The best studied meteorite and the 1969 Mexico wonder
September 22, 20246 Mins Read
January 8, 1969. The time is 1 am. The arrival of a fiery fireball instantly lit up the skies over the northern Mexican state of Chihuahua. The night sky was so bright that we could clearly see the tiny ants walking on the floor. I even had to cover my eyes with my hands to avoid the bright light.
the meteor
After passing through the atmosphere for a long time, the fiery rock finally exploded over the village of Pueblito de Allende. Its ruins spread over an area of about 250 km. Although the explosion of the cosmic object caused a lot of panic, its arrival at the end of the day is considered one of the most significant events in the history of the Earth. Because it was this object that brought the birth moment of our solar system through many paths.
Rocks that come to earth from space are called meteors. The entry time into the atmosphere is extremely dangerous for these cosmic guests. Because there they have to face great obstacles. Accelerating rocks continue to compress atmospheric air. Due to the contraction, the temperature increases gradually. As a result, the air surrounding the stones once burned.
And the seemingly featureless rocks turned into terrifyingly beautiful fiery meteorites. Most of the time they burn up in the atmosphere. However, if their size is large enough, some parts of the stones may come down to the surface even after burning. Then they were called meteorites.
By early 1969, there had been pent-up excitement in laboratories across the United States. Everyone was eagerly waiting for the Apollo missions. Moonstone will be brought to earth through this. At such a time, the Chihuahua meteorite caught the hands of scientists like rain without asking for much clouds. The meteorite was later named the Allende meteorite after the village.
It became famous instantly due to its dramatic arrival in the world. Scientists scrambled to collect its remains. Local residents also fully cooperated in this grand event. Researchers from the Smithsonian Institute in the United States alone managed to collect about 150 kg of stones. They were then distributed to 37 different laboratories in thirteen countries.
In total, it is possible to collect objects weighing more than two tons from the debris of the meteorite. Their mass ranged from 1 gram to 110 kg. Finding debris this large means the meteorite was at least the size of a car when it exploded. It has been called the 'Best Studied Meteorite' for successfully collecting and studying a significant amount of rocks .
By careful examination, scientists were convinced of a unique feature of the Allende meteorite. This is no ordinary rock from outer space. Rather, it belongs to the carbonaceous chondrite class. Only 5% of the total meteorites that have come to Earth from space belong to this category. Among these are the existence of very ancient objects from the time of the creation of the solar system. The largest such meteorite found on Earth so far is the Allende meteorite.
Radioactive elements are often found in the meteorites that reach the earth after passing through various obstacles. They decay spontaneously after a period of time in a completely natural way. That is, the nucleus of one element is converted into the nucleus of another element.
There is no opportunity to influence this process even by applying any kind of force from outside. It is not possible to know in advance exactly when a particular atom will be transformed in the process of radioactive decay. However, it is possible to predict how much time is required to decay exactly half of some radioactive atoms. Scientists have named this period half-life. Each radioactive element has a different half-life value.
The half-life of radioactive elements has an excellent practical application. If the half-life values of the radioactive elements in a meteorite are known in advance, it is possible to determine its (meteorite) age very easily. Let's give an example. One of the most well-known radioactive elements found in meteorites that hit Earth's surface is rubidium. Its mass number is 87.
That is, the total number of protons and neutrons in its nucleus is 87. Of these, 37 are protons, and the rest are neutrons. A neutron in a rubidium nucleus becomes a proton through the process of radioactive decay. As a result, the nucleus as a whole becomes a strontium nucleus of equal mass number. Thus, it takes a long time to transform exactly half of the total rubidium atoms present in a sample.
About 48.4 billion years. This time may seem like an eternity to us in terms of human life span. But considering the time of formation of planets or stars it is not much. If rubidium had a shorter half-life (eg several thousand years), then traces of rubidium would not be found in meteorites that reached Earth. Almost every atom of them would decay. On the other hand, if rubidium had a much longer half-life, the meteorites would not have the strontium needed to determine the age.
However, from the current number of rubidium and strontium atoms in a meteorite, scientists can easily calculate the number of rubidium atoms that have decayed since its (meteorite) birth. Later, by matching this information with the previously known rubidium half-life, they could instantly determine the meteorite's age.
This is exactly the method applied to the Allende meteorite sample that carried the message about the formation of the solar system. According to the results obtained, the meteorite's journey started about 4.56 billion years ago. It is very likely that the time when our familiar world made its debut in the universe.
Carbonaceous chondrite meteorites like Allende can give us a pretty good idea of the time of creation of the Earth and the Solar System. But it does not give much information about how exactly they emerged at that time. However, the scientists did not have to face much problem. By using the link of the star birth process with the information of the solar system creation period, they have found the original birth place of the planets. Let's get to know the matter from the very beginning.
Our Sun was born from a cloud of gas and dust floating in the galaxy. Such clouds are called nebulae. The temperature of that nebula was around minus 263 degrees Celsius. Not only the sun, but all the stars in the universe begin their birth process in such an extremely cold environment.
The mass of these gaseous clouds can range from 1,000 to 1 million times the mass of our Sun. They are mainly composed of hydrogen and helium gases. However, small amounts of heavy elements are also found. The gaseous nebula from which our solar system formed was probably more than 60 light-years in diameter!
advertisement
Because galaxies are always in motion, massive gas clouds are not uniformly distributed everywhere. In some places they are very tangled. In all those places, the concentration of gas is much higher than normal. Scientists named these places core. A strong gravitational force acts within the core. Due to its effect, the gases there are continuously compressed.
At the same time, more and more gas is drawn from the surroundings. As a result, the density of the core increases and the strength of gravity acting there. This process goes on almost forever. Due to continuous compression, tremendous pressure and heat build up inside the core. As a result, at one time the light started to spread. A protostar is born. Our sun, like all other stars in the universe, also emerged through this process. This rule has not been violated.
Dear reader, don't confuse protostars with full stars again. A balanced fusion reaction is a prerequisite for the start of the full star journey. In the beginning no fusion takes place between protostars or primordial stars. But under the influence of terrible strong gravity, the nuclei of hydrogen atoms that were once there came very close to each other and took part in fusion.
Two hydrogen nuclei combine to form a helium nucleus. Enormous energy is released as a by-product. Essentially, the equilibrium fusion reaction begins when the temperature of the protostar exceeds 10 million Kelvin. The time required to evolve from a protostar to a full-fledged star depends on its mass. The higher the mass, the faster fusion will begin. Stars like our Sun take about 50 million years to progress from protostar to protostar.
