Meteoric Particles Research Articles

DEVELOPMENT OF THE MATHEMATICAL MODEL, ALGORITHM AND SOFTWARE FOR SELECTION OF THE SPACECRAFT PROTECTION AGAINST IMPACT OF THE METEORITES AND SPAСE DEBRIS

The paper deals with the sources of high speed bodies and particles of the natural and artificial origin which are dangerous for the spacecraft operation. The paper presents the parameters of certain groups of the meteoric particles and the sources space debris. The following ways allow the spacecrafts to avoid collision with space debris: change of spacecraft orbit, and optimal protection of the spacecraft surface. An actual problem of creation of the spacecraft protection for spacecraft operating on the near Earth orbit for a long time includes development of the algorithms and software for the optimization of spacecraft screen protection and reduce mass. Development of the algorithms and software for the spacecraft multiunit protection solves the problem of optimization of spacecraft surface screen multi-unit protection for basic models as cube and cylinder (in the algorithmic languages of Fortran and BUILDER-4) by the method of dynamic programming with Pareto sets. Moreover, we developed the visualization programs of the optimization results and the utilities that provide interface of the calculating programs and databases in Windows environment. The programs include plotting, providing the calculation clearness.

Results of the Ion–Neutral Collision Frequency Measurements in the Lower Thermosphere by the Method of Resonance Scattering of the Radio Waves by Artificial Periodic Irregularities

UDC 550.388.2+551.510.536 We present for the first time the experimental data on the frequency of ion–neutral collisions at the altitudes of the ionospheric E layer, which were obtained by the method of resonance scattering of the radio waves by artificial periodic irregularities of the ionospheric plasma. The measurements were carried out in different time periods from 1990 to 2012. Time and altitude dependences of the collision frequency are given. The dependence of the collision frequency on the solar and geomagnetic activity has been analyzed. Collisions of electrons and ions with atoms and molecules play an important role in physics of the ionosphere and atmosphere. In particular, they determine the friction force and should be taken into account in the equations of motion of a medium when its viscosity increases. The frequency of ion–neutral collisions affects the energy and momentum transfer processes [1–4]. When propagation of internal gravity waves above 100 km is considered, it is needed to allow for dissipation due to increasing viscosity of the medium [4–7], which is directly related to collisions. The frequency νin of collisions between ions and neutral molecules should also be taken into account when the low-frequency processes associated with the plasma conductivity are analyzed (see, e. g., [8]). However, the experimental data on νin are fairly scarce. Meanwhile, considerable variations in the ion–neutral collision frequency can be observed in the upper ionosphere. These variations are due most frequently to the neutral atmosphere density variations caused by the transmission of internal gravity and tidal waves. Variations from day to day can be due to propagation of planetary waves. At the altitudes of the upper mesosphere and lower thermosphere, the neutral atmosphere density variations according to the lidar data can exceed 20%, while the temperature variations can reach 70 K [9, 10]. Observations suggest that during propagation of gravity waves the collision frequency can be changed by a factor of 1.5–2 for half an hour [9, 11]. The collision frequency variations can also be a consequence of variations in the composition of both the ion component and the neutral atoms and molecules. In particular, in the ionospheric E region, variations in the ion–neutral collision frequency can be caused by the penetration of metal meteor particles and ions that contribute to the formation of both the sporadic layers of the electron density and the layer with increased content of Na, K, Fe, etc. atoms [12–15]. In this paper, we present the results of determining the ion–molecule collision frequency obtained by the method of resonant scattering of radio waves by artificial periodic irregularities of the plasma at the altitudes of the ionospheric E region.

First 3‐D simulations of meteor plasma dynamics and turbulence

AbstractMillions of small but detectable meteors hit the Earth's atmosphere every second, creating trails of hot plasma that turbulently diffuse into the background atmosphere. For over 60 years, radars have detected meteor plasmas and used these signals to infer characteristics of the meteoroid population and upper atmosphere, but, despite the importance of meteor radar measurements, the complex processes by which these plasmas evolve have never been thoroughly explained or modeled. In this paper, we present the first fully 3‐D simulations of meteor evolution, showing meteor plasmas developing instabilities, becoming turbulent, and inhomogeneously diffusing into the background ionosphere. These instabilities explain the characteristics and strength of many radar observations, in particular the high‐resolution nonspecular echoes made by large radars. The simulations reveal how meteors create strong electric fields that dig out deep plasma channels along the Earth's magnetic fields. They also allow researchers to explore the impacts of the intense winds and wind shears, commonly found at these altitudes, on meteor plasma evolution. This study will allow the development of more sophisticated models of meteor radar signals, enabling the extraction of detailed information about the properties of meteoroid particles and the atmosphere.

DUST FROM COMET 209P/LINEAR DURING ITS 2014 RETURN: PARENT BODY OF A NEW METEOR SHOWER, THE MAY CAMELOPARDALIDS

We report a new observation of the Jupiter-family comet 209P/LINEAR during its 2014 return. The comet is recognized as a dust source of a new meteor shower, the May Camelopardalids. 209P/LINEAR was apparently inactive at a heliocentric distance rh = 1.6 au and showed weak activity at rh < 1.4 au. We found an active region of <0.001% of the entire nuclear surface during the comet's dormant phase. An edge-on image suggests that particles up to 1 cm in size (with an uncertainty of factor 3-5) were ejected following a differential power-law size distribution with index q=-3.25+-0.10. We derived a mass loss rate of 2-10 kg/s during the active phase and a total mass of ~5x10^7 kg during the 2014 return. The ejection terminal velocity of millimeter- to centimeter-sized particles was 1-4 m/s, which is comparable to the escape velocity from the nucleus (1.4 m/s). These results imply that such large meteoric particles marginally escaped from the highly dormant comet nucleus via the gas drag force only within a few months of the perihelion passage.

Introducing a new stratospheric dust-collecting system with potential use for upper atmospheric microbiology investigations.

The stratosphere is a known host to terrestrial microbes of most major biological lineages, but it is also host to incoming meteoric dust. Our goal is to (1) introduce DUSTER (Dust in the Upper Stratosphere Tracking Experiment and Retrieval), an active collector for the nondestructive collection of nano- to micrometer particles in the stratosphere between 30 and 40 km altitude, and (2) demonstrate that even a single particle can be collected free of resident atmospheric and laboratory contaminant particles. DUSTER improves the pervasive and persistent contamination problem in the field of aerobiology research. Here, we demonstrate the collector's advances by the identification of a (terrestrial) spore particle found among a population of nanometer-scale inorganic meteoric particles. This was possible because the size, shape, morphology, and chemical composition of each particle can be determined while still on the collector surface. Particles can be removed from DUSTER for specific laboratory analyses. So far, DUSTER has not been fitted for aerobiological purposes; that is, no attempts were made to sterilize the collector other than with isopropyl alcohol. Its design and laboratory protocols, however, allow adjustments to dedicated aerobiological sampling opportunities.

Meteor-shower complex of asteroid 2003 EH1 compared with that of comet 96P/Machholz

Aims. We studied the structure of the meteoroid particle complexes released from asteroid 196 256 (2003 EH1) to reveal the relationship to the meteor showers observed in Earth’s atmosphere that belong to this complex as well. In addition, we studied the relationship between the asteroid and comet 96P/Machholz, which is situated in the same orbital phase space. Methods. For nine perihelion passages of the parent asteroid in the past, we modeled the associated theoretical streams and followed their dynamical evolution until the present. Subsequently, we analyzed the orbital characteristics of the modeled streams, especially of the parts that approach Earth’s orbit. Results. We confirm the filamentary structure of the complex, which is qualitatively identical to the complex of 96P. Six wellestablished and two minor filaments approach the orbit of the Earth, producing four well-known meteor showers, daytime Arietids, Southern δ-Aquarids, Quadrantids, and Northern δ-Aquarids. The filaments corresponding to the Arietids and δ-Aquarids S and N constitute the ecliptical component, and those corresponding to the Quadrantids and their southern counterpart constitute the toroidal component of the complex.

Resonant behavior of comet Halley and the Orionid stream

AbstractComet 1P/Halley has the unique distinction of having a very comprehensive set of observational records for almost every perihelion passage from 240 B.C. This has helped to constrain theoretical models pertaining to its orbital evolution. Many previous works have shown the active role of mean motion resonances (MMR) in the evolution of various meteoroid streams. Here, we look at how various resonances, especially the 1:6 and 2:13 MMR with Jupiter, affect comet 1P/Halley and thereby enhance the chances of meteoroid particles getting trapped in resonance, leading to meteor outbursts in some particular years. Comet Halley itself librated in the 2:13 resonance from 240 B.C. to 1700 A.D. and in the 1:6 resonance from 1404 B.C. to 690 B.C., while stream particles can survive for time scales of the order of 10,000 yr and 1,000 yr in the 1:6 and 2:13 resonances, respectively. This determines the long‐term dynamical evolution and stream structure, influencing the occurrence of Orionid outbursts. Specifically, we are able to correlate the occurrence of enhanced meteor phenomena seen between 1436–1440, 1933–1938, and 2006–2010 with the 1:6 resonance and meteor outbursts in 1916 and 1993 with the 2:13 resonance. Ancient as well as modern observational records agree with these theoretical simulations to a very good degree.

The meteor-shower complex of 96P/Machholz revisited

Aims. The structure of the complex of meteoroid particles released from comet 96P/Machholz is studied to reveal a relationship among the meteor showers observed in the Earth’s atmosphere that belong to this complex. Methods. For eight perihelion passages of the parent comet in the past, we model theoretical streams associated with comet 96P and follow their dynamical evolution until the present. Subsequently, we analyze the orbital characteristics of the streams, especially of their parts approaching the Earth’s orbit. Results. The dynamics of the stream is controlled by Jupiter, which changes the initial orbits of the particles into the orbits situated within several specific corridors. It thus creates a filamentary structure of the complex. Six filaments approach the orbit of the Earth producing four well-known meteor showers and two showers, whose identification with κ -Velids and α -Cetids is not certain. The known showers, in order of the predicted abundance of meteors, are daytime Arietids, Southern δ -Aquarids, Quadrantids, and Northern δ -Aquarids. The filaments corresponding to the Arietids, δ -Aquarids S and N, and possibly α -Cetids constitute the ecliptical component and those corresponding to the Quadrantids and possibly κ -Velids constitute the toroidal component of the complex.

Present State and Prospects for the Meteor Research in Ukraine

AbstractODESSA. Systematical study of the meteor events are being carried out since 1953. In 2003 complete modernization of the observing technique was performed, and TV gmeteor patrolh on the base of WATEC LCL902 cameras was created. @ wide variety of mounts and objectives are used: from Schmidt telescope F = 540 mm, F/D = 2.25 (field of view FOV = (0.68x0.51) deg, star limiting magnitude SLM = 13.5 mag, star astrometric accuracy 1-2 arcsec) up to Fisheye lenses F = 8 mm, F/D = 3.5 (FOV = (36x49) deg, SLM = 7 mag). The database of observations that was collected between 2003 and 2012 consists of 6176 registered meteor events. Observational programs on basis and non-basis observations in Odessa (Kryzhanovka station) and Zmeiny island are presented. Software suite of 12 programs was created for processing of meteor TV observations. It enables one to carry out the whole cycle of data processing: from image preprocessing up to orbital elements determination. Major meteor particles research directions: statistic, areas of streams, precise stream radiant, orbit elements, phenomena physics, flare appearance, wakes, afterglow, chemistry and density. KYIV. The group of meteor investigations has been functioning more than twenty years. The observations are carried out simultaneously from two points placed at the distance of 54 km. Super-isocon low light camera tubes are used with photo lens: F = 50mm, F/D = 1.5 (FOV = (23.5 x 19.0) deg, SLM = 9.5 mag), or F = 85, F/D = 1.5 (FOV = (13x11) deg, SLM = 11.5 mag). Astrometry, photometry, calculation of meteor trajectory in Earth atmosphere and computation of heliocentric orbit are realized in developed gFalling Starh software. KHARKOV. Meteor radio-observations have begun in 1957. In 1972, the radiolocation system MARS designed for automatic meteor registration was recognized as being the most sensitive system in the world. With the help of this system 250 000 faint meteors (up to 12 mag) were registered between 1972 and 1978 (frequency 31.1 MHz, particle masses 10−3 ~ 10−6 g). Simultaneously, millions of reflections were registered for even fainter meteors (up to 14 mag). Information about 250 000 meteors and 5160 meteor streams is included in database. This is an unique material that can be used for hypotheses testing, as well as for creation new theories about meteor phenomena. Models of the meteor matter distribution in the Earthfs atmosphere, near-Earth space and in the Solar system, influence on surface of spacecrafts were developed. NIKOLAEV. The optical and radio observations of meteors have begun in 2011. Two WATEC LCL902 cameras are used with photo lens F = 85 mm, F/D = 1.8 (FOV = (3.2x4.3), SLM = 12 mag, star astrometric accuracy 1-6 arcsec). Original software was developed for automatic on-line detection of meteor in video stream. During 2011 year 105 meteor events were registered (with angular length (0.5-4.5) deg and brightness (1-5) mag). Error of determination of the meteor trajectory arc ~ (10-12) arcsec. Error of determination of the large circle pole of the meteor trajectory is ~ (3-13) arcmin. In the radio band observations of meteors are performed by registration of signal reflected from the meteor wake. As a signal source the over-the-horizon FM station in Kielce (Poland) is used. Narrow-beam antenna, computer with TV/FM tuner and audio recording software are used to perform radio observations. Original software was developed for automatic detection of meteor in audio stream.

Investigation on spectral character of ELF electromagnetic radiations during Leonid 2009 meteor shower

There are several reports of simultaneous optical flashes as well as audible sounds called electrophonics during the passage of meteors through the Earth’s atmosphere, but the exact physical mechanism behind these phenomena is still poorly understood. Some experiments performed during meteor showers indicate the presence of ELF-VLF electromagnetic waves generated simultaneously with the passage of a meteor, which after suitable transduction are converted into audible sound waves. In this context, the present paper investigates the temporal and spectral character of ELF electromagnetic waves produced during the Leonid meteor shower on 18th November, 2009. A well calibrated broadband GPS locked software receiver was used to perform the experiment at the Department of Physics, Tripura University, India (23.50° N 91.25° E). The analysis of temporal data and dynamic spectrogram reveals distinct electromagnetic pulses in the frequency range of a few Hz to 2 kHz during the predicted time of peak activity of the shower. The spectral character of these pulses is found to be completely different from the spectral signatures originating from lightning discharges. During the peak activity period, the meteor counts using ELF method is found to be around 11,000 meteors hr−1, which is around 137 times more than the worldwide reported visible rate. The observational results are discussed from the viewpoint of deposition of meteoric dust particles and its interaction with ionospheric plasma, leading to emission of electromagnetic waves during the passage of meteors through the Earth’s atmosphere.

Tidal disruption of NEAs - a case of Příbram meteorite

This work studies the dynamical evolution of a possible meteor stream along the orbit of the P\v{r}\'{i}bram meteorite, which originated in the tidal disruption of the putative rubble-pile-like parent body during a close approach to the Earth. We assumed the disruption at the time when the ascending or descending node of the parent orbit was close to the Earth's orbit. In the last 5000 years, the P\v{r}\'{i}bram orbit has crossed the Earth orbit twice. It happened about 4200 years and 3300 years ago. In both cases, we modeled the release of particles from the simplified model of rotating asteroid, and traced their individual orbital evolution to the current date. It takes several hundred years to spread released meteoroids along the entire orbit of the parent body. Even today, the stream would be relatively narrow. Considering a model parent body with physical parameters of the asteroid Itokawa, the complete disintegration of the object produced 3.8$\times10^{11}$ meteoroid particles with diameter $\geq$ 1\,cm. The meteor activity observed from the Earth is revealed and justification of follow-up observation during suggested activity of the shower in the first two weeks of April is discussed. The Earth's tidal forces would disintegrate a fraction of NEA population into smaller objects. We evaluate the upper limit of mass of disintegrated asteroids within the mean NEA lifetime and the contribution of disrupted matter to the size distribution of the NEA.

Possible impact of interplanetary and interstellar dust fluxes on the Earth’s climate

This article considers the process of entry of cosmic substance into the Earth’s atmosphere and the further evolution of the formed extraterrestrial aerosol. It is shown that meteorite-derived aerosol generated in the atmosphere may affect the Earth’s climate in two ways: (a) particles of meteoric haze may serve as condensation nuclei in the troposphere and stratosphere; (b) charged meteor particles residing in the mesosphere may markedly change (by a few percent) the total atmospheric resistance and, thereby, affect the global current circuit. Changes in the global electric circuit, in turn, may influence cloud formation processes. The obtained results argue for the fact that the meteoric dust in the Earth’s atmosphere is potentially one of the important climate-forming agents. It is shown that the amount of interstellar dust in the Earth’s atmosphere is too small to have a considerable affect on atmospheric processes.

Meteor-F detector of space dust

The instrument for the registration of the physicodynamical parameters of meteor particles applied in the spacecraft of the Phobos-Grunt project and the methods of its calibration are described in the paper.

Meteoric particles with implicit hyperbolic orbits

Meteoric particles with implicit hyperbolic orbits

Orbital structure of the Kuiper belt and its contribution in the near-Earth asteroid and meteor population

Numerical calculations are given to describe evolution of orbits of simulated and real Kuiper belt objects for large intervals of time. Gravitational perturbations caused by all major planets have been taken into account, and, when considering small particles, Poynting-Robertson nongravitational effect has also been incorporated. Large orbit scattering of the Kuiper belt objects regarding the semimajor axes and eccentricities is shown to be due to their evolution over millions of years. Relative contribution of great objects and meteor particles from the Kuiper belt into the near-Earth population is believed to be extremely small.

Charged meteoric particles as ice nuclei in the mesosphere: Part 2: A feasibility study

Recondensed meteoric material, so-called meteoric smoke, has long been considered the main candidate for condensation nuclei for mesospheric ice formation. Recently however, model studies have shown that meteoric smoke particles are transported away from the polar region, where ice phenomena such as noctilucent clouds occur, before they can grow large enough to serve as ice condensation nuclei. In the accompanying paper it is argued that charging of the meteoric smoke particles may solve this dilemma by significantly altering the efficiency of the particles as condensation nuclei. In the present paper, the feasibility of this idea is investigated more quantitatively, by analysing the time scales of processes such as charging, recombination, and particle growth. Despite large uncertainties, especially in the charging efficiency of the smallest smoke particles, we show that reasonable assumptions yield number densities of charged condensation nuclei that are consistent with what is expected for mesospheric ice phenomena.

Techniques for positional measurements of telescopic meteor TV images

We present the results of our positional reduction of the observational material obtained using a meteor patrol based on a Schmidt telescope and a TV CCD detector. More that 1000 telescopic meteors were recorded in three years of meteor patrolling. Techniques for the cataloging and positional reduction of 3050 TV images with meteor trails are described. We have developed a technique for measuring the images of reference stars to determine the rectangular coordinates in the image frame. We discuss the achieved accuracy of determining the equatorial coordinates of reference and check stars by Turner’s method (of the order of a few arcseconds). We have developed software that allows the rectangular coordinates of meteor trajectory points to be determined after the meteor image reduction. These coordinates are used to determine the equatorial coordinates of the poles of the great circles of meteor trajectories (the angular length is not less than 15′ with an accuracy of at least 4′. We consider the possibility of using Stanyukovich’s method to determine the equatorial coordinates of radiants for non-basis meteor observations. The accuracy of determining the radiant coordinates has been estimated to be 4′–5′. Prospects for obtaining the kinematic characteristics of meteor particles are discussed.

Detection of an intergalactic meteor particle with the 6-m telescope

On July 28, 2006 the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences recorded the spectrum of a faint meteor. We confidently identify the lines of FeI and MgI, OI, NI and molecular-nitrogen (N2) bands. The entry velocity of the meteor body into the Earth’s atmosphere estimated from radial velocity is equal to 300 km/s. The body was several tens of a millimeter in size, like chondrules in carbon chondrites. The radiant of the meteor trajectory coincides with the sky position of the apex of the motion of the Solar system toward the centroid of the Local Group of galaxies. Observations of faint sporadic meteors with FAVOR TV CCD camera confirmed the radiant at a higher than 96% confidence level. We conclude that this meteor particle is likely to be of extragalactic origin. The following important questions remain open: (1) How metal-rich dust particles came to be in the extragalactic space? (2) Why are the sizes of extragalactic particles larger by two orders of magnitude (and their masses greater by six orders of magnitude) than common interstellar dust grains in our Galaxy? (3) If extragalactic dust surrounds galaxies in the form of dust (or gas-and-dust) aureoles, can such formations now be observed using other observational techniques (IR observations aboard Spitzer satellite, etc.)? (4) If inhomogeneous extragalactic dust medium with the parameters mentioned above actually exists, does it show up in the form of irregularities on the cosmic microwave background (WMAP etc.)?

Gravitational focusing and shielding of meteoroid streams

The gravitational attraction of planets can cause significant perturbation of the trajectories of meteoroids. The resulting deflection can result in significant enhancement of the flux of meteoric particles in the neighbourhood of the planet. We give an analytical method for calculating the relative flux of stream meteoroids in the vicinity of a planet. We include the effect of shielding of certain regions that are not accessible to the meteoroids that have impacted the planet. We compare our results with those of Divine et al. and although we confirm the accuracy of their trajectory equations, the fluxes predicted by their calculations are not consistent with integrated fluxes over a planet predicted by the classic work of Opik. Our method yields predictions for the integrated flux enhancement factor that are identical to Opik's. We present the results of these calculations and find that in all cases, tail-like regions of enhanced meteoroid flux appear downstream of the planet, with very large enhancements possible in the case of the giant planets for all probable stream velocities.

Impact of the Ablation of Micro Meteoric Particle on the Metallic Layer in Mesosphere

采用连续的微流星体消融模型,对小微粒的流星颗粒(半径＜100 μm)消融过程进行分析,并估计对中高层区域(80～110 km)金属层的影响.无线电流星雷达与激光雷达的探测结果表明,半径在100 μm以上的流星颗粒的消融物并不是金属层主要的源.本文从流星颗粒的动量方程和能量方程出发,计算不同半径下的流星微粒在不同的注入速度下的消融剖面,并分析了流星消融截止高度的变化趋势.结合长期的激光雷达观测,计算表明,10～40 μm半径的流星微粒是普通金属层的主要影响因素.