A meteorite that crashed in Australia 50 years ago has been confirmed to contain the oldest known solid material on Earth — stardust from a time before our planet even was even formed.
“These are the oldest solid materials ever found, and they tell us about how stars formed in our galaxy,” Philipp Heck, a curator at the Field Museum and an associate professor at the University of Chicago, said in a statement.
According to a study published in the journal Proceedings of the National Academy of Sciences, the materials are called presolar grains and are believed to be 4.6-to-7 billion years old. By comparison, our solar system, is only 4.5 billion years old, according to NASA. The grains became trapped in meteorites and remained unchanged.
“It’s the next best thing to being able to take a sample directly from a star,” Jennika Greer, a graduate student at the Field Museum, said in a statement.
So how did they determine the age? Once scientists were able to separate the presolar grains from the rest of the meteorite, they measured the grains’ exposure to cosmic rays.