Discovery of the oldest matter on Earth
Scientists have discovered the oldest substance on Earth by analyzing a meteorite.
They found dust particles in a space rock that fell to Earth in the 1960s, at least 7.5 billion years old.
The oldest particles of dust or dust formed in the stars long before our solar system was formed. A team of researchers has presented their findings in the journal Proceedings of the National Academy of Sciences.
When stars die, the particles that form in them bounce off into space. These ‘pre-solar particles’ then join the new stars, planets, moons and meteors.
“These are solid star patterns, real star dust,” said Philip Heck, lead author of the study and curator of the Chicago Field Museum and associate professor at the University of Chicago.
Researchers in the United States and Switzerland examined 40 particles in a part of the Merchison meteorite that fell in Australia in 1969 before the solar system came into being.
Jenica Greer, co-author of the study at the Field Museum and the University of Chicago, said:
“When all the pieces are separated, it is something like a paste and has a spicy characteristic that smells like rotten peanuts and butter.”
This foul-smelling paste is then dissolved in acid, after which only the stardust remains.
“It’s like finding a needle by burning a pile of glass,” said Philip Heck. To find out how old these particles are, researchers measured how long they were exposed to cosmic rays in space. These rays are high-energy rays that pass through galaxies and also enter solid matter.
These rays interact with matter and create new elements. As long as these substances are in front of the rays, they form as many elements. The researchers used a special form of the element neon (isotope) NE21 to determine the age of the particles.
Dr. Hack said: ‘I compare it to having a bucket in a rainstorm. I assume that it is raining continuously and the amount of water that accumulates in the bucket indicates how long the bucket has been in the rain.
The number of new elements added to it indicates how long the particles have been in contact with the cosmic rays. And it shows how old they are.
Some of the particles that preceded the formation of the solar system proved to be the oldest particles discovered.
Depending on how many cosmic rays they come in contact with, most of them are between 4.6 billion and 4.9 billion years old. By comparison, the Sun is 4.6 billion years old and the Earth is 4.5 billion years old.
However, the oldest discovery is about seven and a half billion (7.5) years old. More discoveries are expected.
Dr Heck told the BBC: ‘Only 10 per cent of the particles are more than 5.5 billion years old, while 60 per cent are’ young ‘particles between 4.6 billion and 4.9 billion years old and the rest are the oldest and most advanced. Are between
“I’m convinced that Merchantson and other meteors have a lot of pre-solar metals that we are still unable to identify,” he said.
Earlier, the discovery of particles before the earliest solar system was 5.5 billion years old on the basis of neon isotopes.
This discovery sheds light on the debate over whether new stars are formed at a constant rate or whether the speed at which new stars are formed increases over time.
Dr. Heck said: “Thanks to these particles, we now have direct evidence of the formation of stars in our galaxy over a wide period of time in the pattern of these meteors. This is an important discovery of our study.
The researchers also found that particles from the pre-solar system usually floated together in space in granola-like clusters.
“No one thought it was possible at this level,” explained Philip Heck.