Seminarium fizyki litosfery i planetologii
IGF, sala 109, Pasteura 7
Dr. Maria Gritsevich (Institute of Mechanics, Faculty of Mechanics and Mathematics, Lomonosov Moscow State University; Division of Geophysics and Astronomy, Department of Physics, University of Helsinki)
Modelling the atmospheric entry of meteoroids - a process bringing fragments of cosmic bodies onto the Earth
The study takes a new approach in modelling the fireballs' mass and otherproperties from the rate of body deceleration in an atmosphere, in additionto conventionally used luminosity. Proposed model is suitable to categorizevarious impact events in terms of meteor survivability and impact damage,and thus to analyze consequences that accompany collisions of cosmic bodieswith planetary atmosphere and surface. The different types of events,namely, formation of a massive single crater (Barringer, Lonar Lake),dispersion of craters and meteorites over a large area (Sikhote-Alin),absent of craters and meteorites, but huge damage (Tunguska) are consideredas illustrative examples. The proposed approach helps to summarize the dataon existing terrestrial impacts and to formulate recommendations for furtherstudies valuable for planetary defense. It also significantly increaseschances of successful meteorite recoveries in future. In other words, thestudy represents a 'cheap' possibility to probe cosmic matter reachingplanetary surface and it complements results of sample-return missionsbringing back pristine samples of the material. The presentation willinclude introductory part and thus I will try to keep it understandable andinteresting almost for everyone.