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Rare ‘alien’ isotopes in Earth’s crust point to latest brush with disastrous event



Below, in the periodic table, you will find a list of the heavy elements that arise in the chaos. The chaos you might encounter in an exploding star or a collision between two neutron stars.

Physicists have discovered a pair of large radioactive isotopes in a sample of the deep sea crust pulled from 1,500 meters (nearly 5,000 feet) below the Pacific Ocean.

We expect to see heavy elements in the swirling dust and gas that formed our planet years ago – but most likely decay in a more stable form before. Therefore, finding a sample in the Earth’s crust close to the surface Today This raises an interesting question.

These findings can tell us about a thing or two about catastrophic cosmic events that occurred within a few hundred light-years from Earth and more recently in our geological history. It can also shine in the form of atomic heavyweights.

You can see that creating atoms requires a lot of energy. Protons can squeeze into helium under the gravitational force you encounter in stars. But the fusion of stars will only take you so far. To make a chubby animal like plutonium, you will need a kind of energy that can fire a machine gun̵

7;s neutron.

There are certain conditions in the universe that This ‘rapid neutron capture’, or r process, can take place, including the merging of supernovas and neutron stars.

In the history of the universe, many stars have crashed and emerged to spew out thick dust of iron, uranium, plutonium, gold and other fat atoms throughout the galaxy. Therefore, it is expected that planets like Earth will scoop up a lot.

But not all elements are born the same. The variation in the number of neutrons makes some of them more stable than others. For example, iron 60 is a type of isotope. “Blink and you miss it” if you look at the cosmic scale, with a half-life of just 2.6 million years before it decays into nickel.

The search for this short-lived isotope on our planet today, especially in the Earth’s crust not far from modern fabrication processes, will indicate a newly-received delivery of iron from the universe.

Iron 60 has appeared in rock samples, dating back a few million years. It is also seen in materials brought back from the surface of the moon.

But to understand the specific types of r processes that produce these pieces, it pays to see what other isotopes fall with them.

Anton Wallner, a physicist at the Australian National University, led a team of researchers to search for new samples of 60 iron to see if they could identify other nearby heavy isotopes.

What they found was plutonium 244, an isotope with a half-life of just 80 million years, stable for plutonium. But it’s hardly the element you’d expect to stick with, as our world was assembled 4.5 billion years ago.

In total, the team discovered two different inflows of 60 steel that had to arrive within the last 10 million years. Both samples came with a small amount of 244 plutonium. But significantly in each sample in a similar ratio.

Finding these things together adds more detail than separating them. The plutonium content in them was lower than would be expected if the supernova was primarily responsible for its production, pointing to involvement from other r processes.

The thing behind this particular extraterrestrial dust roll is still in our imagination for now.

“The story is complicated,” Wallner said.

“It is possible that this plutonium-244 was produced from a supernova explosion, or it could have been dropped from a much older event. But more exciting, like a neutron star explosion. “

By measuring radioactive fuses sequentially and making some assumptions about the astrophysics behind their distribution, the researchers speculate that the production of iron 60 is compatible with two to four supernova events to occur. Between 50 and 100 parsecs (approximately 160 and 330 light years) of the Earth.

This is not the first time that iron 60 has identified a supernova that has occurred close to a danger in past history.

By looking at isotopes associated with other elements, we can create a signature that tells us more about the collision conditions of the neighborhood in the millions of years before humans began to pay close attention.

Although it will take more time to hunt for the alien isotopes.

“Our data may be the first evidence that supernovae can produce plutonium-244,” Walner said.

“Or maybe it was already in the interstellar medium before the supernova was extinguished and it was pushed across the solar system with the supernova ejected.”

The research is published in science.


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