Observations of meteors in the Earth’s atmosphere: Reducing data from dedicated double-station wide-angle cameras

Meteoroids entering the Earth’s atmosphere can be observed as meteors, thereby providing useful information on their formation and hence on their parent bodies. We developed a data reduction software package for double station meteor data from the SPOSH camera, which includes event detection, image geometric and radiometric calibration, radiant and speed estimates, trajectory and orbit determination, and meteor light curve recovery. The software package is designed to fully utilise the high photometric quality of SPOSH images. This will facilitate the detection of meteor streams and studies of their trajectories. We have run simulations to assess the performance of the software by estimating the radiants, speeds, and magnitudes of synthetic meteors and comparing them with the a priori values. The estimated uncertainties in radiant location had a zero mean with a median deviation between 0.03∘ and 0.11∘ for the right ascension and 0.02∘ and 0.07∘ for the declination. The estimated uncertainties for the speeds had a median deviation between 0.40 and 0.45 km s−1. The brightness of synthetic meteors was estimated to within +0.01 m. We have applied the software package to 177 real meteors acquired by the SPOSH camera. The median propagated uncertainties in geocentric right ascension and declination were found to be of 0.64∘ and 0.29∘, while the median propagated error in geocentric speed was 1.21 km s−1.

The Fall of Phaethon in Context: A New Synthesis of Mythological, Archaeological and Geological Evidence

The well-known classical myth of Phaethon must be the earliest recorded cautionary tale about teenage driving: taking control of the chariot of his father, the Sun-god, Phaethon set the world ablaze and endangered the cosmic order, until he was felled by Zeus’ thunderbolt and hurled to the earth. It has long been recognised that the tale must reflect some extraordinary astronomical event, recent attempts associating his fall with meteorite impact craters in southern Germany and Estonia. This geographic focus is too narrow. We examine parallels to the myth from ancient Anatolia, Mesopotamia, and the Levant, most previously unrecognised; the tendency of the Greeks to relocalise borrowed myths in the Aegean region or further westwards; and, above all, the unsolved problem aired long ago by Sir James Frazer regarding how remarkably analogous tales are known from as far afield as North America. A proposed impact crater in Iraq may emerge as a suitable candidate for the source of the myth in the Near East. Using developments in the current understanding of comets, meteor, streams and asteroids on earth-crossing orbits, we offer an explanation for both the similarities and differences between the global parallels to the Phaethon story.

Present State and Prospects for the Meteor Research in Ukraine

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

The comet disintegration and meteor streams

Possibility of disintegration of proto-comet nucleus of sungraser comets in three zones of Solar System predicted by one of authors is considered. Testing of parameters of 118 split comets confirms the basic idea. Results of the statistical analysis of comet outbursts gave us additional argument in favor of this assumption. Almost twenty years have passed since, as a result of the search for host phases of isotopically unusual noble gases, the first discovery in 1987 of surviving pre-solar minerals (diamond and silicon carbide) in primitive meteorites. These were followed by others (graphite, refractory oxides, silicon nitride, and finally silicates) in the years since. Pre-solar grains occur in even higher abundance than in meteorites in interplanetary dust particles (IDPs). The result is a kind of ‘new astronomy’ based on the study of pre-solar condensates with all the methods available in modern analytical laboratories.