Oldest Material On Earth Has Been Just Discovered

Eloise Marshall
January 14, 2020

The ratios of carbon-12 to carbon-13 isotopes in these grains were a ideal match to what astronomers have observed in the clouds of dust and gas around ageing stars like the Egg Nebula and the Ring Nebula. Since presolar grains are formed when a star dies, they can tell us about the history of stars.

While some astronomical models assume stars form at a constant rate, Dr Heck and his colleagues' work shows that isn't the case.

In the future, Heck and others will isolate more presolar grains from meteorites such as Murchison and continue to date them using the cosmic ray technique.

A new study of the presolar grains found on the Murchison meteorite was published yesterday by the National Academy of Sciences journal.

"These are solid samples of stars, real star dust", said Professor Heck.

To study the presolar grains, researchers initially isolated the material from the rest of the meteorite.

Philipp Heck, curator of meteorites at Chicago's Field Museum which has a piece of the meteorite in its collection, examined the pre-solar grains. Locals came upon several fragments of the meteorite, the largest of which, with a mass of 680 grams, crashed through a roof and landed in a pile of hay.

"It starts with the crushing of the meteorite fragments into powder", said Jennika Greer, study co-author and graduate student at the Field Museum and the University of Chicago.

College Football Playoff National Championship Uniform History
Lindsey Graham, R-S.C., who predicted a championship for Clemson , flew with Trump aboard Air Force One to Louisiana for the game. He also was jeered and booed at a World Series game in Washington.


This "meteorite-rotten peanut butter paste" was then dissolved with acid, until only the presolar grains remained.

"What I would do now is pick another sample and go through the same process and say 'Okay, do we find that same distribution of stuff or is there something weird about this one?'". So measuring the carbon and silicon isotopes each grain contains allowed Heck's team to determine what type of star it came from. Neon-21 is a form of the chemical element that builds up when silicon carbide is bombarded with high-energy particles called galactic cosmic rays in interstellar space. "These are the oldest solid materials ever found, and they tell us about how stars formed in our galaxy".

Presolar grains have been discovered in other meteorites before, such as the Hypatia stone and LAP-149, but their ages weren't able to be pinned down. The grain age range has also intrigued scientists: the majority was 4.6 billion to 4.9 billion years, suggesting that an exceptional crop of new stars has formed in the Milky Way il about 7 billion years ago - the lifespan of a star is usually a few billion years. "This is one of the key findings of our study". The oldest known minerals that have formed on Earth are found in the rocks of the Australian Jack Hills, which formed 4.4 billion years ago, 100 million years after the planet was formed.

The stardust represented time capsules dating to before the solar system.

The researchers also realized that pre-describe voltaic grains in general drift via house stuck collectively in dapper clusters, adore granola.

The researchers learned that some of the presolar grains in their sample were the oldest ever discovered on Earth. "But thanks to these grains, we now have direct evidence of an improved star formation period in our galaxy seven billion years ago with meteorite samples". "No one thought this was possible at that scale", Philipp Heck explained. But their exact age hadn't been determined until now. Stardust is the remnant material left behind after the death of a star in a supernova.

"It's so exciting to look at the history of our galaxy".

Other reports by

Discuss This Article

FOLLOW OUR NEWSPAPER