Four and half milliard years before the world was a burning sphere has arisen a small asteroid somewhere in solar system. The small asteroid collided with another orb about six millions years ago. The impact destroyed the small asteroid for pieces which went to its self way; some of them went to our solar system. Some slivers come along the aerospace 6-th of May 2000 and ten thousands people from North Moravia become to be whiteness of the exceptional happening which entered into astronomy history.
Thousands of falling stones, ten a tunes of mass from far and near space has fallen on world surface. Scientists know its constitution and made methods how to accurately describe and sort them. Chondrits, achondrits, space irons, stony irons, glass meteors and others you can see in Universities, Museums and in private collections also. Theirs names are usually after impact point. The falling stone from Beskydy is not an exception; its name is Morávka.
We know a lot about meteors; what we don’t know is information about space history. When and how they arise; from where they arrive on which trajectory they move, how they get in atmosphere and who they behave in.
Meteors with known rise and trajectory astronomers call as falling stones with genealogy. Scientists from whole world described six meteors only till this time and an institute in Ondřejov makes here important part. At the beginning of 60s Czech astronomers started to build a net for bolides photographing; astronomers call like that a meteorite orbs which have during transit high intensity of shining and are good observable.
The bolides net scans every night the sky if is not cloudy and if some bolide transits, the scientists have an accurate coordinates of its trajectory; and than they can count where the meteor comes from and where will fall.
First success was in 1959 near by Příbram. The first falling stone with genealogy in the world calls Příbram and the biggest of four found piece has about four and half kilograms. In 1970 was found meteor near to Lost City in American Nebraska through the use of plains bolides net. Seven years later was found six pieces by Canadian scientists in snow landscape near to Inisfree town. A rarity was a case in New York State where in 1992 fell a 12kg meteor right on a park car in Peekskill town. The last for now is a falling stone with genealogy found in Alps on Austria-German boundary last spring.
The Meteor Morávka transit through aerospace in a day so was good visible and independently from each other several people made video of it from various places (Janov, Kunovice, Velká Javorina). Those daily videos supply the nightly bolides net. Found pieces specified the trajectory. The orb transit made big noise also. People say it sounded like thunder of gunnery and some of them thought that it was crashing in industrial plant. The surging brings quakes of Earth's surface what noted Seismic Station in Ostrava area; similar note came from Freiung Station in Bavaria, where control The Nuclear Tests Ban for whole world. Valued informations afforded by American satellite used for the same function. From passing observers came about five hundred reports to astronomic institutes. Laws of nature and scientist's skills allowed to specify trajectory and history of movement and to determine the rise so the meteor Morávka can get the genealogy.
Astronomers from the interplanetary mass department in Ondřejov took the view that The Morávka orbited on its trajectory in solar system for about six millions years; the real old of the mineral is four and half milliards years and this is time when the galaxy was shape only. The Morávka orbit around The Sun as The Earth and their trajectory many time crossed but at different time, after The Morávka separated from the mother asteroid. The Morávka's orbit time around The Sun was about two and half year.
At the time of The Morávka meteor and The Earth meet, so on Saturday 6-th of May 2000, has the meteoric orb about two tones and one meter diameter. Scientists think that before The Morávka enter in to atmosphere was not a one piece but cohesive orb block which heft about hundreds kilograms; As twenty hundred kilos heft bags moving in one huddle.
Basic chemical constitution of falling - stone was formed by mixture of iron and magnesium, similar mineral was never fount in The Earth. All mass with such constitution and structure arrived always from space. Iron is element, that is in falling - stones principally most frequently. At the time of first Republic folks picked up a metal rock in the Orava forests and sell them to traders. An estimates talked about hundreds of kilograms of uncommon falling - stones, which ended in ironworks at that time.
Astronomers studied Morávka's trajectory except its rise and how it behaved while transit atmosphere. Before entrance to the atmospheres the orb flew at a speed about twenty kilometres per second. The braking factor began heat it up, and it disintegrated and a part of the mass completely evaporate by the heat. Thereby happened that Morávka begun shine on the sky. Gradually the bolide cool down and than flame out.
All three found shivers are in astronomical institute property today, which bought them from finders. Nearly after three years of researching the institute lend them to National Museum in Prague, where they will be in permanent mineralogical collections exposition, in the same way as first world's falling - stone with genealogy called Příbram.
However three pieces of Morávka in The National Museum aren't the only one, which people found in Beskydy. About a year after the falling - stone falls was detected other two pieces thanks of new locators. One is in private proprietorship in Ostrava, second wandered to Vienna.
Informations were assumed from article FALLING - STONE WITH GENEALOGY, Hospodářské noviny(economic newspaper), magazine Víkend dated 18-th of April 2003, author of the text Tomáš Netočný, photo Jan Šilpoch, ČTK
|
|