Prague – Researchers from Charles University (UK) in collaboration with scientists from France, the USA and the European Southern Observatory have revealed the origin of 70 percent of meteorites that fall on Earth. Computer models by scientists from the Astronomical Institute of the UK showed that the most abundant source of meteorites are the families of asteroids bearing the names Massalia, Koronis and Karin. Meteoroids, some of which then fall to Earth as meteorites, are created during collisions of asteroids orbiting the Sun, which took place tens of millions of years ago. Two studies on the origin of meteorites were published in mid-October by a prestigious scientific journal Nature. Already website this was stated by the Faculty of Mathematics and Physics of the Charles University.
The meteorite material formed from dust long before the Earth was formed, just two million years after the Sun formed 4.567 billion years ago, the researchers said, citing radiometric measurements of the meteorites. Asteroids were formed from the material, whose orbits around the Sun cross, and once every few million years the ten-kilometer bodies collide and shatter. This creates meteoroids, which then orbit the Sun independently. “Czech researchers have now succeeded in creating the most complete model to date describing the dynamics of asteroids in the main belt and near the Earth, as well as the origin of meteoroids of various types,” said the website of the Faculty of Mathematics and Physics of the UK.
Asteroids break into fragments when they collide with each other. The first fragmentation took place about 40 million years ago, the second 7.6 million years ago and the third 5.8 million years ago, said Miroslav Brož from the Faculty of Mathematics and Physics of the Charles University. The source of meteorites falling on Earth are mainly the Massalia, Koronis and Karin families of asteroids. “Altogether, this is how we managed to explain the origin of 70 percent of all meteorites. These are the same types of meteorites that were already observed by the ancestors of man,” added the scientists from the Faculty of Mathematics and Physics of the Charles University.
Their calculations were preceded by the work of astronomers Michaël Marsset from the European Southern Observatory and Pierre Vernazza from the University of Aix-Marseille, France. With the help of spectroscopy in a telescope, they classified asteroids according to the minerals they contain, similar to how it is done with meteorites. Researchers from the US Massachusetts Institute of Technology (MIT) and several other institutions also participated in the two studies published in the journal Nature. According to researchers from the Faculty of Mathematics and Physics, the results are consistent with a number of other observations.
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Source: www.ceskenoviny.cz
