The appearance of these meteors was the result of a series of space collisions that occurred 4.5 billion years ago.
To such conclusion scientists from the universities of Munich, Bayreuth and London, stimulirovat in experiments with high blood pressure appearance of all known pallasites. As the authors of the study, first as a result of these collisions of small iron meteorites mixed with rich olivine content in the mantle of larger asteroids. Then, after billions of years, is quite another meteorite knocked out part of this mixture from the surface, sending them into outer space.
Some of these parts eventually ended up on the Ground, where he was called “pallasites” – named after the academician P. S. Pallas, who described the first such meteorite, found in 1749, 200 kilometers from Krasnoyarsk. The history of the origin of pallasites, opened now the German and British scientists, explains an unusual and attractive arrangement of these stones — they consist of green-brown crystals of olivine melted into iron and Nickel.
The location of the different materials in the same meteorite and arising out of the structure scientists call the texture, and found on Earth pallasites show a lot of textures. According to the authors of the study, they were able in the laboratory to recreate all the textures of known pallasites.
This was done using two powerful high-pressure press — one, located in the Bavarian geological Institute and the second at the Technical University of Munich. “Using these tools we can very realistically simulate the processes that led to the emergence of meteorites, asteroids and planets, – says one of the study authors Daniela Silva Souza from the University of Bayreuth. – To explain how the collision of asteroids led to the advent of the pallasites, we have reproduced the pressure and temperature which have been during these processes: samples of olivine and iron we are put under pressure in one gigapascal at a temperature of 1300 °C.