Search results for: Jiří Borovička

Items from 1 to 20 out of 32 results

article

Chemical and physical properties of Žďár nad Sázavou L chondrite and porosity differentiation using computed tomography

Dominika Kalasová, Tomáš Zikmund, Pavel Spurný, Jakub Haloda, more

Meteoritics & Planetary Science > 55 > 5 > 1073 - 1081

A very bright and long bolide was observed over the eastern part of the Czech Republic during late local evening on December 9, 2014. This bolide was recorded by professional instruments in the Czech part of the European Fireball Network. Three meteorites weighing in total 87 g were found in the predicted area and were named Žďár nad Sázavou. The complete material composition of the meteorite was...

article

The Žďár nad Sázavou meteorite fall: Fireball trajectory, photometry, dynamics, fragmentation, orbit, and meteorite recovery

Pavel Spurný, Jiří Borovička, Lukáš Shrbený

Meteoritics & Planetary Science > 55 > 2 > 376 - 401

We report a comprehensive analysis of the instrumentally observed meteorite fall Žďár nad Sázavou, which occurred in the Czech Republic on December 9, 2014, at 16:16:45–54 UT. The original meteoroid with an estimated initial mass of 150 kg entered the atmosphere with a speed of 21.89 km s⁻¹ and began a luminous trajectory at an altitude of 98.06 km. At the maximum, it reached −15.26 absolute magnitude...

article

The Maribo CM2 meteorite fall—Survival of weak material at high entry speed

Jiří Borovička, Olga Popova, Pavel Spurný

Meteoritics & Planetary Science > 54 > 5 > 1024 - 1041

High entry speed (>25 km s⁻¹) and low density (<2500 kg m⁻³) are the two factors that lower the chance of a meteoroid to drop meteorites. The 26 g carbonaceous (CM2) meteorite Maribo recovered in Denmark in 2009 was delivered by a bright bolide observed by several instruments across northern and central Europe. By reanalyzing the available data, we confirmed the previously reported high entry...

article

Výzvy pro národní politiku obrany planety a těžby asteroidů

Nikola Schmidt, Petr Boháček, Martin Švec, Jiří Borovička, more

Politologická revue (Czech Political Science Review) > 2019 > 2 > 65-99

The following paper examines planetary defense from the perspective of astronomy, which describe scientifically the global nature of the asteroid threat through direct sky observations, technology, which offers concrete solutions of asteroid deflections, international law, which studies within what legal frames planetary defense and asteroid mining is a feasible effort, and finally political science...

article

Editorial

Detlef Koschny, Jiří Borovička, Diego Janches, Iwan P. Willliams

Planetary and Space Science > 2017 > 143 > C > 1-2

article

Ablation of small iron meteoroids–First results

David Čapek, Jiří Borovička

Planetary and Space Science > 2017 > 143 > C > 159-163

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...

article

The January 7, 2015, superbolide over Romania and structural diversity of meter-sized asteroids

Jiří Borovička, Pavel Spurný, Valentin I. Grigore, Ján Svoreň

Planetary and Space Science > 2017 > 143 > C > 147-158

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...

chapter

Elemental Abundances in Leonid and Perseid Meteoroids

Jiří Borovička

Modern Meteor Science An Interdisciplinary View > 245-253

High dispersion photographic spectra of three Leonid and five Perseid meteors are used to derive relative abundances of nine chemical elements in the radiating meteoric vapors and in the meteoroids. Al and Ca were found to be incompletely evaporated in the main spectral component at 5000 K but completely evaporated in the second component at 10,000 K. Si lines are present in both components which...

chapter

Multi-Instrument Observations of Bright Meteors in the Czech Republic

Pavel SpurnÝ, JiŘÍ BoroviČka, Pavel Koten

Modern Meteor Science An Interdisciplinary View > 569-578

We present detailed data on 8 bright meteors recorded simultaneously by different observational techniques. All meteors were recorded by all-sky cameras at the Czech stations of the European Fireball Network and by image intensified TV cameras placed at Ondrejov and Kunzak observatories. As well as direct photographic and LLLTV recordings, most of meteors were recorded also by the spectral TV camera...

chapter

Video and Photographic Spectroscopy of 1998 and 2001 Leonid Persistent Trains from 300 to 930 nm

Shinsuke Abe, Noboru Ebizuka, Hideyuki Murayama, Katsuhito Ohtsuka, more

Modern Meteor Science An Interdisciplinary View > 265-277

Spectra of persistent meteor trains were observed at wavelength between 300 and 930 nm. Two obtained train spectra during the 1998 and 2001 Leonid meteor showers are reported here. During the 1998 Leonids, one train was detected by a photographic camera with a spectrograph covering 370–640 nm region. On the other hand, during the 2001 Leonids, video observations were carried out using image intensified...

article

On the age and formation mechanism of the core of the Quadrantid meteoroid stream

Abedin Abedin, Pavel Spurný, Paul Wiegert, Petr Pokorný, more

Icarus > 2015 > 261 > Complete > 100-117

The Quadrantid meteor shower is among the strongest annual meteor showers, and has drawn the attention of scientists for several decades. The stream is unusual, among others, for several reasons: its very short duration around maximum activity (≈12–14h) as detected by visual, photographic and radar observations, its recent onset (around 1835 AD Quetelet, L.A.J. [1839]. Catalogue des principles apparitions...

article

The Košice meteorite fall: Recovery and strewn field

Juraj Tóth, Ján Svoreň, Jiří Borovička, Pavel Spurný, more

Meteoritics & Planetary Science > 50 > 5 > 853 - 863

We provide the circumstances and details of the fireball observation, search expeditions, recovery, strewn field, and physical characteristics of the Košice meteorite that fell in Slovakia on February 28, 2010. The meteorite was only the 15th case of an observed bolide with a recovered mass and subsequent orbit determination. Despite multiple eyewitness reports of the bolide, only three videos from...

article

The 2011 Draconids: The First European Airborne Meteor Observation Campaign

Jeremie Vaubaillon, Pavel Koten, Anastasios Margonis, Juraj Toth, more

Earth, Moon, and Planets > 2015 > 114 > 3-4 > 137-157

On 8 October 2011, the Draconid meteor shower (IAU $$\#8$$ # 8 , DRA) was predicted to cause two brief outbursts of meteors, visible from locations in Europe. For the first time, a European airborne meteor observation campaign was organized, supported by ground-based observations. Two aircraft were deployed from Kiruna, Sweden, carrying six scientists, 19 cameras and eight crew members. The...

article

Density, porosity and magnetic susceptibility of the Košice meteorite shower and homogeneity of its parent meteoroid

Tomáš Kohout, Karol Havrila, Juraj Tóth, Marek Husárik, more

Planetary and Space Science > 2014 > 93-94 > Complete > 96-100

Bulk and grain densities, porosities, and magnetic susceptibilities of 67 individuals of Košice H chondrite fall were measured. The mean bulk and grain densities were determined to be 3.43g/cm ³ with standard deviation (s.d.) of 0.11g/cm ³ and 3.79g/cm ³ with s.d. 0.07g/cm ³ , respectively. Porosity is in the range from 4.2% to 16.1%. The logarithm of the apparent magnetic...

article

The localization of fireball trajectories with the help of seismic networks

Pavel Kalenda, Jiří Borovička, Pavel Spurný

Studia Geophysica et Geodaetica > 2014 > 58 > 1 > 84-99

The seismic network can be used for the localization of the fireball trajectory in the atmosphere. The types of sonic or blasting waves, created during the meteorid’s penetration of the atmosphere, are discussed. The practical use of the localization based on cylindrical or spherical waves is shown on the examples of fireballs Morávka (2000), Břeclav (2007), Jesenice (2009) and Košice (2010).

article

Spectral, Photometric, and Dynamic Analysis of Eight Draconid Meteors

Jiří Borovička, Pavel Koten, Lukáš Shrbený, Rostislav Štork, more

Earth, Moon, and Planets > 2014 > 113 > 1-4 > 15-31

We analyzed spectra, trajectories, orbits, light curves, and decelerations of eight Draconid meteors observed from Northern Italy on October 8, 2011. Meteor morphologies of two of the meteors are also presented, one of them obtained with a high resolution camera. Meteor radiants agree with theoretical predictions, with a hint that some meteors may belong to the pre-1900 meteoroid trails. The spectra...

article

The Košice meteorite fall: Atmospheric trajectory, fragmentation, and orbit

Jiří Borovička, Juraj Tóth, Antal Igaz, Pavel Spurný, more

Meteoritics & Planetary Science > 48 > 10 > 1757 - 1779

The Košice meteorite fall occurred in eastern Slovakia on February 28, 2010, 22:25 UT. The very bright bolide was imaged by three security video cameras from Hungary. Detailed bolide light curves were obtained through clouds by radiometers on seven cameras of the European Fireball Network. Records of sonic waves were found on six seismic and four infrasonic stations. An atmospheric dust cloud was...

article

The Bunburra Rockhole meteorite fall in SW Australia: fireball trajectory, luminosity, dynamics, orbit, and impact position from photographic and photoelectric records

Pavel SPURNÝ, Philip A. BLAND, Lukáš SHRBENÝ, Jiří BOROVIČKA, more

Meteoritics & Planetary Science > 47 > 2 > 163 - 185

Abstract– We report an analysis of the first instrumentally observed meteorite fall in Australia, which was recorded photographically and photoelectrically by two eastern stations of the Desert Fireball Network (DFN) on July 20, 2007. The meteoroid with an initial mass of 22 kg entered the atmosphere with a low speed of 13.36 km s⁻¹ and began a luminous trajectory at an altitude of 62.83 km. In maximum,...

article

Very low strengths of interplanetary meteoroids and small asteroids

Olga POPOVA, Jiří BOROVIČKA, William K. HARTMANN, Pavel SPURNÝ, more

Meteoritics & Planetary Science > 46 > 10 > 1525 - 1550

Abstract– We have assembled data on 13 cases of meteorite falls with accurate tracking data on atmospheric passage. In all cases, we estimate the bulk strength of the object corresponding to its earliest observed or inferred fragmentation in the high atmosphere, and can compare these values with measured strengths of meteorites in the taxonomic class for that fall. In all 13 cases, the strength corresponding...

article

Analysis of instrumental observations of the Jesenice meteorite fall on April 9, 2009

Pavel SPURNÝ, Jiří BOROVIČKA, Javor KAC, Pavel KALENDA, more

Meteoritics & Planetary Science > 45 > 8 > 1392 - 1407

Abstract– We report an analysis of instrumental observations of a very bright fireball which terminated with a meteorite fall near the town of Jesenice in Slovenia on April 9, 2009, at 0h59m46s UT. The fireball designated EN090409 was recorded photographically and photoelectrically by two southern stations of the Czech part of the European Fireball Network (EN). Simultaneously, a part of the luminous...

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Search results for: Jiří Borovička

Chemical and physical properties of Žďár nad Sázavou L chondrite and porosity differentiation using computed tomography

The Žďár nad Sázavou meteorite fall: Fireball trajectory, photometry, dynamics, fragmentation, orbit, and meteorite recovery

The Maribo CM2 meteorite fall—Survival of weak material at high entry speed

Výzvy pro národní politiku obrany planety a těžby asteroidů

Editorial

Ablation of small iron meteoroids–First results

The January 7, 2015, superbolide over Romania and structural diversity of meter-sized asteroids

Elemental Abundances in Leonid and Perseid Meteoroids

Multi-Instrument Observations of Bright Meteors in the Czech Republic

Video and Photographic Spectroscopy of 1998 and 2001 Leonid Persistent Trains from 300 to 930 nm

On the age and formation mechanism of the core of the Quadrantid meteoroid stream

The Košice meteorite fall: Recovery and strewn field

The 2011 Draconids: The First European Airborne Meteor Observation Campaign

Density, porosity and magnetic susceptibility of the Košice meteorite shower and homogeneity of its parent meteoroid

The localization of fireball trajectories with the help of seismic networks

Spectral, Photometric, and Dynamic Analysis of Eight Draconid Meteors

The Košice meteorite fall: Atmospheric trajectory, fragmentation, and orbit

The Bunburra Rockhole meteorite fall in SW Australia: fireball trajectory, luminosity, dynamics, orbit, and impact position from photographic and photoelectric records

Very low strengths of interplanetary meteoroids and small asteroids

Analysis of instrumental observations of the Jesenice meteorite fall on April 9, 2009

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