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Tech & Science Stardust found inside Murchison meteorite in Victoria is oldest-known solid material on Earth

13:35  14 january  2020
13:35  14 january  2020 Source:   abc.net.au

Oldest stuff on Earth found inside meteorite that hit Australia

  Oldest stuff on Earth found inside meteorite that hit Australia Oldest stuff on Earth found inside meteorite that hit AustraliaA meteorite that crashed into rural southeastern Australia in a fireball in 1969 contained the oldest material ever found on Earth, stardust that predated the formation of our solar system by billions of years, scientists said on Monday.

The oldest solid material ever found on Earth has been discovered inside a meteorite that landed near Murchison 50 years ago.

Granules, shed by dying stars over 5bn years ago, are oldest known solid material on Earth . Stardust that formed more than 5bn years ago, long before the birth of the Earth and the sun, has been discovered in a The research on the Murchison meteorite is published in the journal PNAS.

Presolar grains found in the Murchison meteorite may be from the clouds of dust and gas around ageing stars like the pictured Egg Nebula. (Supplied: NASA, W. Sparks (STScI) & R. Sahai (JPL) & inset Janaina N. Avila)© Provided by ABC NEWS Presolar grains found in the Murchison meteorite may be from the clouds of dust and gas around ageing stars like the pictured Egg Nebula. (Supplied: NASA, W. Sparks (STScI) & R. Sahai (JPL) & inset Janaina N. Avila)

A 7-billion-year-old grain of stardust — older than our solar system — has been discovered inside a meteorite by an international team of scientists

This makes it the oldest solid material found on Earth the researchers said. It's even older than our Earth and the Sun, which are 4.5 and 4.6 billion years old respectively.

And this stardust has an Australian connection.

It was extracted from the Murchison meteorite, which fell to Earth in the Victorian country town of Murchison in 1969.

A meteor that struck Australia brought indestructible stardust more ancient than the sun. It's the oldest solid material ever found on Earth.

  A meteor that struck Australia brought indestructible stardust more ancient than the sun. It's the oldest solid material ever found on Earth. In 1969, a 4.6-billion-year-old meteorite struck Murchison, Australia. The meteorite contained fragments of stardust called presolar grains. This stardust is between between 5 billion and 7 billion years old - older than the sun and our solar system. Most of the grains in the Murchison meteorite came from various stars that formed around the same time. This suggests stars are born in bursts, rather than at a constant rate. Visit Business Insider's homepage for more stories. Meteorite fragments found in Australia appear to have brought rare, interstellar passengers to Earth: pieces of stardust older than the sun.

A meteorite that crashed into rural southeastern Australia in a fireball in 1969 contained the oldest material ever found on Earth , stardust that The oldest of 40 tiny dust grains trapped inside the meteorite fragments retrieved around the town of Murchison in Victoria state dated from about 7

A meteorite that crashed into rural southeastern Australia in a fireball in 1969 contained the oldest material ever found on Earth , stardust that predated the The oldest of 40 tiny dust grains trapped inside the meteorite fragments retrieved around the town of Murchison in Victoria state dated from

"This meteorite is really a treasure trove for science," said cosmochemist Philipp Heck, of the Field Museum in Chicago, who was the lead author of the paper published today in the Proceedings of the National Academy of Sciences.

How do you date stardust?

First of all, you have to get the stardust out of the meteorite.

The stardust is made of grains of presolar silicon carbide, a mineral formed before our solar system was born.

"The presolar grains are a tiny fraction of meteorites like Murchison, only parts per million," Dr Heck said.

"We use a chemical recipe of different chemical reagents, mainly acids, to dissolve away everything else, and then we extract those minerals.

"We image them, we analyse their isotopic composition to find out what type of star they came from, and then we can start our study … to find out how old they are."

Interstellar Stardust Found Inside Australian Meteorite Is A Staggering 7 Billion Years Old

  Interstellar Stardust Found Inside Australian Meteorite Is A Staggering 7 Billion Years Old A meteorite that crashed into Australia back in 1969 contains stardust dating back some 7 billion years, predating the formation of Earth by 2.5 billion years. The remarkable discovery offers a snapshot of the conditions that existed long before our solar system came into existence. Ancient grains found inside the Murchison meteorite have been dated to between 5 billion and 7 billion years old, according to new research published in Proceedings of the National Academy of Sciences. The new paper was led by astronomer Philipp Heck from the University of Chicago.

Researchers have discovered the oldest material on Earth – and it’s not from Earth . Tiny grains from a meteorite that fell in Australia were found to be between 5 and 7 These high-energy particles flit around space and can pass through solid matter, creating new elements inside the existing minerals

THE oldest material ever found on Earth has been discovered lurking in a meteorite that fell to our planet. Ancient stardust dating back seven billion years But the Field Museum has the largest portion of the Murchison meteorite , a treasure trove of presolar grains that fell in Victoria , Australia, in 1969.

The ratios of carbon-12 to carbon-13 isotopes in these grains were a perfect match to what astronomers have observed in the clouds of dust and gas around ageing stars like the Egg Nebula and the Ring Nebula.

But unfortunately, traditional dating methods geochemists use on Earth don't work when you're dating stardust, Dr Heck said.

Instead the researchers measured how long the grains have been exposed to the cosmic rays shooting through the universe.

When a cosmic ray —a stream of high energy particles, mainly protons and alpha particles — penetrates a presolar grain it occasionally splits one of its carbon atoms into fragments.

By counting all the fragments produced by the cosmic rays, and knowing how often they are produced, scientists can work out how old the stardust is.

"Each grain probably came from a different star," Dr Heck said.

"We have some grains which are a billion years older than the Sun, making them 5.5 billion years old … a few grains that are 2 billion years older and we have one grain that is 3 billion years older [than the Sun].

One of the biggest meteorite crashes in Earth's history flung debris across 3 continents 800,000 years ago. Scientists finally found the crater.

  One of the biggest meteorite crashes in Earth's history flung debris across 3 continents 800,000 years ago. Scientists finally found the crater. A 1.2-mile-wide meteorite struck Earth 800,000 years ago. Scientists have long known when the space rock hit and how far debris scattered, but they couldn't find the spot where the meteorite made landfall - until now. A new study suggests the meteorite struck present-day Laos, and its impact crater lies beneath a volcanic field. Visit Business Insider's homepage for more stories. About 800,000 years ago, a monster space rock struck the Earth hard and fast. The impact of the 1.2 mile-wide meteorite flung debris across 10% of the planet's surface.

The oldest thing ever found on Earth has been discovered by scientists Tiny specks of stardust , dating back seven billion years, have been uncovered in a meteorite which landed in Victoria “These are the oldest solid materials ever found , and they tell us about how stars formed in our

Some of that stardust ended up in a meteorite that landed in Murchison , Australia, in 1969. And according to new research, it's officially the oldest known solid material on Earth . The team found that the meteorite contained particles older than 5.5 billion years and possibly as old as 7 billion years.

"I'm pretty sure than Murchison contains older minerals, we just haven't found them yet."

The cosmic ray method doesn't give us an absolute age of the stardust, said planetary scientist and meteorite hunter Phil Bland of Curtin University, who wasn't involved in the research.

But it's our best approximation so far.

An astronomical baby boom

The ages of these grains of stardust isn't only important in themselves, but also because of what they tell us about the evolution of our galaxy.

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

"In order to explain our age distribution, where we have many more younger grains that we would otherwise expect, we have to explain this by this dust forming from more stars than normal," he said.

"We came to the conclusion that about 7 billion years ago there must have been an episode of enhanced star formation, probably about 50 per cent more stars formed than normal."

Or in other words, a star-making baby boom.

And that's a fascinating result, Professor Bland said.

"That peak in star formation about 7 billion years ago … is really interesting because there's a target that other people can chase," Professor Bland said.

Now he said, we need more statistics from a different meteorite.

"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?'."

For Dr Heck, this latest research is one of the most exciting studies he's worked on, but he's sure it won't be the last.

"Murchison is so important, and so rich and full of surprises," he said.

"I really want to emphasise that without the foresight of the people of Murchison we wouldn't have access to this wonderful sample … so this has really made a big, big difference."

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