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Abstract The physical composition and structure of meteoroids gives us insight into the formation processes of their parent asteroids and comets. The strength of and fundamental grain sizes in meteoroids tell us about the environment in which small solar system bodies formed, and the processes which built up these basic planetary building blocks. The structure of meteorites can be studied directly, but the set of objects which survive entry through the atmosphere is biased toward large, strong objects with slow encounter speeds. Fragile objects, small objects and objects with high relative speeds are very unlikely to survive impact with the atmosphere. Objects between 100 μm and 1 m, which are not strong enough to survive the ablation process, must be studied by radar or optical methods. Large meteoroids, which produce bright fireballs, are generally studied by investigating their compressive strength when they fragment, and their strength can also be inferred indirectly from their end heights. Fragmentation in faint meteors can be inferred from interference in radar observations, or observed directly with high-resolution optical systems. Meteor light curves, begin heights and time-evolving spectra can also be used to infer meteoroid structure. This paper presents a review of the meteor observation methods currently used to infer the structure and fragmentation of meteoroids in the millimeter to meter size range, and the current state of understanding these observations have given us. [ABSTRACT FROM AUTHOR]

Abstract We present simultaneous optical and radar observations of meteors observed over the Arecibo radar in Puerto Rico. These observations were obtained during ∼ 24 h of radar time over 3 different nights in May 2012. The radar was operating in a dual-frequency mode at 430 MHz (UHF) and 46.8 MHz (VHF). The optical observations were made at 41 frames per second with an Andor Electron Multiplying CCD camera with a field of view of ∼ 6°, enabling the determination of accurate horizontal meteor velocities and optical light curves. There are varying detection sensitivities of the 3 different techniques (2 radar, 1 optical). The UHF radar is the most sensitive, resulting in a total of 8710 detected meteors during that period, while the VHF radar is significantly less sensitive—resulting in only 278 detected meteors. The optical observations are the least sensitive, resulting in a total of 178 detections. Of all of these meteors, only 19 were simultaneously detected by the 3 instruments. This paper focuses on the analysis of these 19 common events. The meteoroid masses determined from the optical light curves were found to be in the range of 20 μ g to 1.2 mg and did not correlate with the maximum Signal-to-Noise Ratio (SNR) of either radar. In addition, the UHF radar detected 5 out of these 19 meteors with far side-lobes, beyond the main-beam and first side-lobe. This indicates that a significant fraction of events detected by the UHF radar could be in far side lobes and therefore have significantly underestimated Radar Cross Sections (RCS), given the smaller backscattered powers received in the side lobes. Highlights • Simultaneous meteors can be observed with optics and both radars at Arecibo. • The optically derived mass ranged from 20 micrograms to 1.2 mg. • Most optical meteors were detected by the side-lobes of the UHF radar. [ABSTRACT FROM AUTHOR]

Results are presented from a video-based meteoroid orbit survey conducted in New Zealand between Sept. 2014 and Dec. 2016, which netted 24,906 orbits from +5 to −5 magnitude meteors. 44 new southern hemisphere meteor showers are identified after combining this data with that of other video-based networks. Results are compared to showers reported from recent radar-based surveys. We find that video cameras and radar often see different showers and sometimes measure different semi-major axis distributions for the same meteoroid stream. For identifying showers in sparse daily orbit data, a shower look-up table of radiant position and speed as a function of time was created. This can replace the commonly used method of identifying showers from a set of mean orbital elements by using a discriminant criterion, which does not fully describe the distribution of meteor shower radiants over time. [ABSTRACT FROM AUTHOR]

An ablation model is used to describe the interaction of small meteoroids with the Earth's atmosphere. In this model, the mass loss of a meteoroid is determined using the saturated vapor pressure of the assumed meteoroid substance. The meteoroid is considered in two modifications as a solid and a porous object. An automated method for estimating the parameters of meteoroids (mass, size, and density) from light curves is developed based on the model of small meteor body ablation, which has been used to estimate the parameters of the Perseid meteors with a brightness of -2m to +2m. The influence of the dependence of the structure (solid/porous) on the parameters of the meteoric body is considered. The estimates of the mass of meteoroids using different model modifications are close to each other (the deviation is no more than 25%) and they coincide with the photometric mass of the meteoroid. The average porosity for all meteoroids is 72% and 84% depending on the model, which is close to the values for IDP. The density of meteoroids is determined with a large error. • A model describing the interaction of small meteoroids with the Earth's atmosphere is used to reproduce the light curves and to determine the parameters of meteoroids. • Model is applied to Perseid observations. • Meteoroid parameters were determined based on the light curve. • Fragmentation was not included in the current version of the model, although its role may be notable. [ABSTRACT FROM AUTHOR]

Meteor shower identification and search for parent bodies of the meteoroid streams are still on-going topics of meteor science. Both problems are often approached by comparing the orbital (and/or geocentric) parameters of the investigated bodies, as is done in the independent identification method developed by Rudawska et al. (2014). In our work we applied the slightly modified version of the method to 3 most numerous years of the EDMOND (The European viDeo MeteOr Network Database) meteor data, and identified 517 meteor showers. Found showers were characterized and the problematic cases of mis-identification and hyperbolic orbits were analysed. The newly determined mean orbital parameters were then compared with known cometary and NEO (near-Earth object) orbits with the goal to get a broader picture of the associations of known and also suggested parent bodies of the meteoroid streams. From our results, 62 of known associations with the parent bodies were confirmed, and 13 new parent comets were proposed. For 7 meteor showers, new seemingly better solutions among the shower-asteroid associations are suggested. [Display omitted] • Independent identification method of meteor showers. • Meteor shower identification in years 2014–2016 of EDMOND database. • Possible parent bodies candidates for meteoroid streams based on the orbital similarities. • Orbital similarities of possible parent bodies and individual stream meteoroids. [ABSTRACT FROM AUTHOR]

Superbolides, i.e. extremely bright meteors produced by entries of meter-sized bodies into terrestrial atmosphere, are rare events. We present here detailed analysis of a superbolide, which occurred over Romania on January 7, 2015. The trajectory, velocity, and orbit were determined using two all-sky photographs from a station of the European Fireball Network (EN) in Slovakia and five casual video records from Romania, which were carefully calibrated. Bolide light curve was measured by EN radiometers. We found that the entry speed was 27.76±0.19 km s −1 , significantly lower than reported by US Government sensors. The orbit was asteroidal with low inclination and aphelion inside Jupiter's orbit. The atmospheric behavior was, however, not typical for an asteroidal body. The peak brightness of absolute magnitude of −21 was reached at a quite large height of 42.8 km and the brightness then decreased quickly. The bolide almost disappeared at a height of 38.7 km, leaving just a stationary luminous trail visible for several seconds. Only one small fragment continued until the height of 36 km. Brief meteorite searches were unsuccessful. The modeling of the light curve revealed that the body of initial mass of about 4500 kg remained almost intact until the dynamic pressure reached 0.9 MPa but it was then quickly disintegrated into many tiny fragments and dust under 1–3 MPa. A comparison was made with three other superbolides for which we have radiometric light curves: ordinary chondrite fall Košice, carbonaceous chondrite fall Maribo, and cometary Taurid bolide of October 31, 2015. The Romanian superbolide was not similar to any of these and represents probably a new type of material with intrinsic strength of about 1 MPa. [ABSTRACT FROM AUTHOR]

The Polish Fireball Network (PFN) is a project to monitor regularly the sky over Poland in order to detect bright fireballs. In 2016 the PFN consisted of 36 continuously active stations with 57 sensitive analogue video cameras and 7 high resolution digital cameras. In our observations we also use spectroscopic and radio techniques. A PyFN software package for trajectory and orbit determination was developed. The PFN project is an example of successful participation of amateur astronomers who can provide valuable scientific data. The network is coordinated by astronomers from Copernicus Astronomical Centre in Warsaw, Poland. In 2011–2015 the PFN cameras recorded 214,936 meteor events. Using the PFN data and the UFOOrbit software 34,609 trajectories and orbits were calculated. In the following years we are planning intensive modernization of the PFN network including installation of dozens of new digital cameras. [ABSTRACT FROM AUTHOR]

Meteor ablation features in the spectral lines occurring at 394, 436, 520, and 589 nm were observed using a four-camera spectral system between September and December 2015. In conjunction with this multi-camera system the Canadian Automated Meteor Observatory was used to observe the orbital parameters and fragmentation of these meteors. In total, 95 light curves with complete data in the 520 and 589 nm filters were analyzed; some also had partial or complete data in the 394 nm filter, but no usable data was collected with the 436 nm filter. Of the 95 events, 70 exhibited some degree of differential ablation, and in all except 3 of these 70 events the 589 nm filter started or ended sooner compared with the 520 nm filter, indicating early ablation at the 589 nm wavelength. In the majority of cases the meteor showed evidence of fragmentation regardless of the type of ablation (differential or uniform). A surprising result was the lack of correlation found concerning the K B parameter, linked to meteoroid strength, and differential ablation. In addition, 22 shower-associated meteors were observed; Geminids showed mainly slight differential ablation, while Taurids were more likely to ablate uniformly. [ABSTRACT FROM AUTHOR]

The NASA Meteoroid Environment Office (MEO) is often called upon to analyze meteors of public interest observed over the United States. Data from meteor networks are often utilized to accomplish this, as are recordings from the general public. When these methods fail, eyewitness reports are the only resource which can be leveraged. The MEO developed a tool to crudely calculate the trajectories of bright meteors from the eyewitness reports submitted to the American Meteor Society. The tool was tested on eyewitness data for 33 cases and compared to observed data from the NASA All Sky Fireball Network. The tool performed better for cases with more than 75 eyewitness reports than those with fewer than 75, by almost a factor of two across all metrics except for the end height. For these cases, the eyewitness-derived trajectory was about 50 km from the observed trajectory, the radiant was within 15°, and the speed was within 20% of that observed on average. A description of the tool, example case studies, and general trends are described. [ABSTRACT FROM AUTHOR]

An attempt is made to model a meteor observed with the Canadian Automated Meteor Observatory tracking system using a single body model. This meteor showed only very faint wake, implying that fragmentation was not important. Previous attempts to model the meteor with models of fragmenting meteors had overpredicted the amount of wake seen. A single-body, non-homogeneous ablation code was developed, but proved unsuccessful at matching the observed light curve of the meteor, even after a thorough search of parameter space. A model of a meteoroid fragmenting in many small bursts of small fragments was developed in an attempt to match both the light curve and the observed wake, and it succeeded in producing a qualitative fit to the light curve and to the high-resolution wake. [ABSTRACT FROM AUTHOR]

The derivation of meteoroid masses from radar measurements requires conversion of the measured radar cross section (RCS) to meteoroid mass. Typically, this conversion passes first through an estimate of the meteor plasma density derived from the RCS. However, the conversion from RCS to meteor plasma density requires assumptions on the radial electron density distribution. We use simultaneous triple-frequency measurements of the RCS for 63 large meteor head echoes to derive estimates of the meteor plasma size and density using five different possible radial electron density distributions. By fitting these distributions to the observed meteor RCS values and estimating the goodness-of-fit, we determine that the best fit to the data is a 1 / r 2 plasma distribution, i.e. the electron density decays as 1 / r 2 from the center of the meteor plasma. Next, we use the derived plasma distributions to estimate the electron line density q for each meteor using each of the five distributions. We show that depending on the choice of distribution, the line density can vary by a factor of three or more. We thus argue that a best estimate for the radial plasma distribution in a meteor head echo is necessary in order to have any confidence in derived meteoroid masses. [ABSTRACT FROM AUTHOR]

A population of faint meteors with low velocities, and low beginning heights have been described by Borovička et al. (2005) and Campbell-Brown (2015) . They have only iron lines in their spectra. Most of them have unusual light curves that can not be explained by classical single body ablation theory or by fragmentation models. We developed a model which considers iron meteoroids and three different processes of the ablation. The comparison of theoretical and observed meteor heights and light curves leads to the conclusions that (i) vaporization of the liquid from the surface of the meteoroid is too slow a process and it is not able to explain the majority of the observed meteors. (ii) Breakup of the liquid drop would not occur at all or occur at heights which are too low. (iii) The immediate removal of the liquid from the meteoroid's surface and fast release of its kinetic energy is the most probable process leading to the observed meteors. This scenario predicts similar heights, lenghts, and light curves as observed meteors. [ABSTRACT FROM AUTHOR]

The forecasting of meteor showers is currently very good at predicting the timing of meteor outbursts, but still needs further work regarding the level of a given shower. Moreover, uncertainties are rarely provided, leaving the end user (scientist, space agency or the public) with no way to evaluate how much the prediction is trustworthy. A confidence index for the forecasting of meteor showers is presented. It allows one to better understand how a specific forecasting has been performed. In particular, it underlines the role of our current knowledge of the parent body, its past orbit and past activity. The role of close encounters with planets for the time period considered is quantified as well. This confidence index is a first step towards better constrained forecasting of future meteor showers. [ABSTRACT FROM AUTHOR]

This paper examines the effects of the atmospheric density, more specifically, the effects that the changes of isobaric altitude have on the accuracy of a fireball׳s analysis. During winter, especially over high latitude regions like Finland, the true isobaric level may be more than three kilometers below the heights predicted by the US Standard Atmosphere 1976 model. It can differ even more when compared with the heights predicted by the simplified exponential scaled height model. Thus, the true mass of a fireball may differ significantly from those obtained by using either the isobaric altitudes derived from the Standard Atmosphere or the exponential atmospheric model, i.e. without taking into account the corrections for true atmospheric conditions. Likewise, the solutions for the ablation coefficient derived by the generalized models will be less accurate than those that do consider the true atmospheric conditions. This becomes especially crucial for potential meteorite droppers, i.e. low velocity fireballs, with small ablation rates and consequently, high terminal-to-initial mass ratio. We propose an atmospheric height correction method that utilizes real atmospheric data to analysis of the fireball. We demonstrate the proposed method by analyzing the data of three fireballs that were recently recorded by the Finnish Fireball Network and finally, we compare our results against those derived by using the US Standard Atmosphere 1976 model and the exponential atmosphere model. [ABSTRACT FROM AUTHOR]

We present simultaneous optical and radar observations of meteors observed with the Southern Argentine Agile MEteor Radar (SAAMER). Although such observations were performed in the past using High Power and Large Aperture radars, the focus here is on meteors that produced head echoes that can be detected by a significantly less sensitive but more accessible radar system. An observational campaign was conducted in August of 2011, where an optical imager was operated near the radar site in Rio Grande, Tierra del Fuego, Argentina. Six head echo events out of 150 total detections were identified where simultaneous optical meteors could also be clearly seen within the main radar beam. The location of the meteors derived from the radar interferometry agreed very well with the optical location, verifying the accuracy of the radar interferometry technique. The meteor speeds and origin directions calculated from the radar data were accurate—compared with the optics—for the 2 meteors that had radar signal-to-noise ratios above 2.5. The optical meteors that produced the head echoes had horizontal velocities in the range of 29–91 km/s. These comparisons with optical observations improve the accuracy of the radar detection and analysis techniques, such that, when applied over longer periods of time, will improve the statistics of southern hemisphere meteor observations. Mass estimates were derived using both the optical and radar data and the resulting masses agreed well with each other. All were within an order of magnitude and in most cases, the agreement was within a factor of two. [ABSTRACT FROM AUTHOR]

The results of television meteor observations during the Perseid meteor shower activity in 2012–2013 are presented. The observations were carried out in the Moscow region using the television system PatrolCa – the patrol camera with the field of view of 56°×44° and limiting magnitude (for meteors) of +4 m . The distribution of the Index of Meteors Activity of the Perseid meteor shower in 2012–2013 was estimated. The maximum activity occurs on August 12 with the Index of Meteors Activity (IMA) ( λ =140.4°) 192 (±0.03)*10 3 particles to the Earth per 1 h in 2012 and 122 (±0.06)*10 3 particles to the Earth per 1 h in 2013 ( λ =140.2°). In total for 91 meteoroids radiants, geocentric velocities and orbit parameters were calculated. The daily drift of Perseid radiant was determined. The dependence of the beginning and ending heights by absolute magnitude is presented. [ABSTRACT FROM AUTHOR]

More than 7000 two-station meteors observed with two different video systems, both parts of the Canadian Automated Meteor Observatory, have been analysed. The more sensitive (limiting magnitude +6.5) influx system shows a significant population of slow meteors with begin heights under 86 km, while the less sensitive (limiting magnitude +4) tracking system shows many more fast meteors ablating at high altitudes. The low, slow population has asteroidal orbits with low inclinations and moderate eccentricities, and radiants which are not, in general, associated with the sporadic sources. In spite of their low begin heights, which imply that they are strong and refractory, the meteors have early peaked light curves which are not predicted by classical ablation theory for non-fragmenting objects. [ABSTRACT FROM AUTHOR]

All-sky Meteor Orbit System (AMOS) is a semi-autonomous video observatory for detection of transient events on the sky, mostly the meteors. Its hardware and software development and permanent placement on several locations in Slovakia allowed the establishment of Slovak Video Meteor Network (SVMN) monitoring meteor activity above the Central Europe. The data reduction, orbital determination and additional results from AMOS cameras – the SVMN database – as well as from observational expeditions on Canary Islands and in Canada provided dynamical and physical data for better understanding of mutual connections between parent bodies of asteroids and comets and their meteoroid streams. We present preliminary results on exceptional and rare meteor streams such as September ϵ Perseids (SPE) originated from unknown long periodic comet on a retrograde orbit, suspected asteroidal meteor stream of April α Comae Berenicids (ACO) in the orbit of meteorites Příbram and Neuschwanstein and newly observed meteor stream Camelopardalids (CAM) originated from Jupiter family comet 209P/Linear. [ABSTRACT FROM AUTHOR]

On Feb. 15, 2013, a meteoroid with a size of about 19 m plunged into the terrestrial atmosphere at 19 km s −1 and burst at an altitude of about 30 km over the city of Chelyabinsk, Russia. Here we present light curves for the bolide in the red, green, and blue color bands, derived from an analysis of a video that was recorded by a dashboard camera and released on the Internet. Our results demonstrate that the bolide was blue–green in color, which is inconsistent with the Planck spectrum before the meteoroid began to fragment. Fragmentation triggered a flare-up of the bolide and 90% of its radiation energy at optical wavelengths was released within a period of about 2 s after that. During the same period, the brightness ratios among the three bands became consistent with 4000 K blackbody radiation. Based on the peak luminosity, a surface area of several square kilometers would be required for a 4000 K blackbody. It is considered that the radiation source of the bolide was an elongated cloud of vapor and debris produced through severe fragmentation of the meteoroid. [ABSTRACT FROM AUTHOR]

The TUS (Tracking Ultraviolet Set-up) detector is the first fluorescence telescope aimed to measuring Extensive Air Showers (EAS) from space and operated till December 4th, 2017. Despite the main operation mode with a 0.8 μs temporal resolution of the TUS detector was devoted for EAS detection, also it was able to measure different slower luminescent phenomena in the near ultraviolet range. One of the TUS operation modes had 6.6 ​ms temporal resolution and was used to measure micro-meteors and thunderstorm activity. The high sensitivity of the device due to large area of an optical system, makes it a potentially powerful tool for studying dim and fast glow in the Earth's atmosphere. In this work we present the kinematics reconstruction of 13 events recorded by the TUS during 250 ​h of operation, which possess the expected characteristics produced by a meteor (characteristic linear track and light curve). We discuss the possible source of them and their luminosity. This experience of orbital meteor observations is useful for planning similar research in the future more sensitive space missions. • Reconstruction of meteoroid kinematics measured by orbital detector. • Meteor detection with temporal resolution of milliseconds. • Orbital highly sensitive UV telescope is a powerful detector of weak meteor glow. [ABSTRACT FROM AUTHOR]

Abstract: New methods of determining meteor speeds using radar are giving results with an accuracy of better that 1%. It is anticipated that this degree of precision will allow determinations of pre-atmospheric speeds of shower meteors as well as estimates of the density of the meteoroids. The next step is to determine under what conditions these new measurements are reliable. Errors in meteoroid speeds determined using a Fresnel transform procedure applied to radar meteor data are investigated. The procedure determines the reflectivity of a meteor trail as a function of position, by application of the Fresnel transform to the time series of a radar reflection from the trail observed at a single detection station. It has previously been shown that this procedure can be used to determine the speed of the meteoroid, by finding the assumed speed that gives a reflectivity image that best meets physical expectations. It has also been shown that speeds determined by this method agree with those from the well established “pre-to phase” method when applied to reflections with a high signal to noise ratio. However, there is a discrepancy between the two methods for weaker reflections. A method to investigate the discrepancy is described and applied, with the finding that the speed determined by using the Fresnel transform procedure is more accurate for weaker reflections than that given by the “pre-to phase” method. [Copyright &y& Elsevier]

Abstract: Conventional meteoroid theory assumes that the dominant mode of ablation (which we will refer to as thermal ablation) is by evaporation following intense heating during atmospheric flight. Light production results from excitation of ablated meteoroid atoms following collisions with atmospheric constituents. In this paper, we consider the question of whether sputtering may provide an alternative disintegration process of some importance. For meteoroids in the mass range from to and covering a meteor velocity range from 11 to , we numerically modeled both thermal ablation and sputtering ablation during atmospheric flight. We considered three meteoroid models believed to be representative of asteroidal ( mass density), cometary () and porous cometary () meteoroid structures. Atmospheric profiles which considered the molecular compositions at different heights were use in the sputtering calculations. We find that while in many cases (particularly at low velocities and for relatively large meteoroid masses) sputtering contributes only a small amount of mass loss during atmospheric flight, in some cases sputtering is very important. For example, a porous meteoroid at will lose nearly 51% of its mass by sputtering, while a asteroidal meteoroid at will lose nearly 83% of its mass by sputtering. We argue that sputtering may explain the light production observed at very great heights in some Leonid meteors. We discuss methods to observationally test the predictions of these computations. A search for early gradual tails on meteor light curves prior to the commencement of intense thermal ablation possibly represents the most promising approach. The impact of this work will be most dramatic for very small meteoroids such as those observed with large aperture radars. The heights of ablation and decelerations observed using these systems may provide evidence for the importance of sputtering. [Copyright &y& Elsevier]

We present a statistical analysis of meteors observed simultaneously with optical imaging and the Poker Flat Incoherent Scatter Radar (PFISR). The observations analyzed were from 3 nights (3, 4 and October 5, 2010), totaling 20.5 ​h of observation time. Optical observations alone revealed 493 meteors, while the PFISR data contained 9324 meteors over that same time period. There were 224 meteors that were detected by both PFISR and the optical imaging. The focus of this paper is on these 224 meteors that were detected by both methods. For these meteors, the masses were calculated from the optical light curves combined with the total velocities and were found to range between 0.4 and 204 ​mg. Using these meteor observations as a baseline, the minimum meteoroid mass detectable by the PFISR radar was estimated to be around 0.14 ± 0.01 ​mg for a 70 ​km/s meteor. The origination radiants of these 224 meteors were calculated in Heliocentric ecliptic coordinates and they were found to originate from many different areas in the northern hemisphere and not particularly concentrated to any of the sporadic meteor complex sources. • The minimum meteoroid mass detectable by PFISR is estimated to be around 0.14 ​mg. • There is no apparent correlation observed between the raw radar SNR and the optically derived meteoroid mass. • Milligram sized meteors observed at PFISR do not appear to originate from any preferential radiant points. [ABSTRACT FROM AUTHOR]

A sample of 2649 refereed publications in a sub-field of meteor science in 2000–2018 was analysed. The analysed sample included publications relating to meteors and meteoroids, but not to meteorites or interplanetary dust. The number of publications was stable at approximately 160 annually. The mean number of authors per publication increased from about 3.0 (2000–2009) to 4.7–4.9 (2010–2018). The contribution of the single-author publications was higher than in astronomy as the whole, averaging 31% in the first 10 years and 19% in the last 9 years. The number of researchers doubled from 2000 to 2018, reaching 588 in 2018. The mean normalised number of publications per one researcher per year was 0.43, decreasing slightly in the last 8–10 years, but generally being stable. • 2649 refereed publications in meteor science in 2000–2018 were analysed. • The mean annual number of publications is about 160. • The author teams' size increased from about 3.0 (2000–2009) to 4.7–4.9 (2010–2018). • The contribution of the single-author publications was much higher than in astronomy as the whole. • The mean annual number of publications per one researcher was about 0.43. [ABSTRACT FROM AUTHOR]

We collected meteors with iron spectra observed by the newly developed Spectral Digital Autonomous Fireball Observatories (SDAFO). SDAFOs are run within the European Fireball Network and extend the spectral observation of this network. Iron meteoroids can be distinguished using their spectra by the absence of lines of Na, Mg, Cr, Ca, and other usually bright lines of meteoritic origin. Among 220 fireball spectra that were observed by SDAFOs in 2015–2019 and that showed at least three spectral lines, eight were meteors with iron spectra. We added to the collection one additional iron meteor, which was observed with Digital Autonomous Observatories (DAFO: non–spectral cameras), the iron spectrum of which was observed with the spectral cameras of the AMOS Network (Matlovič et al., 2019). We present atmospheric trajectories, light curves, and heliocentric orbits of these iron fireballs. The orbits are asteroidal, or Sun approaching, and show diversity similar to those of mm–sized iron meteoroids. The inclinations vary from nearly zero up to ≈ 70 ∘ . The maximum brightness of all fireballs was between magnitude −6 and −10, corresponding to meteoroid diameters about 1–4 ​cm. Seven fireballs were classified as type IIIA, and two fireballs were classified as type IIIB in the classification of Ceplecha and McCrosky (1976), pointing, at least formally, to fragile bodies comparable in strength to cometary meteoroids. The newly developed model of ablation of small iron meteoroids (Čapek et al., 2019) is based on the spraying of liquid iron from the meteoroid surface. The model was able to derive unambiguous physical properties only for some of the studied cm-sized bodies. Another model, the semi–empirical model of meteoroid fragmentation, was used to fit the light curves. The erosion included in the model was able to fit the light curves by manually adjusting erosion parameters. To describe the sudden drop at the end of the light curve, it was necessary to progressively increase the erosion coefficient and decrease fragment masses along the trajectory. • Eight iron meteoroids were found among 220 fireball spectra. • cm-sized iron meteoroids have diverse asteroidal orbits. • According to end heights, iron fireballs are classified as types IIIA and IIIB. • Two different ablation and fragmentation models were applied to the data. • Decay of large number of droplets can explain quick decrease of light at the end. [ABSTRACT FROM AUTHOR]