Scientists have discovered in a piece of meteorite the oldest material ever found on earth. This is star dust that is probably between 5 and 7 billion years old.
The material was in a meteorite that crashed to Earth in Australia fifty years ago. The oldest of the forty small dust particles found in the meteorite are about 7 billion years old, about 2.5 billion years before the sun, the earth and the rest of the solar system were formed.
The dust particles are each 2 to 30 microns (1 micrometer is a thousandth of a millimeter). Once the tiny particles made up of a star, but when it died, the pieces were hurled into space. Those pieces of star dust then formed a meteor.
The meteor actually used the meteor as a kind of time capsule. In the rock the so-called “presolar grains” could travel through space for billions of years and eventually end up on earth.
Baby tree in the Milky Way
According to the scientists, the discovery tells something about the formation of our galaxy. The fact that so many particles from the same period were found, would indicate that a birth wave of stars occurred in the Milky Way 7 billion years ago.
The oldest material found on Earth so far was around 5.5 billion years old. Even then it was about presolar grains in a meteorite. The oldest mineral found on Earth was found in an Australian rock and was 4.4 billion years old, one hundred million years after the planet was formed.
The findings from the research have been published in the scientific journal Proceedings of the National Academy of Sciences (PNAS).
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