Scientists have discovered the oldest solid material ever found on Earth from a meteorite that fell in Australia about 50 years ago.
The material that the researchers examined are called presolar grains – or stardust – particles from a star that can eventually form new stars, along with new planets, moons and meteorites.
This particular sample is about five to seven billion years old and predates the sun, which the Field Museum says is about 4.6 billion years old.
“This is one of the most exciting studies I’ve worked on,” said Philipp Heck, lead-author of the study published in the peer-reviewed Proceedings of the National Academy of Sciences and associate professor at the University of Chicago.
The stardust was preserved in a meteorite that fell in Murchison, Victoria, in 1969. Researchers at the University of Chicago have been studying the material for about 30 years.
Presolar grains are extremely rare and were found in only about five percent of meteorites that have fallen to Earth, according to the Field Museum. They are formed when a star dies and can tell scientists more about the history of stars.
“It’s the next best thing to being able to take a sample directly from a star,” said Jennika Greer, a graduate student at the Field Museum and the University of Chicago, and co-author of the study.
From examining this material, scientists were able to deduce that there was a “baby boom” period of stars forming in space about 7 billion years ago. This finding contradicts a highly contested debate between experts in the field.
“Some people think that the star formation rate of the galaxy is constant,” Heck said. “But thanks to these grains, we now have direct evidence for a period of enhanced star formation in our galaxy 7 billion years ago with samples from meteorites.”
Heck said there’s still a lot of questions surrounding presolar grains and the early solar system but looks forward to more discoveries furthering our knowledge of our galaxy.