around th…
New Results of Radiation Study on Board TGO ExoMars in 2018–2023
Mitrofanov, I.; Golovin, D.; Kozyrev, A. +13 more
The article provides a brief description of the Liulin-MO dosimeter, which is part of the FREND (Fine Resolution Epithermal Neutron Detector) device installed on the TGO (Trace Gas Orbiter) spacecraft of the ExoMars-2016 mission. Since April 2018, TGO has been operating in orbit around Mars. Data are presented on the radiation environment in the o…
Thermal Sounding of the Martian Atmosphere Using the ACS TIRVIM FT-IR Spectrometer on Board ExoMars TGO: Method for Solving the Inverse Problem
Fedorova, A. A.; Grassi, D.; Shakun, A. V. +8 more
This paper presents a method for solving the inverse problem of thermal sounding using calibrated data from the ACS TIRVIM experiment on board the ExoMarsTrace Gas Orbiter. The 1.7-17 µm range TIRVIM Fourier spectrometer as part of the ACS instrument complex aboard the ExoMarsTGO operates in the nadir and solar occultation modes in orbit around Ma…
Wind Speed Variations at the Venus Cloud Top above Aphrodite Terra According to Long-term UV Observations by VMC/VENUS Express and UVI/AKATSUKI
Ignatiev, N. I.; Zasova, L. V.; Titov, D. V. +4 more
Series of consecutive UV (365 nm) images of Venus cloud coverage provide a way to investigate dynamics of the mesosphere. An unprecedented series of such images was obtained by the VMC/Venus Express (ESA) and UVI/Akatsuki (JAXA) cameras from 2006 to 2022. At 10°S long-term variations in the mean zonal and meridional wind speed are observed with a …
Features of Designing a Star Catalog for Orientation Sensors of Space Vehicles
Avanesov, G. A.; Elyashev, Ya. D.
A brief history of the creation of star orientation sensors at the Space Research Institute of the Russian Academy of Sciences (IKI RAS) and star catalogs for them is presented. An experiment carried out in the early 1970s on synchronous photography of stars and the Earth's surface from the manned stations Salyut-2 and -3 is described. The difficu…
Transport Characteristics of a Hierarchical Near-Surface Layer of the Nucleus of Comet 67P/Churyumov-Gerasimenko
Blum, J.; Hartogh, P.; Rezac, L. +3 more
In this paper, we develop previous studies that considered a free molecular gas flow through a dust porous mantle of a cometary nucleus. Before, we considered various types of both homogeneous and heterogeneous layers built of nonintersecting spheres, including the layers containing microscopic cracks and inner cavities. At the same time, data fro…
Spectral Signs of Simultaneous Sublimation Activity and the Appearance of a Dust Exosphere on Eight Asteroids of the Main Belt Near Perihelion
Shcherbina, M. P.; Busarev, V. V.; Savelova, A. A. +1 more
In December 2020, at the 2-m telescope of the Terskol branch of the Institute of Astronomy, we carried out spectrophotometric observations in the range of ~0.36-0.95 µm of nine asteroids of the Main Belt (19 Fortuna, 52 Europa, 102 Miriam, 177 Irma, 203 Pompeja, 250 Bettina, 266 Aline, 379 Huenna, and 383 Janina), which were near perihelia o…