Fifty years ago, in Australia, scientists discovered a meteorite that has been under study. The team has now found that the stardust inside the meteorite formed between 5 and 7 billion years ago. That makes it the oldest material ever found on Earth. Scientist Philipp Heck says that the material is the oldest ever found and that it tells about how stars formed in our galaxy.
The material that was found inside the meteorite is called presolar grains-minerals, and it was formed before the sun was born. Heck says that the material is a solid sample of a star noting the material is “real stardust.” The bits of stardust became trapped inside meteorites, where they remained unchanged for billions of years.
That makes them time capsules of the time before the solar system. Presolar grains are difficult to find. They are rare and found in only about 5% of meteorites that have fallen to Earth. They are also very tiny.
Scientists say that a hundred of the biggest grains could fit in the period at the end of a sentence. The meteorite fell in 1969 in Murchison, Victoria, and is known as the Murchison meteorite. The presolar grains for the study were isolated 30 years ago at the University of Chicago.
That isolation process starts by crushing the meteorite into a powder that turns into a paste that smells like rotten peanut butter. The paste is then dissolved with acid until only presolar grains remain. Once presolar grains are isolated, the team can figure out what type of stars they came from and how old they were. They did this using exposure age data, essentially how long they were exposed to cosmic rays. Some cosmic rays interact with the matter and form new elements; the longer they are exposed to them more elements form. The tests showed that some gains were older than the Sun and Earth.