Stars are born when the gas, dust and heat combine just the right way. They can exist for billions of years before dying and expelling their key ingredients into space. When they die, they pitch the particles that formed in their winds out into space, and those bits of stardust eventually form new stars, along with new planets and moons and meteorites. Tiny grains isolated from a meteorite that fell in Australia were found to be between 5 and 7 billion years old, meaning they predate the Earth, the Sun and the solar system itself.
"These are the oldest solid materials ever found, and they tell us about how stars formed in our Galaxy", said Dr. Philipp Heck, a curator at the Field Museum of Natural History and a researcher in the Chicago Center for Cosmochemistry and the Department of the Geophysical Sciences at the University of Chicago. They are from silicon carbide, the first mineral formed when a star cools. "They're solid samples of stars, real stardust", says Heck.
The oldest grains were dated to more than 5.5bn years ago, long before the sun formed 4.6bn years ago.
But presolar grains are hard to come by.
While it's actually not unheard of for meteorites to contain grains of material that predate the Solar System - they're called "presolar grains" - they are rare, and hard to identify because the bits of material are so small, and deeply embedded in the rock.More news: Trump Receives Ovation From National Championship Crowd
A crew of researchers from the U.S. and Switzerland analysed 40 pre-describe voltaic grains contained in a portion of the Murchison meteorite, that fell in Australia in 1969.
It was extracted from the Murchison meteorite, which fell to Earth in the Victorian country town of Murchison in 1969.
In order to date the star dust, meteorite fragments were crushed into a paste which, according to scientists, had an unpleasant smell "like rotten peanut butter".
"This paste was then dissolved with acid, until only the presolar grains remained", Dr.More news: Giant tortoise Diego to return home after captive breeding program
"I always compare it to burning down the haystack to find the needle", Heck said. These rays are high-energy particles that travel through our galaxy and penetrate solid matter. By the type of isotope of helium and the type of isotope of neon we can then determine if they were produced by cosmic rays or not.
"The longer they get exposed, the more those elements form. Assuming the rainfall is constant, the volume of water that accumulates within the bucket tells you how prolonged it modified into as soon as uncovered", acknowledged Dr Heck. The majority were 4.6 billion to 4.9 billion years old - not as extreme but still hundreds of millions of years older than the solar system.
The meteorite was known to contain so-called presolar grains - minerals released by stars at the end of their life - but it is only now that the age of the sample has been verified.
In other words, he added, "there was a time before the start of the solar system when more stars formed than normal". The age distribution of the dust - numerous grains were concentrated at particular time intervals - provided clues about the rate of star formation in the Milky Way galaxy, the researchers said, hinting at bursts of stellar births rather than a constant rate.
"Some people think the star formation rate in the galaxy is constant", said Heck.More news: Retail Inflation Surges to 7.35% in December, Breaches RBI's Tolerance Level
"Thanks to these grains, now we hold yell evidence for a interval of enhanced big title formation in our galaxy seven billion years within the past with samples from meteorites".