Meteoric Phenomena Research Articles

Geophysical Observations of the 2023 September 24 OSIRIS-REx Sample Return Capsule Reentry

Sample return capsules (SRCs) entering Earth’s atmosphere at hypervelocity from interplanetary space are a valuable resource for studying meteor phenomena. The 2023 September 24 arrival of the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer SRC provided an unprecedented chance for geophysical observations of a well-characterized source with known parameters, including timing and trajectory. A collaborative effort involving researchers from 16 institutions executed a carefully planned geophysical observational campaign at strategically chosen locations, deploying over 400 ground-based sensors encompassing infrasound, seismic, distributed acoustic sensing, and Global Positioning System technologies. Additionally, balloons equipped with infrasound sensors were launched to capture signals at higher altitudes. This campaign (the largest of its kind so far) yielded a wealth of invaluable data anticipated to fuel scientific inquiry for years to come. The success of the observational campaign is evidenced by the near-universal detection of signals across instruments, both proximal and distal. This paper presents a comprehensive overview of the collective scientific effort, field deployment, and preliminary findings. The early findings have the potential to inform future space missions and terrestrial campaigns, contributing to our understanding of meteoroid interactions with planetary atmospheres. Furthermore, the data set collected during this campaign will improve entry and propagation models and augment the study of atmospheric dynamics and shock phenomena generated by meteoroids and similar sources.

KINEMATIC PARAMETERS, PHYSICAL CHARACTERISTICS, AND CHEMICAL COMPOSITION OF SELECTED METEOR BODIES

Background. Meteoroids can reach the Earth and penetrate its atmosphere creating meteor phenomena. Kinematic parameters, physical characteristics, and chemical compositions of the observed meteor bodies provide information about the properties of their parent bodies — comets and asteroids. On the other hand, these parameters can reflect the physical conditions of meteor- oids staying in different parts of the Solar System and beyond. Methods. The meteor data analyzed in this work were obtained from observations using the automatical video and spectral meteor patrol (AVSMP) of the Institute of Astronomy of V. N. Karazin Kharkiv National University. The methods of meteor astronomy and spectroscopy make it possible to determine the kinematic parameters, physical properties, and chemical com- position of the meteoroids that we studied. Results. The paper presents the research results of meteors brighter than 0m that were recorded by the multi-stations method. These meteors also have spectral observations. For the selected 12 meteors, we obtained the coordinates of meteor radiants on the celestial sphere, the parameters of the atmospheric trajectories of meteor bodies, and the heliocentric orbital parameters of the observed meteoroids for the epoch (J2000). The extra-atmospheric masses of meteoroids were determined from photometric data. The identified emission lines detected in meteor spectra were analyzed. The software developed by the authors of this paper for me- teor spectra processing was used. Qualitative and quantitative analyses of the chemical composition of meteor bodies were carried out. During the quantitative analysis, the values of the relative intensities of the Fe I-15, Mg I-2, and Na I-1 lines were determined. Conclusions. Kinematic parameters and elements of heliocentric orbits presented in this work indicate that the observed me- teor bodies belong to meteor showers and their comets, such as Perseids, Leonids, and Southern Taurids. Some meteor bodies are sporadic. The calculated masses of meteoroids have some scatter of values, but they are generally consistent with observa- tions of other authors in the range of absolute values of the meteor brightness -2m…+1.5m. It was found that some of the studied meteor bodies are Fe-poor or Na-poor in their chemical composition.

ON THE POSSIBILITY OF THE AGROGLYPHS EMERGENCE UNDER THE INFLUENCE OF COSMIC FACTORS

Based on the study of the phenomenon of wheat stalks regular lodging on a large area (Voznesenovsky phenomenon), the possibility of linking this and other similar phenomena (agroglyphs) of natural origin with the action of cosmic factors is analyzed. The criteria features of the phenomena under consideration and particular structural features of the phenomenon under study are determined. It is shown that in order to explain the totality of facts, the most promising is to attract the idea of a short–term radiation effect of sufficiently high energy on the entire plant array. This point of view is quite consistent with the features of the structure and physiology of cereal crops stems. The reason for the wheat stalks lodging could be the heating of their nodes under the action of a pulse of microwave radiation. The preference for microwave radiation, but not infrared radiation, is physically justified. The supposed source of the microwave radiation pulse is the development of a meteor phenomenon generated by the intrusion into the Earth's atmosphere of a meteor body containing a significant mass of water ice. The paper shows that in this case, one can expect the appearance of a pulse of forced (maser–type) radiation at a wavelength of 1,35 cm. This radiation can reach the Earth's surface quite freely. Calculations of the energy and mass of a meteor body, which capable to generat the considered effect, are in good agreement with the data of meteor astronomy. Orderliness in the lodging of stems is explained from the standpoint of heliotropism of plant development. The general aspects of the agroglyphs appearance connection with the manifestations of meteoric activity and the prospects for the development of the study are discussed.

Daily distribution of meteor flight frequency according to radio observations

The paper considers the problem of studying the daily distribution of the passage of meteoroids by radio observation. The advantages of the chosen method of registration over the classical optical and photographic methods of observation are considered. A voluminous series of data was obtained using a registration facility implemented on the basis of the Center for Astrophysical Research at the North Kazakhstan University named after Manash Kozybayev. Processing, analysis and systematization of the obtained data on meteor phenomena have been carried out. Based on the obtained observational data, on the basis of the Center for Astrophysical Research at the North Kazakhstan University named after Manash Kozybayev, using the Multi VirAnalyzer program, namely the Date Recorder, the daily distribution of the meteor flight frequency was calculated. Also, with the help of the Microsoft Excel software application, diagrams of the daily distribution of the meteor passage frequency were constructed. During the analysis of the obtained diagrams of the daily distribution of the meteor passage frequency, the peak and average daily values of meteor activity were determined. Based on the daily distribution, diagrams of the frequency of meteor passages were constructed for certain months during which the Perseid and Leonid meteor showers are active. A clear correlation with the results of studies of other laboratories of a similar line of research is shown.

Physical bases of meteor registration methods and the instrument complex of the NKU Observatory

One of the actual directions of studying the physical characteristics of near–Earth space is the assessment of the concentration of meteoroids in it, and the time change of this parameter. In this regard, the principles of setting and implementing meteor observations at the observatory of the North Kazakhstan university named after Manash Kozybayev are considered in chronological order. Meteor observations were carried out on the basis of an integrated approach, including the use of meteor patrols, an All Sky camera, a system for recording radio wave reflections from a remote station from meteor tracks, and a camera based on an optical image intensifier.  Based on the analysis of the practical experience of using this equipment, the advantages and disadvantages of each of the methods of meteor registration are revealed. It is shown that the use of the latest image brightness amplifiers and wide–angle cameras with the highest possible sensor sensitivity is the most progressive for their optical observations. The closest attention is paid to the analysis of the experience of implementing the registration of plasma meteor tracks in the radio range. The method is based on the selection of reflected (scattered) musical–speech signals of a remote radio station having a specific pulse structure. Comparison of the obtained results on the frequency of meteor phenomena with the data of known observation points allows us to speak about the effective operation of the newly created meteor monitoring system in the radio range. In the final part of the work, ways to improve the efficiency of recording meteor phenomena in the optical range based on the use of the latest radiation receivers are considered.

Single-station meteor detection filtering using machine learning on MOROI data

ABSTRACT Nowadays, extensive data are collected in an automated regime. Combining this, with the increase in accessible computational power, led to large-scale implementations of machine learning (ML). This is also the case of meteor science, where object detection often requires tracking of a moving light source between frames, and the number of false positives can be up to an order of magnitude higher than true meteoric phenomena. While spatiotemporal coincidence of events recorded by close, multiple cameras can eliminate most of the false positives, single-station detections in some camera networks are currently discarded. In this paper, we explore a set of ML models aiming to find an optimal method for re-analysis of this single-station observations, in order to identify and extract real meteors. A set of 15 ML models were trained on features extracted from the meteor movement. Upon testing, we found a top accuracy score of 98,2 per cent, and a recall (i.e. percentage of meteors correctly classified) score of 96 per cent for the best performing models. When combined with the spatiotemporal coincidence of the detection, the recall increases to 99.92 per cent. These 15 ML techniques were selected according to their ability classify tabular data, hence the bundle can be applied to other studies. The same goes for the computed features, which are independent on the camera configuration, thus, the process can be scaled and applied to other networks. These methods are to be implemented to re-analyze the events recorded by the larger, FRIPON network.

Characterization of the Fireballs Detected by All-sky Cameras in Romania

Some of the fields of research that have captured the persistent interest of both scientists and the general public are meteor phenomena. The main goal in the study of meteoroid impacts into Earth’s atmosphere is the recovery of the remnant matter after the ablation in the form of meteorites. This is a complementary approach, yet cheap alternative, to a sample return mission. Meteoroids are messengers since the time of the formation of the solar system due to the fact that they have preserved the same composition. The study of meteorites provides information regarding the chemical composition from which the planets formed. The increasing number of all-sky camera networks in recent years has resulted in a large set of events available for study. Thus, it is very important to use a method that determines whether the meteoroid could produce a meteorite or not. In this paper we study the meteors detected by the FRIPON network in Romania with the use of all-sky cameras. We focus on the events with noticeable deceleration (V f /V 0 < 0.8). We determine the ballistic coefficient α and the mass-loss parameter β for the selected sample. Based on this analysis the events are classified in three categories: (1) meteoroids that are likely to produce meteorites; (2) meteoroids that can possibly produce meteorites; (3) meteoroids that are unlikely to produce meteorites. The entry and final mass are determined for each event. From the recorded fireballs, we identified one possible meteorite dropper, and we analyzed its dynamical evolution.

TALES FROM INDIA. 1: METEOR SHOWERS IN CLASSICAL AND COLONIAL SOURCES

Meteor phenomena are always fascinating and capture popular attention. This paper reports results of a search for references to and records of meteor showers observed in the Indian region, until the close of the nineteenth century. The sources explored were the Indian classics and chronicles, institutional reports and accounts by individuals, including those published in professional journals. We found very few references to such events in the classical sources. The earliest datable references that we found were in Shuka's <italic>Rajatarangini</italic> (Perseids or Leonids, 1533), Abu'l Fazl's <italic>Akbarnama</italic> (Alpha Capricornids or Delta Aquarids, 1592) and in Krishnaji Sabhasad's account of the life of Chhatrapati Shivaji Maharaj (Leonids, 1680). The subsequent accounts belong to the nineteenth century. Some of these are about sporadic meteors, while others are about meteor showers. The earliest published report is of the November Leonid meteor shower of 1832. We also came across a strong meteor shower on 10 September 1841 reported in the 13 September issue of the <italic>Englishman</italic> newspaper. We believe this is the September Epsilon Perseids, a minor shower known to peak on 9/10 September. This 1841 observation is 37 years before the September Epsilon Perseids were first described by William Denning, in 1878. We believe that such records can be of great value in fine-tuning time-lines in Indian history and understanding the dynamics of meteoroid streams.

Метеори - основни понятия и терминология – II част

This article discusses some basic concepts related to meteor astronomy, as well as the use of the correct terminology when working in Bulgarian. Due to the huge volume of topics, this is the second part of an upcoming series that examines only the most general principles in meteor science. The article can serve the public observatories and similar structures related to the teaching of amateur astronomy (due to the lack of such literature in Bulgarian), and meteor phenomena will continue to attract the attention of a wide range of people, giving them mostly a strong , emotional impact!

Novel Meteor Observations Using FM Radio Broadcast Over Gadanki, India

A novel GNU radio-based software-defined radio receiver using USRP (universal serial radio peripheral) front end and YAGI antenna is developed to record meteor echoes in passive mode using FM broadcast. Pilot observations are made for four days in August-September 2020 to record FM signals at 103.2MHz, 104MHz, and 107.5 MHz with a varying sample rate of 8 KHz and 200 KHz. The in-phase and quadrature signals are processed to obtain the amplitude and phase of the received signals for identification of the meteor echoes. A new algorithm is developed to automatically detect the echoes using a normalized amplitude threshold and a minimum temporal separation between two echoes. Overdense meteor echoes with a plateau-like amplitude response are found using a ratio test and remaining echoes are rejected. Thus, the system is able to detect almost all types of meteor echoes reported earlier. Notably, signatures of fragmentation and background wind are also observed in form of different phase patterns. Histogram of the meteor counts shows a peak for shorter durations indicating larger populations of the smaller size of meteoroids. The log-log plot of the meteor duration versus count is found to exhibit a characteristic transition of the slope. An empirical estimate of the height of the echoes is obtained. The echoes show micro-meteoroid populations which may depend upon the transmitting-receiving setup and the geometry. Hence, an inexpensive, low-power, portable, passive and automated meteor detection system is demonstrated which can be highly useful for understanding the meteor phenomena and estimation of atmospheric parameters.

Метеори - основни понятия и терминология

This article discusses some basic concepts related to meteor astronomy, as well as the use of the correct terminology when working in Bulgarian. Due to the huge volume of topics, this is the first part of an upcoming series that examines only the most general principles in meteor science. The article can serve the public observatories and similar structures related to the teaching of amateur astronomy (due to the lack of such literature in Bulgarian), and meteor phenomena will continue to attract the attention of a wide range of people, giving them mostly a strong, emotional impact!

Review of synergic meteor observations: linking the results from cameras, ionosondes, infrasound and seismic detectors

ABSTRACT The joint evaluation of different meteor observation types supports a better understanding of both meteor phenomena and the terrestrial atmosphere. Two types of examples are presented in this work, linking ionospheric effects to specific meteors, with almost one-third of the meteors that emerged at high altitudes simultaneously recorded with an optical camera. Very few such observations have been realized as yet. With daytime fireballs, the recorded infrasound effect and the atmospheric blast produced shock-wave-related small earthquakes which were identified by a network of ground stations. An overview of these observational types highlights specific topics for which substantial improvements and discoveries are expected in the near future.

Становлення та розвиток Української мережі радіоспостережень метеорів

During the decade of research, the Research Institute “Mykolaiv Astronomical Observatory” (RI “MAO”) developed hardware and software for monitoring, extracting, and calculating the parameters of meteor phenomena using the forward scattering by meteor ionized trail of the signals of over-the-horizon FM-stations broadcasted in the frequency range of 88—108 MHz. This allowed creating a network of observations of meteor phenomena in the radio range, which consists of six stations located in Mykolaiv (three stations), Rivne, Lviv, and Hlukhiv. The stations have identical hardware and software. Yagi-Uda antennas with six or eight horizontal vibrators and SDR receivers based at RTR2832U microchip are used to receive radio signals. The station software performs continuous registration and analysis of received radio signals at the output of quadrature detectors of the receivers, automatic detection of moments of appearances of meteor reflections, formation, and sending by e-mail daily reports on detected meteor phenomena. Equipment setup and current monitoring of stations operations are carried out by the RI «MAO» using remote access to station computers via the Internet. Monthly reports on the number of meteor events recorded by each station are posted on the site of Radio Meteor Observation Bulletin (RMOB). The article presents the results, obtained by the network in 2017—2019, confirming a correspondence of daily variations in the number of meteors registered by network stations, to the known dependence (observation of meteors in the apex and antapex), as well as a correspondence between the expected characteristics (in time and intensity) of three meteor showers (Perseids, Geminids and Quadrantids) and that had been obtained by the network. Recommendations are also given in the article for additional research aimed at achieving the main goal, namely, expanding information about meteor phenomena, including the estimating of kinematic parameters (velocities, radiants) of meteoroids and their relationship with potentially hazardous asteroids.

Plasma Modeling and Prebiotic Chemistry: A Review of the State-of-the-Art and Perspectives.

We review the recent progress in the modeling of plasmas or ionized gases, with compositions compatible with that of primordial atmospheres. The plasma kinetics involves elementary processes by which free electrons ultimately activate weakly reactive molecules, such as carbon dioxide or methane, thereby potentially starting prebiotic reaction chains. These processes include electron–molecule reactions and energy exchanges between molecules. They are basic processes, for example, in the famous Miller-Urey experiment, and become relevant in any prebiotic scenario where the primordial atmosphere is significantly ionized by electrical activity, photoionization or meteor phenomena. The kinetics of plasma displays remarkable complexity due to the non-equilibrium features of the energy distributions involved. In particular, we argue that two concepts developed by the plasma modeling community, the electron velocity distribution function and the vibrational distribution function, may unlock much new information and provide insight into prebiotic processes initiated by electron–molecule collisions.

Resolving the ambiguous direction of arrival of weak meteor radar trail echoes

Abstract. Meteor phenomena cause ionized plasmas that can be roughly divided into two distinctly different regimes: a dense and transient plasma region co-moving with the ablating meteoroid and a trail of diffusing plasma left in the atmosphere and moving with the neutral wind. Interferometric radar systems are used to observe the meteor trails and determine their positions and drift velocities. Depending on the spatial configuration of the receiving antennas and their individual gain patterns, the voltage response can be the same for several different plane wave directions of arrival (DOAs), thereby making it impossible to determine the correct direction. A low signal-to-noise ratio (SNR) can create the same effect probabilistically even if the system contains no theoretical ambiguities. Such is the case for the standard meteor trail echo data products of the Sodankylä Geophysical Observatory SKiYMET all-sky interferometric meteor radar. Meteor trails drift slowly enough in the atmosphere and allow for temporal integration, while meteor head echo targets move too fast. Temporal integration is a common method to increase the SNR of radar signals. For meteor head echoes, we instead propose to use direct Monte Carlo (DMC) simulations to validate DOA measurements. We have implemented two separate temporal integration methods and applied them to 2222 events measured by the Sodankylä meteor radar to simultaneously test the usefulness of such DMC simulations on cases where temporal integration is possible, validate the temporal integration methods, and resolve the ambiguous SKiYMET data products. The two methods are the temporal integration of the signal spatial correlations and matched-filter integration of the individual radar channel signals. The results are compared to Bayesian inference using the DMC simulations and the standard SkiYMET data products. In the examined data set, ∼ 13 % of the events were indicated as ambiguous. Out of these, ∼ 13 % contained anomalous signals. In ∼ 95 % of all ambiguous cases with a nominal signal, the three methods found one and the same output DOA, which was also listed as one of the ambiguous possibilities in the SkiYMET analysis. In all unambiguous cases, the results from all methods concurred.

Experience of registration of reflection of radio signals from plasma meteor tracks in the observatory of SKSU

One of the actual problems of astrophysical studies of The solar system bodies is the registration of meteor phenomena occurring in the upper layers of The earth’s atmosphere. Statistics of such events allow to obtain averaged estimates of the concentration of meteoroids in near-earth space. These data have an important practical application on the security of space infrastructure development. In this paper, it is shown that optical methods of meteor registration, despite their diversity, suffer from limitations associated with the influence of atmospheric meteorology, daylight and anthropogenic illumination of the sky. In this regard, the transition to the use of methods of registration of meteors based on the property of formed or plasma tracks to reflect radio waves is relevant.The results of work on the development of the material base and methods of radio observations of meteors in the center of astrophysical research of North Kazakhstan state University are presented. The approach of registration of the radio signal reflected from the plasma meteor track of the remote station is applied. Information processing was carried out online using standard software. Comparison of the obtained results with the published data on the application of the method showed a high degree of similarity of the amplitude-time structure of the signal with typical for the applied&nbsp;method. The daily frequency distribution of meteor events is also quite realistic. Thus, we can state the creation in the Republic of Kazakhstan of the first point for registration of meteors in the radio range.

Development of meteor astronomy at the Odessa University during the period of Ukraine's independence

The article using the methods of bibliographic and source study analysis and systems approach highlights the state and main trends in the development of meteor astronomy in Odessa during the time of independent Ukraine. At the beginning of the 21st century, continuous meteor patrol was restored at the Odessa Astronomical Observatory, which was intensively conducted at the Observatory during Soviet times. It was based on the use of the television and telescopic method, which was used in the CIS for the first time. The advantages of using the television telescopic method in comparison with the photographic and radar methods for solving the fundamental problems of meteor astronomy are noted. The text gives valuable information on the features of continuous meteor patrols at the observation station Kryzhanovka and the work of the expeditionary automatic meteor patrol on Snake Island (Odessa region, Ukraine). The methods of conducting telescopic television observations and processing observational material developed by Odessa researchers are considered. The main directions of meteoric studies conducted in the Odessa Astronomical Observatory using television meteor patrol materials were determined. Studying the physics of meteoric phenomena, obtaining exact coordinates of individual meteor radiant, spectral observations of meteors, studying double and multiple meteors, studying the structure and density of meteoric dust particles, solving interaction problems meteor showers with the Earth’s atmosphere, statistics of meteor phenomena in the Earth’s atmosphere are the main directions of meteoric studies of Odessa Astronomical Observatory. The scientific potential of Yu. M. Gorbanev in the field of meteor astronomy of, the leader of the meteoric group, O. V. Holubaieva, the head of the meteor's television patrol at the Kryzhanovka observation station in 2003-2011, as well as participation in the meteor research S. H. Kimakovskyi, I. I. Kimakovskyi, S. V. Podlesniak, I. A. Stognieieva, L. A. Saresta, A. F. Prinzykov, V. A. Shestopalov, etc are noted. Conclusions are drawn about the importance of conducting meteoric research for the development of fundamental and applied science.

Construction of a meteor orbit calculation system for comprehensive meteor observation at Kochi University of Technology

The development of a Ham-band Radio meteor Observation (HRO) Interferometer (IF) at Kochi University of Technology began in 2003. Meteor orbit calculation system uses multi-site radio observation with global positioning system (GPS) timing combined with 5 channel (5 ch) interferometer. The HRO-IF utilizes forward-scattering of 53.750 MHz continuous radio waves transmitted from the Sabae station, realized in 2012. Since the last development, the observation data has been used to study the upper atmosphere from the meteor phenomenon. Here, we introduce the results of the 2015 Geminid meteor shower recorded by forward-scatter multi-site observations as a low-cost and low-power 24/7 continuous meteor observation system, as well as the concept of a comprehensive radio meteor orbit calculation system. As a result, 20 examples of Geminid meteor shower events with 3 levels of noise signal classification recorded in our observations. The predicted Geminid meteor shower speed is about 34 ± 8.86 km/s based on the average value of 12 meteor shower data group in the minimum noise signal category (class A).

Progress of Radar Observations of Meteors in Kazan (Russia) over the Last Sixty Years

AbstractThis paper presents a brief survey on the history of radar observations of meteors in Kazan from 1950s to present days. Such achievements of Kazan researchers as development and further improvement of original measuring equipment and antenna systems, of observational data processing methods, their contribution to the theory of physics of meteor phenomena and theoretical interpretation of experimental data are highlighted. A particular progress in meteor astronomy has been achieved with a new discrete quasi-tomoghraphic method for faint meteor showers identification that uses goniometer data of meteor radio reflections detected on radar as input data. The current state and new horizons of meteor studies in Kazan are stated.

Assessing the meteoroid risk in near earth space

Abstract The meteoroid risk in circumterrestrial space is basically caused by 1-10 mm meteoroid bodies. Meteoroid particles of such dimensions cannot be registered by modern monitoring astronomical instruments. Observable are only meteor phenomena they cause. This work analyses the activity of main meteor showers over several years and assesses the danger from meteoroids with a size of more than 1 mm. The results of calculating the meteoroid risk during these showers’ maximum activity periods have shown that despite its low values it is sufficiently close to the maximum allowable risk. This already constitutes a recognizable danger, and such a danger needs to be taken into consideration.