|
|
Properties of faint meteors studied by video observations
Vojáček, Vlastimil ; Borovička, Jiří (advisor) ; Campbell-Brown, Margaret (referee) ; Tóth, Juraj (referee)
Parallel double-station video observations paired with spectroscopic video observations are a good way to study millimetre-sized meteoroids. Almost two decades of video observations of meteors at the Ondřejov observatory give us broad database to study large quantities of meteoroids and their properties. In this work we combined spectral video observations and results of the modelling of the fragmentation of meteoroids. Along with complex infor- mation about meteoroid's trajectories and orbits, this can give us better understanding about origin, internal structure etc. of these millimetre-sized interplanetary bodies. Meteoroids that contained small grains tend to release the sodium early. Since there is a smaller amount of sodium for Na depleted meteoroids, the sodium was released earlier than it was released for meteoroids with same grain sizes and without the sodium depletion. Overall, meteoroids with sodium depletion showed different composition: they were composed of stronger material without very small grains and they did not showed very bright wakes. Two iron meteoroids on Halley type orbits were observed. They are probably remnants of complicated early years of our solar system. The dis- tribution of grain sizes of Jupiter-family members was in a good agreements with results from the COSIMA...
|
|
|
Dynamics of small bodies in the Solar System: from dust particles to asteroid
Pokorný, Petr
In this thesis, we study two different topics: collisional probability between two bodies and dynamics of the sporadic meteoroids in the Solar System. Determination of the collision probabilities in the Solar System is one of the important problems in mod- ern celestial mechanics. Here, we generalize classical theories of the collisions between two bodies by Öpik, Wetherill or Greenberg by including the Kozai-Lidov oscillations, a mechanism that significantly change orbital eccentricity and inclination in the Solar System. Sporadic meteors have been studied for many decades providing a wealthy re- source of data. Here, we build dynamical steady-state models for all known populations observed in the sporadic meteoroid complex based on the latest and most precise data provided by Canadian Meteor Orbit Radar (CMOR). Our models using the latest theo- ries for cometary populations in the Solar System accurately describe observed sporadic background population. Our results are in agreement with observations provided by space probes IRAS and LDEF.
|
|
|
Analysis of solid samples using calibration free laser induced breakdown spectroscopy - application in metallurgy of meteorites
Petera, Lukáš ; Ferus, Martin (advisor) ; Krůs, Miroslav (referee)
The aim of this thesis was the development and application of the calibration-free method of the laser induced breakdown spectroscopy (LIBS). The CF-LIBS method is used to quickly analyze of sample of any size and shapes without any required surface treatment, to determinate their elemental composition. In addition, the CF algorithm is also usefull for study of atomic plasma and hot gas emision spectra to determinate their elemental composition. From this point of view, very interesting is ablation analysis of complicated matrices such as meteorites and possible comparsion with spectral analysis of meteors. In the frame of the presented bachelor thesis, was measured the ablation spectra of meteorite samples Porangaba (L4), Chellyabinsk (LL5), Northwest Africa 869 (L3-6) and Dhofar 1994 (CM2). Based on the measured spectra of these meteorites, was created an atlas of the emision lines and assigned parameters of the spectroscopic transitions of the elements, typically occuring in a meteorites. Thisatlas will also serve as the source database for automatic pragram Ablator (automatically evalueting of ablation emission spcectra) and MeteorMaster (automatic program for the interpretation of meteors spectra). The database will be used for CF-LIBS analysis of the Porangaba meteorite. The database is...
|
|
|
Properties of faint meteors studied by video observations
Vojáček, Vlastimil ; Borovička, Jiří (advisor) ; Campbell-Brown, Margaret (referee) ; Tóth, Juraj (referee)
Parallel double-station video observations paired with spectroscopic video observations are a good way to study millimetre-sized meteoroids. Almost two decades of video observations of meteors at the Ondřejov observatory give us broad database to study large quantities of meteoroids and their properties. In this work we combined spectral video observations and results of the modelling of the fragmentation of meteoroids. Along with complex infor- mation about meteoroid's trajectories and orbits, this can give us better understanding about origin, internal structure etc. of these millimetre-sized interplanetary bodies. Meteoroids that contained small grains tend to release the sodium early. Since there is a smaller amount of sodium for Na depleted meteoroids, the sodium was released earlier than it was released for meteoroids with same grain sizes and without the sodium depletion. Overall, meteoroids with sodium depletion showed different composition: they were composed of stronger material without very small grains and they did not showed very bright wakes. Two iron meteoroids on Halley type orbits were observed. They are probably remnants of complicated early years of our solar system. The dis- tribution of grain sizes of Jupiter-family members was in a good agreements with results from the COSIMA...
|
|
|
Dynamics of small bodies in the Solar System: from dust particles to asteroid
Pokorný, Petr ; Vokrouhlický, David (advisor) ; Borovička, Jiří (referee) ; Wiegert, Paul (referee)
In this thesis, we study two different topics: collisional probability between two bodies and dynamics of the sporadic meteoroids in the Solar System. Determination of the collision probabilities in the Solar System is one of the important problems in mod- ern celestial mechanics. Here, we generalize classical theories of the collisions between two bodies by Öpik, Wetherill or Greenberg by including the Kozai-Lidov oscillations, a mechanism that significantly change orbital eccentricity and inclination in the Solar System. Sporadic meteors have been studied for many decades providing a wealthy re- source of data. Here, we build dynamical steady-state models for all known populations observed in the sporadic meteoroid complex based on the latest and most precise data provided by Canadian Meteor Orbit Radar (CMOR). Our models using the latest theo- ries for cometary populations in the Solar System accurately describe observed sporadic background population. Our results are in agreement with observations provided by space probes IRAS and LDEF.
|
|
|
Dynamics of small bodies in the Solar System: from dust particles to asteroid
Pokorný, Petr
In this thesis, we study two different topics: collisional probability between two bodies and dynamics of the sporadic meteoroids in the Solar System. Determination of the collision probabilities in the Solar System is one of the important problems in mod- ern celestial mechanics. Here, we generalize classical theories of the collisions between two bodies by Öpik, Wetherill or Greenberg by including the Kozai-Lidov oscillations, a mechanism that significantly change orbital eccentricity and inclination in the Solar System. Sporadic meteors have been studied for many decades providing a wealthy re- source of data. Here, we build dynamical steady-state models for all known populations observed in the sporadic meteoroid complex based on the latest and most precise data provided by Canadian Meteor Orbit Radar (CMOR). Our models using the latest theo- ries for cometary populations in the Solar System accurately describe observed sporadic background population. Our results are in agreement with observations provided by space probes IRAS and LDEF.
|
guest ::
