Solar System Research最新文献

The paper examines two habitable zones with different physical conditions on exoplanets: planets with liquid water on the surface and conditions close to Earth’s (“Goldilocks Zone”), and cold worlds with icy surfaces and subsurface oceans (“Snow Maiden Zone”). The mechanisms of exchange of matter and energy between subglacial oceans and the surrounding space are discussed. It is noted that the biospheres of icy worlds with internal oceans are better protected from unfavorable external cosmic conditions. Subglacial biospheres are weakly dependent on the radiation intensity and flare activity of their parent stars, and the number of planets in the Universe with the physical conditions of the icy Snow Maiden Zone significantly exceeds the number of planets in the very limited Goldilocks Zone. It can be assumed that it is the biospheres of icy oceanic worlds that are much more widespread in the Universe compared to terrestrial-type biospheres.

The study of microorganism tolerance to extreme influences is an integral part of astrobiology. Despite the large number of works in this field, the limits of maintaining viability and activity remain uncertain, and they are probably much wider than the currently known boundaries, especially taking into account the adaptive capabilities of microorganisms. In the vast majority of astrobiological experiments, a very limited set of organisms and the impact of a small number of factors are studied. It seems natural that research gradually develops from modeling simple systems (pure cultures and single-factor impacts) to more complex ones, closer to hypothetical extraterrestrial ecosystems. Nevertheless, studies of the most complex systems (microbial communities under the complex action of extraterrestrial conditions in laboratory and space experiments) are still extremely few in number. At the same time, some features of multifactor impacts and the response of complex microbial systems to such impacts are often given little attention. This paper attempts to summarize some data on the tolerance of microorganisms to extreme factors of extraterrestrial space, as well as to outline a number of insufficiently studied promising fields of astrobiological research.

The concept of the origin of life outside the Earth is currently one of the dominant directions of theoretical, experimental and observational scientific research. The problem of the origin of life is interdisciplinary and includes the most pressing issues of astronomy, biology, paleontology, organic chemistry and other sciences. This issue of the journal is devoted to the astronomical aspects of the origin and development of life.

The paper describes the improvements made by the authors to the previously published Numerical Model of the Motion of Artificial Lunar Satellites (ALS). The results of a study of the dynamics of cislunar objects obtained by numerical modeling are presented. It is shown that the short lifespan of low-flying objects in orbits, revealed by a number of authors, is explained solely by the influence of the complex gravitational field of the Moon, primarily the radial component of the force acting on the satellites. The features of the influence of light pressure (LP) on cislunar objects are considered. It is shown that LP expands the range of action of apsidal-nodal resonances that arise in the movement of cislunar objects.

The degassing of basic silicate minerals (olivines, pyroxenes, plagioclases) that make up mantle rocks similar in chemical composition to lunar mare basalts has been studied. A setup specially designed for these tasks was used, previously used in the study of chondrite degassing. The results of experimental studies on stepwise heating (without accumulation) with determination of the composition of released gases using gas chromatography methods in the temperature range from 200 to 1000°C are presented. The composition of the released gases was compared with the fugacity of oxygen in olivines. Raman and IR spectra of both the original minerals and minerals after isothermal annealing at various temperatures were obtained. Based on them, the course of thermal transformation of the crystalline structure of minerals was traced and estimates of their stability were obtained. The composition of silicate minerals was compared with samples of lunar soil delivered by the Chinese space mission Chang’e-5.

The paper propose the method for solving the Euler–Lambert problem proposed by V.A. Egorov and based on the works by D.E. Okhotsimsky, devoted to the analysis of a set of flight trajectories between two given points in the central Newtonian field. When considering the Euler–Lambert problem as the inverse problem of ballistics (dynamics), we have succeeded in developing a new effective method for determining the orbit corresponding to a given flight time. It is logical to name this approach the Okhotsimsky–Egorov method. In the considered approach, the parameter of the set of flights is the initial flight-path angle. The advantages of the proposed method are the limited and understandable structure of the domain of definition of solutions, the simplicity and clarity of the algorithm, and the clear dependence of the solution on the initial velocity. It enables a qualitative analysis of flight trajectories and the construction of effective numerical methods. To solve the Euler–Lambert problem Halley’s numerical method was used. A computational complexity analysis of considered algorithm was carried out and demonstrated its high efficiency.

When passing through the Earth’s atmosphere, cosmic bodies are subjected to significant loads due to the impact of high-speed gas flow on their surface. Under the influence of aerodynamic forces and strong heat flows, these bodies are destroyed. The mechanisms of destruction depend on their composition, structure, speed, size and strength. Artificial space bodies move in the atmosphere, generally maintaining their orientation in space, and reach the surface, maintaining integrity due to their high strength. As a result of surface destruction of the frontal part of these bodies, destruction products enter the plasma layer surrounding them when moving in the atmosphere. The design features of the Soyuz descent vehicle made it possible to study the dust component of the plasma layer from the deposits deposited on the porthole. Data on particles detected on the surface of the spacecraft are analyzed, and the results of a statistical analysis of the resulting particle size distribution are presented. It is shown that the distribution curve is well described by a power law.

Based on the successful landings of landing modules (LM) on the surface and the introduction of aerostat probes (AP) into the air, the feasibility of exploring Venus by an AP drifting in the cloud layer of its atmosphere using short-term descents and landings on its surface has been substantiated. Mathematical modeling was performed to confirm the feasibility of short-term AP drops with a scientific package (SP) in a thermostatted compartment for sampling soil, aerosols and gases and remote sensing (RS) in various regions remote from each other near the surface of the planet Venus for their analysis during a long drift at the height of the cloud layer. Using the example of individual SP devices for geochemical and geophysical studies of Venusian rocks, the scenario and capabilities of AP are shown, which significantly expand both the range of scientific tasks to be solved and the capabilities of the scientific equipment itself.

In the period December 12, 2022, to February 28, 2023, we performed a series of UBVRI observations of 65 asteroids, including 50 primitive-type objects, which could be observed near perihelion at that time, and calculated their approximated reflectance spectra. The observations were aimed at searching for spectral signs of sublimation-driven dust activity in the asteroids and formation of a transient dust exosphere, which are caused by the presence of Н₂О ice in their interior and the highest subsolar temperature. Based on the analysis of the accuracy and shape of approximated reflectance spectra of the primitive-type asteroids, a set of which was conventionally restricted by the geometric albedo value not exceeding 0.10, we found sublimation-driven dust activity in asteroids 164 Eva, 360 Carlova, and 750 Oskar by distinct short-term variations in the reflectance of these asteroids in the U band. During one of the nights, similar spectral changes and sublimation-driven dust activity related to them were detected in asteroid 629 Bernardina; the geometric albedo of this asteroid is somewhat higher (0.14 or 0.19), which may be indicative of a heterogeneous composition of its material and, apparently, a local outcropping of water ice on its surface. Moreover, in three asteroids of a high-temperature type, 757 Portlandia, 1121 Natascha, and 1687 Glarona, noticeable variations were detected in the entire spectral range; they may be connected with ejection of submicron dust particles from the surface by some other mechanisms. To substantiate and interpret the results of observations, we numerically modeled the reflectance spectra of conditional asteroids of taxonomic types C and S (with low- and high-temperature mineralogy, respectively), which are enveloped by an optically thin dust exosphere containing aggregate or homogeneous submicron particles of different composition. On the basis of this modeling, we introduce a quantitative criterion to identify a weak sublimation-driven dust activity in primitive-type asteroids in the visible range.

The aim of this paper is to investigate the motion properties of the infinitesimal body under the effects of gravitational forces, the quantum correction, variable mass, modified Newtonian force, interaction between bodies, triaxial parameters, Coriolis and centrifugal forces in the restricted three-body configuration. Using Jeans law, Meshcherskii space-time transformations and the above perturbations, we evaluate the equations of motion and quasi-Jacobian integral. And then, we numerically illustrate the locations of equilibrium points, regions of motion, Poincare surfaces of section, basins of attraction, periodic orbits and stability of the equilibrium points.