In 1969, over the Australian village of Murchisonscientists observed a very unusual phenomenon. It was then that a 100-kilogram meteorite exploded in the sky, particles of which were scattered in a radius of several kilometers. Scientists managed to get about 52 kilograms of the space object and in the 1990s, microscopic particles of a mineral called silicon carbide were found inside it. Researchers came up with the assumption that they are dealing with the so-called pre-solar grains - interstellar substances that formed long before the appearance of the Sun and the Earth. In those days, it was not possible for them to calculate the exact age of the materials found, but recently they finally managed to do this. As scientists expected, they were dealing with the most ancient materials that have ever appeared on our planet.
About the discovery of a group of scientists from the USA, Switzerland andAustralia was told in a scientific publication called Proceedings of the National Academy of Sciences. By grinding the found samples of the Murchison meteorite, the researchers were able to extract 40 particles of pre-solar grains. Determining their age turned out to be a very difficult task, but scientists nevertheless did this using data on the time of exposure to grains of cosmic rays. Under this term, it is customary to understand the flows of high-energy particles that fly through our entire galaxy and penetrate solids. It is known that when interacting with these rays, new elements are formed in the pre-solar grains and the longer the interaction takes place, the more these substances are ultimately observed.
Interesting fact: one of the fragments of the Murchison meteorite pierced the roof of one of the village houses
Oldest material on earth
Having studied the data on the interaction of grains withcosmic rays, scientists have discovered that they formed between 5 and 7 billion years ago. Based on the fact that our solar system was formed 4.6 billion years ago, it turns out that particles found by scientists formed long before the appearance of the sun. According to scientists, the materials found at the moment are the only evidence available to humanity about the existence of a period preceding the emergence of the Sun and the Earth.
Do you know which microbes eat only fallen meteorites?
In general, similar materials can be foundinside many meteorites that fell on our planet. Only now it is extremely difficult to detect and recognize them, because they are embedded deep into space objects and have microscopic dimensions. The fact that scientists managed to extract them from the Murchison meteorite is a great success. Thanks to the study of these particles, scientists can put forward various assumptions about the evolution of the Universe and tell a lot of interesting things about how our planet was formed.
This is one of the most exciting studies overwhich I worked with. These are the oldest solid materials ever found, and they can tell us how stars formed in our galaxy, ”shared one of the authors of the study, named Philip Heck.
You can also read about the Murchison meteorite inour material about whether the Earth could have formed with the life that already existed on it. After all, who knows - perhaps our planet was originally inhabited by living beings and we simply don’t know about it?