Meteor Showers Research Articles

Optical fluxes and meteor properties of the camelopardalid meteor shower

Observations of the Camelopardalid meteor shower in May 2014 were obtained with six different sets of cameras, with limiting meteor magnitudes varying from −2M to +7M. Shower fluxes were calculated for each of the systems, from which the mass index of the shower was found to be 2.17 ± 0.04. Faint meteors in the shower were found to be stronger than average, ablating at lower altitudes than meteors at the same speed recorded with the same system, while the brightest meteors had higher ablation heights and were therefore weaker than typical meteors. These findings can be explained if large Camelopardalids are weak agglomerations of more refractory grains, which are easily disrupted in space and keep the shower supplied with small material and depleted in large material.

Three-body resonance in meteoroid streams

Mean-motion resonances play an important role in the evolution of various meteoroid streams. Previous works have studied the effects of two-body resonances in different comets and streams. These already established two-body resonances were mainly induced either by Jovian or Saturnian effects but not both at the same time. Some of these resonances have led to spectacular meteor outbursts and storms in the past. In this work, we find a new resonance mechanism involving three bodies -- i.e. meteoroid particle, Jupiter and Saturn, in the Perseid meteoroid stream. Long-term three-body resonances are not very common in real small bodies in our solar system although they can mathematically exist at many resonant sweet spots in an abstract sense in any dynamical system. This particular resonance combination in the Perseid stream is such that it is close to the ratio of 1:4:10 if the orbital periods of Perseid particle, Saturn and Jupiter are considered respectively. These resonant Perseid meteoroids stay resonant for typically about 2 kyr. Highly compact dust trails due to this unique resonance phenomenon are present in our simulations. Some past and future years are presented where three-body resonant meteoroids of different sizes (or subject to different radiation pressures) are computed to come near the Earth. This is the first theoretical example of an active and stable three-body resonance mechanism in the realm of meteoroid streams.

An Earth-grazing fireball from the Daytime ζ-Perseid shower observed over Spain on 2012 June 10

On 10 June 2012, an Earth-grazer meteor which lasted over 17 s with an absolute magnitude of -4.0 $\pm$ 0.5 was observed over Spain. This work focuses on the analysis of this rare event which is, to our knowledge, the faintest Earth-grazing meteor reported in the scientific literature, but also the first one belonging to a meteor shower. Thus, the orbital parameters show that the parent meteoroid belonged to the Daytime $\zeta$-Perseid meteoroid stream. According to our calculations, the meteor was produced by a meteoroid with an initial mass ranging between 115 and 1.5 kg. During its encounter with Earth, the particle travelled about 510 km in the atmosphere. Around 260 g were destroyed in the atmosphere during the luminous phase of the event as a consequence of the ablation process. The modified orbit of the remaining material, which left our planet with a fusion crust, is also calculated.

A Survey of Meteoric Activity over Spain during the Eighth–Fifteenth Centuries

The lack of astronomical observations from medieval and early modern Spanish sources is a constant in the records of solar eclipses, meteors, and other celestial phenomena. This may be partially explained by the absence of a documentary corpus similar to the Monumenta Germaniae Historica, for example, that scholars may use for conducting a systematic search of such records; the problems increase by the presence of four different vernacular languages in the peninsula: Castilian, Catalan, Basque, and Galician, together with some other minority languages, to which Latin and Arabic must be added for historical research purposes. Currently, scientific literature records few medieval Spanish astronomical accounts, and most of them are contained in wider Arab surveys or they come from the best-known annals and chronicles. Our article intends to fill this gap partially in the issue of meteoritic activity. We present a survey of meteors, bolides, and meteor storms observed in Spain in the eighth–fourteenth centuries. Most of them have not been previously published and come from local or minor sources, but for the sake of completeness, we have included some records already mentioned by other authors.

Observations of the Quadrantid meteor shower from 2008 to 2012: Orbits and emission spectra

The activity of the Quadrantids in January during several years (2008, 2010, 2011 and 2012) has been investigated in the framework of the SPanish Meteor Network (SPMN). For this purpose, an array of high-sensitivity CCD video devices and CCD all-sky cameras have been used to obtain multi-station observations of these meteors. These allowed to obtain precise radiant and orbital information about this meteoroid stream. This paper presents a large set of orbital data (namely, 85 orbits) of Quadrantid meteoroids. Most meteors produced by these particles were recorded during the activity peak of this shower. Besides, we discuss four Quadrantid emission spectra. The tensile strength of Quadrantid meteoroids has been also obtained.

A study to improve the past orbit of comet C/1917 F1 (Mellish) on the basis of its observed meteor showers

Context. Periodic comets are known to be the parent bodies of meteoroid streams. The stream of a given comet can split into several filaments. These can be observed in the Earth’s atmosphere as more than just a single meteor shower. One such comet is C/1917 F1 (Mellish), which associates at least two, possibly four, meteor showers that have been recorded in the meteor databases. In a recent study, the dynamical evolution of the C/1917 F1’s theoretical stream was followed by only considering the gravitational perturbations. The properties of individual filaments of this stream, corresponding to the appropriate meteor showers, were not predicted perfectly. Aims. To reach better agreement between theory and observation, we repeatedly model the theoretical stream of C/1917 F1. In the modeling, we also include the Poynting-Robertson drag acting on meteoroids and assume an action of the non-gravitational effects on the parent comet dynamics. If success was achieved, the modeling could become a tool that would enable us to recover the past orbital history of the parent comet. Methods. Considering the nominal orbit, as well as several cloned orbits, of the comet C/1917 F1, we modeled its theoretical streams. The modeling was performed for several past perihelion passages. Each modeled stream consists of 10 000 test particles that are influenced by the Poynting-Robertson drag of various strengths. Results. We achieve a partial improvement in the prediction of the properties of all four meteor showers. The Poynting-Robertson drag helps to improve the match between the theory and observation of three of the four showers. However, when considering the nominal orbit of the parent comet, a perfect match seems to be impossible. A close match in the case of the most problematic shower is achieved using a cloned orbit, but this is not applicable to reality because the simultaneous predictions of the properties of the other three showers fail.

Dust impact signals on the wind spacecraft

AbstractWe analyze waveforms recorded by the Time Domain Sampler of the WAVES experiment on Wind which are similar to impulsive waveforms observed by the S/WAVES experiment on STEREO. These have been interpreted as dust impacts by Meyer‐Vernet et al. and M. L. Kaiser and K. Goetz and extensively analyzed by Zaslavsky et al. The mechanism for coupling the emission to the antennas to produce an electrical signal is still not well understood, however. One suggested mechanism for coupling of the impact to the antenna is that the spacecraft body changes potential with respect to the surrounding plasma but the antennas do not (the body mechanism). Another class of mechanisms, with several forms, is that the charge of the emitted cloud interacts with the antennas. The Wind data show that both are operating. The time domain shapes of the dust pulses are highly variable but we have little understanding of what provides these shapes. One feature of the STEREO data has been interpreted as impacts from high velocity nanoparticles entrained by the solar wind. We have not found evidence for fast nanodust in the Wind data. An appreciable fraction of the impacts observed on Wind is consistent with interstellar dust. The impact rates do not follow a Poisson distribution, expected for random independent events, and this is interpreted as bunching. We have not succeeded in relating this bunching to known meteor showers, and they do not repeat from 1 year to the next. The data suggest bunching by fields in the heliosphere.

Mesospheric temperature estimation from meteor decay times during Geminids meteor shower

AbstractMeteor radar observations at the Sodankylä Geophysical Observatory (67° 22′N, 26° 38′E, Finland) indicate that the mesospheric temperature derived from meteor decay times is systematically underestimated by 20–50 K during the Geminids meteor shower which has peak on 13 December. A very good coincidence of the minimum of routinely calculated temperature and maximum of meteor flux (the number of meteors detected per day) was observed regularly on that day in December 2008–2014. These observations are for a specific height‐lifetime distribution of the Geminids meteor trails and indicate a larger percentage of overdense trails compared to that for sporadic meteors. A consequence of this is that the routine estimates of mesospheric temperature during the Geminids are in fact underestimates. The observations do, however, indicate unusual properties (e.g., mass, speed, or chemical composition) of the Geminids meteoroids. Similar properties were found also for Quadrantids in January 2009–2015, which like the Geminids has as a parent body an asteroid, but not for other meteor showers.

The Mexican Meteor Network: A Preliminary Proposal

The study of asteroidal and cometary material entering into Earth’s atmosphere has scientific and social importance. The observation and study of the impact of meteoroids with our planet is a way of studying geophysics and planetary geology without spaceships. This article describes the progress of the installation of the Mexican Meteor Network (Citlalin Tlamina). At medium and long term, the aim of this network is to cover the entire national territory with stations that allow us to record the entry of meteoroids into Earth’s atmosphere. This seeks to: a) study the meteoroid-atmosphere interaction, b) determine impactor’s physical properties; c) analyze flows and Radiant deviations of known meteor showers, d) find or ratify new meteor showers; e) recover and study meteorites, f) study the interaction of the shock wave with the ground by analyzing seismograms; g) report people in real time (or near) the occurrence of fireballs and fragmentation of meteoroids in the atmosphere, avoiding the fear of this phenomenon and provide support for Civil Protection, h) find areas of opportunity that can use the images captured by the cameras (weather, bird migration, etc.). In this paper, it is shown the prototype of the base to house the cameras whose purpose is to protect them from the environment, prevent condensation within the container and keep the cameras below 25 °C.

Gifts of the South, and: Birmingham

Gifts of the South, and: Birmingham Christopher Petrucelli (bio) GIFTS OF THE SOUTH An Eclipse The moon, redlike fat drippingfrom the porterhouseside of the T-Bone,an American Godin its own rites.Beef moon, nurturingour ebb and flowwith hands that kneadus to tendernessand umami. Then,a cleanse, clean as ginstraight up tasting likeclear night sky. A Supercell I thought it too muchto cull storms, but flailedhail that punctured metalrooftops. I spun windwith my wantinginto the fabric of air.In that brief hourof power outage, a momentto rest under blue stars. [End Page 78] A Meteor Shower Dust flung by the BigDipper, Ursa Major,radiance at Camelopardalis.The storm gifted twometeors the size of fireflies—fat, slow and glowingover Tennessee, whilethe rest of the humblescatter lit black grassin rolling foothills of Appalachia. A Pastime Moonshine—a mashof corn and taste of dirt.My home in glass diorama,soon to be an empty vessel.I tilt back my headimpossibly far until southernroots set fire to mythroat and make stillthe sounds of chords. [End Page 79] BIRMINGHAM Vulcan rises from the black top.Both hands forming the other,fingers work loose pig iron into arms. The Buick, rusted and scraped, rattles down I-65 where the rolling hills level out like a gasping bellow. The hands squeeze, workwhite-hot metal and mold legsto torso with scratches and scores. On 5th Avenue I had my first taste of deep south, the air so wet it became waterfire—throat and skin scorched. [End Page 80] Hammer to the ground, spear to sky,knees bleeding with slag, Vulcanstands above Red Mountain. That night I saw Charon in the hot mist paddling over the bar, his boat made more clear with each drag of a cigarette, each blow of smoke. [End Page 81] Christopher Petrucelli Christopher Petrucelli is a graduate student at the University of Alaska, Fairbanks and an associate poetry editor at Stirring a Literary collection. His poetry has appeared in Connotation Press, Rappahannock Review, Still: The Journal, and elsewhere. His chapbook, Action at a Distance, is available from UIndy’s Etchings Press. Copyright © 2016 Berea College

Performance ofD-criteria in isolating meteor showers from the sporadic background in an optical data set

Separating meteor showers from the sporadic meteor background is critical for the study of both showers and the sporadic complex. The linkage of meteors to meteor showers, to parent bodies, and to other meteors is done using measures of orbital similarity. These measures often take the form of so-called D-parameters and are generally paired with some cutoff value within which two orbits are considered related. The appropriate cutoff value can depend on the size of the data-set (Southworth & Hawkins 1963), the sporadic contribution within the observed size range (Jopek 1995), or the inclination of the shower (Galligan 2001). If the goal is to minimize sporadic contamination of the extracted shower, the cutoff value should also reflect the strength of the shower compared to the local sporadic background. In this paper, we present a method for determining, on a per-shower basis, the orbital similarity cutoff value that corresponds to a chosen acceptable false-positive rate. This method also assists us in distinguishing which showers are significant within a set of data. We apply these methods to optical meteor observations from the NASA All-Sky and Southern Ontario Meteor Networks.

BANGS AND METEORS FROM THE QUIET COMET 15P/FINLAY

Jupiter-family comet 15P/Finlay has been reportedly quiet in activity for over a century but has harbored two outbursts during its 2014/2015 perihelion passage. Here we present an analysis of these two outbursts using a set of cometary observations. The outbursts took place between 2014 December 15.4–16.0 UT and 2015 January 15.5–16.0 UT as constrained by ground-based and spacecraft observations. We find a characteristic ejection speed of V0 = 300–650 m s−1 for the ejecta of the first outburst and V0 = 550–750 m s−1 for that of the second outburst using a Monte Carlo dust model. The mass of the ejecta is calculated to be Md = (2–3) × 105 kg for the first outburst and Md = (4–5) × 105 kg for the second outburst, which corresponds to less than 10−7 of the nucleus mass. The specific energy of the two outbursts is found to be (0.3–2) × 105 J kg−1. We also revisit the long-standing puzzle of the nondetection of the hypothetical Finlayid meteor shower by performing a cued search using the 13 yr data from the Canadian Meteor Orbit Radar, which does not reveal any positives. Earth will pass the 2014/2015 outburst ejecta between 2021 October 6 at 22 hr UT and October 7 at 1 hr UT, with a chance for some significant meteor activity in the radio range, which may provide further clues to the Finlayid puzzle. A southerly radiant in the constellation of Ara will favor the observers in the southern tip of Africa.

CAMS newly detected meteor showers and the sporadic background

The Cameras for Allsky Meteor Surveillance (CAMS) video-based meteoroid orbit survey adds 60 newly identified showers to the IAU Working List of Meteor Showers (numbers 427, 445–446, 506–507, and part of 643–750). 28 of these are also detected in the independent SonotaCo survey. In total, 230 meteor showers and shower components are identified in CAMS data, 177 of which are detected in at least two independent surveys. From the power-law size frequency distribution of detected showers, we extrapolate that 36% of all CAMS-observed meteors originated from ∼700 showers above the N=1 per 110,000 shower limit. 71% of mass falling to Earth from streams arrives on Jupiter-family type orbits. The transient Geminids account for another 15%. All meteoroids not assigned to streams form a sporadic background with highest detected numbers from the apex source, but with 98% of mass falling in from the antihelion source. Even at large ∼7-mm sizes, a Poynting–Robertson drag evolved population is detected, which implies that the Grün et al. collisional lifetimes at these sizes are underestimated by about a factor of 10. While these large grains survive collisions, many fade on a 104-y timescale, possibly because they disintegrate into smaller particles by processes other than collisions, leaving a more resilient population to evolve.The meteors assigned to the various showers are identified in the CAMS Meteoroid Orbit Database 2.0 submitted to the IAU Meteor Data Center, and can be accessed also at http://cams.seti.org.

CAMS verification of single-linked high-threshold D-criterion detected meteor showers

From preliminary 2010–2011 results of the Cameras for Allsky Meteor Surveillance (CAMS) meteoroid orbit survey, which were combined with published 2007–2009 SonotaCo video meteor network data, 55 new meteor showers (##448–502) were identified and added to the IAU Working List on Meteor Showers in 2012. These showers were identified based on an automated single-linked DSH-criterion analysis of a combined 105,000 orbits with high-threshold (a low DSH<0.05), but low acceptable sample size (⩾6 members). Three more years of CAMS and four more years of SonotaCo observations have now increased the meteoroid orbit database four fold. The earlier detections are verified by searching for number density enhancements in drift-corrected radiant and orbital element maps. Twenty showers are detected in both surveys and are now certain to exist. Median orbital elements are presented. Not detected in this manner were 19% of the fast Vg>40km/s showers, 54% of the Vg=18–40km/s showers, and 90% of the slow Vg<18km/s showers.

THE NEED OF DISTANCE LEARNING FOR ASTRONOMY DEVELOPMENT IN INDONESIA

Astronomy is a popular topic for the public in term of astronomical phenomenon such as occultations, solar and lunar eclipses or meteor showers. In term of education, astronomy also is popular as one of the world Science Olympiads. Social media, as the new trend in communicating and connecting people, plays a significant role in increasing the size of the astronomy community. Beyond IYA 2009, more and more astronomy activities have been done in many places in Indonesia. New astronomy communities have been formed in several cities and public engagement is also high in social media especially on Facebook and Twitter. In this paper, we will discuss the lesson learned from astronomy outreach achievements in Indonesia and the need for citizen science projects as a distance learning tool for the public as part of astronomy development in Indonesia. We argue and propose that this project will be also important up to a regional scope.

THE 2014 KCG METEOR OUTBURST: CLUES TO A PARENT BODY

The Kappa Cygnid (KCG) meteor shower exhibited unusually high activity in 2014, producing ten times the typical number of meteors. The shower was detected in both radar and optical systems and meteoroids associated with the outburst spanned at least five decades in mass. In total, the Canadian Meteor Orbit Radar, European Network, and NASA All Sky and Southern Ontario Meteor Network produced thousands of KCG meteor trajectories. Using these data, we have undertaken a new and improved characterization of the dynamics of this little-studied, variable meteor shower. The Cygnids have a di use radiant and a significant spread in orbital characteristics, with multiple resonances appearing to play a role in the shower dynamics. We conducted a new search for parent bodies and found that several known asteroids are orbitally similar to the KCGs. N-body simulations show that the two best parent body candidates readily transfer meteoroids to the Earth in recent centuries, but neither produces an exact match to the KCG radiant, velocity, and solar longitude. We nevertheless identify asteroid 2001 MG1 as a promising parent body candidate.

Astronomers find 86 previously unknown meteor showers

Astronomers find 86 previously unknown meteor showers

The established meteor showers as observed by CAMS

Orbital elements are presented for 70 of the 95 meteor showers considered “established” by the International Astronomical Union. From 2010 October 21 until 2013 March 31, the low-light-video based Cameras for Allsky Meteor Surveillance project (CAMS) measured a total of 110,367 meteoroid trajectories and pre-atmospheric orbits from mostly −2 to +4 magnitude meteors with a precision of <2° (median 0.4°) in apparent radiant direction and <10% (median 0.9%) in speed. This paper discusses how the already established showers manifest in this data. Newly resolved components in the radiant distribution shed light on the dynamics and physical lifetime of parent bodies and their meteoroids. Many multi-component showers have associated parent bodies with nodal lines not much rotated from that of their meteoroids (Encke Complex, Machholz Complex, Phaethon Complex, and now also the 169P/NEAT Complex). These may result from a parent body disruption cascade, with the disruption-generated meteoroids fading on the short timescale of a few hundred to a few thousand years. In particular, the Northern and Southern Taurids of the Encke Complex are decomposed here into 19 individual streams. Seven of these streams can be paired with mostly sub-km sized potential parent body asteroids that move in 2P/Encke-like orbits that span the narrow semi-major axis range of 2.20–2.35AU. The meteoroids in these Taurid streams do not survive long enough for the nodal line to fully rotate relative to that of their parent body.

Falling Stars as Seen From the Balloon

T ravels in the Air is a 19th-century narrative of balloon ascents by meteorologist James Glaisher (1809-1903), astronomer Camille Flammarion, science journalist Wilfrid de Fonvielle, and chemist Gaston Tissandier. Falling Stars as Seen From the Balloon, by Albert Tissandier (18391906), is a chromolithograph from Travels in the Air that illustrates de Fonvielle’s balloon flight of November 14-15, 1867, to view the Leonid meteor shower. In this romantically shaded image, the trajectories of several meteors are superimposed in the night sky. In 1867 an observer would have had to look directly into the moonlight to see the Leonids, but hundreds of meteors were visible despite the glare. De Fonvielle was born in Paris, France, in 1826. He was a student of mathematics in 1848 when the citizens of Paris rebelled against the monarchy of King Louis Philippe. In the subsequent suppression, De Fonvielle, who was a staunch supporter of the insurrection, was arrested and expelled from the country. Eventually he was allowed to return to France, where he became a writer and editor for the scientific publications La Nature, L'Aerophile, and Lumiere Electrique. During the 1850s De Fonvielle made scientific observations in gasfilled balloons. His flight of November 14-15, 1867, was in a small balloon called L'hirondelle. There was just room in the basket for provisions, warm clothing, scientific instruments, and three men: de Fonvielle, the balloon’s owner, and an American aeronaut who wore a parachute and offered to jump out (in poor light, over unknown terrain) if there was a need to lighten the craft. After filling the balloon with hydrogen gas, the aeronauts ascended in the dark, admiring the lights of Paris as

TV observations of the Perseid meteor shower in 2012–2013

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 +4m. 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)*103 particles to the Earth per 1h in 2012 and 122 (±0.06)*103 particles to the Earth per 1h 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.