Abstract We report the successful detection of the Arid meteor shower (IAU#1130 ARD), predicted to emerge for the first time in 2021, using a publicly accessible YouTube live camera developed by us. This live camera, installed on the Subaru Telescope dome in the summit region of Maunakea, Hawai’i, features a wide field of view ($70^{\circ } \times 40^{\circ }$) and high sensitivity, and is capable of observing stars fainter than the sixth magnitude. Meteor detection was performed in two ways: visual inspection by citizen viewers and subsequent validation through automated detection. As a result, we confirmed that the number of meteors appearing from near the predicted radiant increased by more than six times (${\sim }9\, \sigma$) compared to the preceding and following days. Our observation time was 4–5 h after the predicted peak (solar longitude = ${193^{\circ}_{.}9}$), providing clear data indicating that the activity had not yet declined. Optical observations at this time from the Northern hemisphere are extremely limited and unique, making our observation point valuable. The meteors are characterized by their slow and faint appearance, but several brighter meteors with wakes were also observed. Simulations tracing the dust trails from the parent body, Comet 15P/Finlay, suggest that our detection can be explained by either of the dust trails released in 2008 or 2014, both requiring high ejection velocities. However, during the comet’s 2008 return, its activity was exceptionally quiet, making a high-velocity dust ejection questionable. On the other hand, multiple large outbursts were observed during the 2014 return, at which time a certain amount of high-velocity dust release is expected. We conclude that the dust source of the meteor shower detected in Hawai’i this time is likely attributable to high-velocity ($\sim$67 m s$^{-1}$) dust ejected during the 2014 outburst.

Geminids have the highest bulk density of all major meteor showers and their mechanical strength appears to depend on their mass. They are also the most active annual shower, enabling detailed studies of the dependence of their physical and mechanical properties on mass. We calculated the fragmentation cascades of 39 bright Geminid fireballs, as well as faint video meteors, to derive fragmentation pressures and other physical properties characterizing the meteoroids, such as their bulk densities. Our goal is to describe the mechanical properties across a broad range of initial masses and explain the cause of the observed behavior. We used a physical fragmentation model with a semiautomatic method based on parallel genetic algorithms to fit the radiometric and regular light curve and dynamics data. We also calculated the thermal stress of model bodies with the type of physical properties and trajectories as the observed Geminids. Then, we compared the outcomes of these simulations to our observations. We find that the Geminids are probably cracked by thermal stress in the atmosphere first and then eroded by mechanical forces. The most compact Geminids are in the 20 200, mass range. The largest observed meteoroids have a wide range of grain sizes, from about 20, - g m to large, non-fragmenting parts of 1 20, in size. The derived bulk densities range from about 1400 to 2800, for smaller meteoroids and approach the assumed grain density of 3000, for larger Geminids. - mm -3 -3

This article considers the poetic semantics of words and phrases related to the designation and conventional explanation of summer lightnings (flashes without thunder) in Russian and several Finno-Ugric languages (Mari, Komi, Udmurt). Based on dialect linguistic materials and Russian folklore texts (songs, ditties (chastushki), omens) and the facts of Finno-Ugric speech (idioms, proverbs), the authors analyse mythological and artistic meanings of certain figurative motifs related to astral phenomena (meteor shower, light, lightings). The work aims at analysing linguistic facts and folklore motifs showing how the peculiarities of natural phenomena perception that are universal or specific for certain people are reflected in the studied cosmic images and in the definition of typological similarity between figurative cosmonyms and their modifications in different languages and cultures. For example, it shows the transformation of plots with the characteristics of autumn meteor showers in cultures with developed agricultural and hunting-trade traditions. The authors examine the development and linguistic functioning of imagery plots defined by tradition that express complex psychological human conditions related to several existential notions (life, love and death, destiny). They describe the meaning of astral images in the artistic texts and individual styles of Viktor Astafyev, Vasily Klimov, and other authors. Conclusions are drawn about the variety of linguistic ways of the verbalisation of the “зарница” mythologeme in popular speech and the active realisation of its pictorial potential in folklore and artistic texts.

Abstract Several researchers predicted an outburst of the October Draconids in 2018, with the peak expected between 23:43 UT on October 8 and 00:14 UT on October 9. We observed the event from Husafell, Iceland, where conditions were favorable during the predicted peak time. As a result, we detected the appearance of a more active shower than expected. Three peaks were identified in the time variation of the meteor activity. The main peak occurred at 23:43 UT on October 8, with the estimated hourly rate (HR) reaching 54. This corresponds to a meteor flux of $9.9 \times 10^{-3}\, \mathrm{km^{-2}\, h^{-1}}$ for meteors brighter than +3.5 mag. Two additional sub-peaks were observed at 00:28 and 01:08 UT on October 9. The presence of three distinct peaks suggests a complex structure within the dust trail system. In addition to the main CCD observations, we also employed a complementary observation using a mirrorless digital camera with a high-sensitivity CMOS sensor. The resulting flux values agreed well with those from the CCD system, suggesting that such mirrorless setups may now offer a practical alternative for observing faint meteors.

Improved measurement of radar meteor shower mass indices

The given article describes the improved model for analytical computation of the probability of Earth’s satellite collision with particles of meteor streams. An original statistical approach is proposed. Depending on the mass of the meteoroid, its velocity, angle of attack, and the physical characteristics of the impactor (space particle) and the target (satellite), the degree of potential damage to the spacecraft, such as depressurization or erosion of its casing, especially solar panels, is determined. To describe the formation of an explosive crater due to a collision, the Öpic theory of meteor crater formation was used, which has been repeatedly tested and has given good results. The theoretically calculated depth of the crater on the surface of the spacecraft was chosen as the criterion for the degree of damage, and damage was considered to be encounters with particles that leave craters 0.2 cm deep, which at a normal angle of attack and a speed of 30 km/s, with an iron casing of the satellite, gives a diameter of a stone meteoroid of 0.19 cm and a mass of 0.013 g. The masses of particles that lead to erosion of the casing are several orders of magnitude smaller. To plot the influx of sporadic meteors to Earth (or the flux of particles in orbit), a cumulative distribution was chosen, defined for the mass range from 0.000001 to 100 g. This distribution was used to calculate the influx from meteor shower particles through the zenith hourly rates of the streams and the sporadic background. For certainty, the most powerful meteor showers were taken into account — eight in total: Lyrids, h-Aquariids, Southern d-Aquariids, Perseids, Orionids, Leonids, Geminids, and Quadrantids. Additionally, the model calculated the time of screening a satellite in a given orbit from stream meteoroids by a planet and its atmosphere. To calculate the effective surface area of a satellite for the direction of the meteor stream, an analytical model of the satellite composition from three-dimensional geometric primitives is proposed. Unfortunate- ly, its use is limited when there is a significant degree of screenization of one geometric primitive by another; in this case, it is proposed to use a numerical approach. As an example, an estimate of the probability of damage to a hypothetical spacecraft with a maximum effective area of about 8 square meters over the course of a year is given. It was 0.00002 for meteor showers, which is about four times less than the impact of the sporadic meteor background.

Abstract This study presents observational results of the 2022 outburst of the $\tau$-Herculid meteor shower. The event is attributed to a dust trail released during the 1995 fragmentation of its parent body, comet 73P/Schwassmann–Wachmann 3. Observations were carried out at the Goat Mountain Astronomical Research Station (GMARS) in California, where favorable conditions coincided with the predicted peak time. The outburst was also captured by a live camera located at the Subaru Telescope site on Maunakea, Hawai’i.At GMARS, video observations detected a peak at 04:46 UT on May 31, with the (Z) hourly rate (i.e., the hourly rate corrected for radiant altitude by applying a zenith attraction correction) reaching $173 \pm 26$. The corresponding flux was estimated to be $(6.1 \pm 0.95) \times 10^{-3}$ km$^{-2}$ s$^{-1}$. A gradual decline in activity was recorded at Maunakea after the peak, confirming the absence of any major secondary maxima. The observed timing and temporal profile of the activity agree well with predictions based on dust trail modeling, suggesting the detection of relatively large meteoroids ejected at a large negative velocity of approximately -27 m s$^{-1}$. Additionally, weak activity observed at Maunakea on the nights before and after the main peak implies the presence of more broadly dispersed dust trails originating from older ejection epochs. These findings support the conclusion that the 1995 outburst of the parent comet was a large-scale event that significantly contributed to the observed meteor activity.

Abstract The October Draconid meteor shower, produced by comet 21P/Giacobini—Zinner, is notorious for rare but intense outbursts, some exceeding rates of ∼104 meteors per hour. In 2025, Earth will encounter young trails ejected by the comet in 2005 and 2012, producing a meteor outburst and providing a rare opportunity to probe their structure and benchmark meteoroid stream models. We present predictions from three independent dynamical models (NIMS, MSFC, Sisyphus), calibrated against updated activity profiles including the newly observed 2019 and 2024 outbursts. All simulations predict enhanced activity on 2025 October 8, dominated by faint meteors (m < 10−5 kg; +4 mag and fainter) primarily detectable by radar. Our best estimate is a radar outburst near 15:00—16:00 UT, driven mainly by the 2012 trail with a possible minor contribution from 2005. The 2025 Draconids may represent one of the strongest radar dominated outbursts of the decade. Coordinated observing campaigns, especially radar measurements across the Northern Hemisphere and optical coverage from Asia, will be essential to validate these forecasts, constrain the dust environment of comet 21P, and improve future predictions of young meteoroid trails.

Abstract Meteor radio afterglows (MRAs) and optical persistent trains (PTs) are two types of long‐lived phenomena which are occasionally observed following the occurrence of a meteor. Both phenomena are thought to be produced by intrinsic emission mechanisms; PTs have been associated with chemiluminescent reactions between meteoric metals and atmospheric ozone whereas MRA emission arises due to radiation emitted by processes in the meteor's plasma trail. Previous research has identified an association between these phenomena, and proposed a mechanism by which the reactions responsible for PTs could also fuel MRAs. In this work, we investigate said connection using a substantially larger catalog containing hundreds of examples of each phenomenon. Using meteor data from the Global Meteor Network (GMN), we performed a directed search in all‐sky radio images obtained by the Long Wavelength Array (LWA) radio telescope to identify meteors with MRAs. The resulting catalog spanned nearly 2 years and contained a total of 2,887 meteors, with 675 MRA events and 372 PTs. Statistical analyses suggest that the connection between the two phenomena is not as strong as previously supposed. Additionally, we show that the MRA occurrence rates do not have a strong seasonal dependence, meteoroid strength dependence, or preference between meteor showers and sporadics. Interestingly, we find that a meteor's entry angle appears to play a significant role in whether an MRA is observed.

Comparison of meteor shower observed by two collocated meteor radars at low latitudes

Abstract Accurate identification of meteoroid streams is central to understanding their origins and evolution. However, overlapping clusters and background noise hinder classification, an issue amplified for missions such as the European Space Agency’s Lunar Meteoroid Impact Observer that rely on meteor shower observations to infer lunar meteoroid impact parameters. This study evaluates the performance of the Hierarchical Density-Based Spatial Clustering of Applications with Noise (HDBSCAN) algorithm for unsupervised meteoroid stream identification, comparing its outcomes with the established Cameras for All-Sky Meteor Surveillance (CAMS) look-up table method. We analyze the CAMS Meteoroid Orbit Database v3.0 using three feature vectors: LUTAB (CAMS geocentric parameters), ORBIT (heliocentric orbital elements), and GEO (adapted geocentric parameters). HDBSCAN is applied with varying minimum cluster sizes and two cluster selection methods (eom and leaf). To align HDBSCAN clusters with CAMS classifications, the Hungarian algorithm determines the optimal mapping. Clustering performance is assessed via the Silhouette score, Normalized Mutual Information, and F1 score, with Principal Component Analysis further supporting the analysis. With the GEO vector, HDBSCAN confirms 39 meteoroid streams, 21 strongly aligning with CAMS. The ORBIT vector identifies 30 streams, 13 with high matching scores. Less active showers pose identification challenges. The eom method consistently yields superior performance and agreement with CAMS. Although HDBSCAN requires careful selection of the minimum cluster size, it delivers robust, internally consistent clusters and outperforms the look-up table method in statistical coherence. These results underscore HDBSCAN’s potential as a mathematically consistent alternative for meteoroid stream identification, although further validation is needed to assess physical validity.

Abstract The Subaru-Asahi StarCam is a high-sensitivity live-streaming camera for meteor observation, installed on the dome of the Subaru Telescope at the summit area of Maunakea, Hawai’i. Although it was originally intended as a way to share the Maunakea's night sky with the public, including the local Hawai’i community, the system quickly demonstrated its potential for scientific research, owing to its highly sensitive video capabilities and the exceptional fraction of clear nights at the site. The core of the StarCam system features a Sony FX3 camera body paired with an F1.4 wide-angle lens, offering a field of view of $70^\circ \times 40^\circ$. Leveraging a state-of-the-art, high-sensitivity CMOS sensor and a bright lens, the system is capable of capturing stars as faint as magnitude 8 in real-time, with an effective frame rate of 15–30 fps. Live streaming via YouTube began in 2021 April, and the feed is constantly monitored by more than a hundred viewers at any given nighttime. This has enabled the camera to be used not only for observing regular meteor showers but also for monitoring scientifically important phenomena such as fireballs or unexpected meteor outbursts. Notable scientific achievements include: (1) Detection of the new Arid meteor shower in 2021, (2) identification of a sub-peak activity in the $\gamma$-Perseid meteor shower (2021), (3) detection of the 2022 $\tau$-Herculid meteor shower outburst, (4) confirmation of the activity of the Andromedid meteor shower (2021), and (5) multiple detections of meteor cluster phenomena. We discuss the potential and the future scope of StarCam as an open-access, real-time data platform for citizen science in meteor observations.

Abstract Observations of the lunar exosphere provide valuable insights into dynamic processes affecting the Moon, such as meteoroid bombardment. The Chamberlain model was used to estimate the zenith column density and temperature of Na atoms on August 13/14, 2009 after the maximum of the Perseid meteor shower. The column density and temperature of Na atoms delivered to the lunar exosphere by slowly changing processes during the maximum of the Perseid meteor shower on August 12/13, 2009 are also estimated. Using the Chamberlain model and Monte Carlo simulations, expected ratios of line‐of‐sight column densities of Na atoms at three observed altitudes on August 12/13, 2009 are obtained. We attribute the heightened intensities of Na emission lines on August 12/13, 2009 to the onset of the third short‐term peak in Perseid activity predicted by celestial mechanics. The best agreement between observations and theoretical models is achieved with a theoretical temperature of 3000 K for impact‐produced Na atoms. This third peak of Perseids is estimated to have begun between 23:29 and 23:41 UT on August 12, 2009, lasting about 83 min, with a mass flux attributable to the Perseids ranging between 1.6 × 10−16 and 5 × 10−16 g cm−2 s−1. Additionally, depletion of Li content compared to Na content in the lunar exosphere is detected. We developed a model predicting Perseid meteoroid stream activity on the Moon, comparing it with performed spectral observations of the lunar exosphere. By modeling 25,000 years of comet 109P/Swift–Tuttle's orbits, we identified 175 cometary trails likely to have generated meteoroids near the Earth and the Moon during the Perseid 2009 meteor shower. Our results reveal annual maxima inducing filament trail structures, one of which aligned closely with the observed peak of the increased Na content in the lunar exosphere.

Context. The study of meteoroid streams reveals the full complexity of these structures. At present, there is no objective method of deciding whether the parameters of an observed stream represent a further solution to an already known object or whether they relate to a new discovery. As a result, the Meteor Data Center (MDC) database of the International Astronomical Union (IAU) contains duplicates and false duplicates of meteor showers. Aims. It is desirable to detect questionable cases and correct their status in the IAU MDC database, thereby contributing to the improvement of its content. Having the correct content in the database is important for its applications, such as when assessing the threat from meteoroids to Earth’s artificial satellites. Methods. In this work, we used two approaches to address the shortcomings in the shower data. In the first, the internal compatibility of geocentric and heliocentric parameters representing a given stream was verified. In the second, a comparison of two or more solutions of the same shower was made in as much detail as possible. We verified 56 streams identified in our earlier work as suspected cases of misclassification. Results. For 43 streams, misclassification was confirmed, and we provide a proposal to change their status in the MDC to autonomous. In the remaining 13 cases, we propose to leave their status unchanged. Conclusions. Although we do not consider it ‘definitive’, our study clearly shows that repeated misclassification of new meteor shower solutions has occurred in the past. Correction of these cases will significantly improve the content of the MDC database. As an additional product, based on the approach proposed in this and our earlier work, relevant procedures have been proposed. They are available on the MDC database website and will make it possible to compare new meteoroid data with the contents of the database, thereby avoiding errors in their classification.

A novel statistical approach for determining the radiant of shower meteor: A trajectory-free analysis

Abstract In 2024, Ďurišová et al. found that the meteor shower Phoenicids, IAU No. 254, code PHO, can originate in the nuclei of three comets, 46P/Wirtanen, 104P/Kowal 2, and 289P/Blanpain. The latter was suggested to be the parent body of the shower already in 1963 by Ridley. In this work, we model the meteoroid streams of all three comets and follow their dynamical evolution in course to reveal, which of the three comets is dynamically the most suitable parent body and if there is only a single parent or the stream might be fed with the particles released from more objects. It is a difficult task not only because these comets and particles released from them show an erratic dynamical evolution, but also because the Phoenicid shower is, according to the IAU Meteor Data Center List of Showers, currently represented by two significantly different solutions. We concluded that all three comets can contribute with the meteoroids to the Phoenicid stream. The dynamics of 289P’s stream is mostly appropriate to fit the Phoenicid-shower solution AdNo = 1, but the nucleus of this comet is too small to explain the estimated total mass of the stream. The Phoenicids either occurred due to some sudden, but short term outbursts of the particles from the 289P’s nucleus or the other two comets, especially 46P, are the further parent bodies. Our study also indicates that the recently discovered shower M2023-Y1 is most probably the third solution of the Phoenicids.

The Connection Between the April Chi Librids Meteor Shower and Near-Earth Asteroids

Abstract It is believed that dust formations above the lunar surface, manifested via sunlight scattering and detected in‐situ, are of too low density to pose threats to lunar missions. However, occasionally prolonged fading/kindling of the immersing/emerging stars near the lunar limb indicates much denser low‐altitude dust clouds. We performed statistical analysis of such abnormal stellar occultation events (ASOEs), found in the Lunar Occultation Archive. Specific dependence of their duration on selenographic position reveals an impact‐plume like shape of dust clouds and excludes visual illusions, terrestrial cloudiness, and double stars as causes of the observed starlight extinction. The probability of the long‐lasting ASOEs peaks during the Perseid meteor shower in August, confirming the impact‐related nature of most of the related dust clouds. At the same time, additional semi‐monthly periodicity of ASOEs points to a complementary mechanism of dust lifting due to, for example, lunar outgassing triggered by solar tides.

This article introduces an innovative meteor detection system that integrates high-speed photodiode detectors with traditional camera-based systems. The system employs four photodiodes to record changes in sky brightness at 100 Hz, enabling meteor detection and the observation of their dynamics. This technology serves as a valuable complement to existing imaging techniques, offering a cost-effective solution for measuring meteor ablation at frequencies beyond the capabilities of camera-based systems. We showcase findings from the Perseid meteor shower, demonstrating the potential of our system. Moreover, our system addresses the current limitations in meteor radiometry, where many existing instruments either remain in developmental stages or have not been validated with a substantial number of confirmed meteor events. Our approach successfully addresses these limitations, demonstrating effectiveness across multiple meteor events simultaneously recorded on video.

Context. To date, only a few meteor clusters have been instrumentally recorded. This means that every new detection is an important contribution to the understanding of these phenomena, which are thought to be evidence of the meteoroid fragmentation in the Solar System. Aims. On May 31 2022 at 6:48:55 UT, a cluster consisting of 52 meteors was detected within 8.5 seconds during a predicted outburst of the τ-Herculid meteor shower. The aim of this paper is to reconstruct the atmospheric trajectories of the meteors and use the collected information to deduce the origin of the cluster. Methods. The meteors were recorded by two video cameras during an airborne campaign. Due to only the single station observation, their trajectories were estimated under the assumption that they belonged to the meteor shower. The mutual positions of the fragments, together with their photometric masses, were used to model the processes leading to the formation of the cluster. Results. The physical properties of the cluster meteors are very similar to the properties of the τ-Herculids. This finding confirms the assumption of the shower membership used for the computation of atmospheric trajectories. This is the third cluster that we have studied in detail, but the first one in which we do not see the mass separation of the particles. The cluster is probably less than 2.5 days old, which is too short for such a complete mass separation. Such an age would imply disintegration due to thermal stress. However, we cannot rule out an age of only a few hours, which would allow for other fragmentation mechanisms.