At the bottom of the periodic table you will find a list of the heavy elements that cause chaos. The kind of chaos you might find in a stellar explosion, or a collision between two neutron stars.
Physicists have found a pair of large radioisotopes in samples of deep ocean crust pulled from an altitude of 1,500 meters (nearly 5,000 feet) below the Pacific Ocean.
We expect to see many of the heavyweights in the dust and gas swirl that formed our planet thousands of years ago – but most of them should have degraded into more stable forms long before. So look for examples in the Earth’s crust near the surface Today This raises some interesting questions.
These discoveries can tell us a thing or two about catastrophic cosmic events that occurred within a few hundred light years from Earth, and relatively recently in our geological history. It can also highlight the way in which the atomic weight of the weight is formed.
As you can see, building atoms takes a lot of energy. Protons can be compressed into helium under the kind of gravity you find in a star, but stellar fusion will only get you far. To build a massive mass like plutonium, you need some kind of energy that can fire off bursts of neutrons.
There are several conditions in the universe under which this “fast neutron capture” or r process can occur, including combining supernovae and neutron stars.
Throughout the history of the universe, many stars have disintegrated and sprung up, dropping dense dust of iron, uranium, plutonium, gold, and other fatty atoms all over the galaxy. So hopefully a planet like Earth has taken up a good amount of it.
However, not all elements produce the same thing. The difference in the number of neutrons makes some more stable than others. Iron 60, for example, is the kind of isotope that would “flash and skip” if you looked at it on a cosmic scale, with a half-life of only 2.6 million years before decaying to nickel.
Finding these short-lived isotopes on our planet today – especially in its crust, beyond the reach of modern synthetic processes – would mean a relatively recent shipment of fresh iron from the universe.
Iron 60 has appeared in previous rock samples, which are only 2 million years old. As seen in the material brought back from the lunar surface.
But to get a good idea of the specific type of r process that produces this sample, it can be helpful to know what other isotopes rain with.
Physicist Anton Waller of the Australian National University led a research team to search for new samples of Iron 60 to see if they could identify other isotopes of the heavy element nearby.
What they found was plutonium 244, which is an analogy The half-life is just over 80 million years Stable for plutonium, but not the kind of element you’d expect since our planet met 4.5 billion years ago.
In all, the team found 60 different streams of iron that must have arrived in the last 10 million years. Both samples were accompanied by small amounts of plutonium-244, each in equal proportions.
Finding them together adds more detail than searching for one of them separately. The amount of plutonium in it was less than would be expected if a supernova was primarily responsible for its production, indicating the contribution of other r processes.
In fact, what is behind this torrent of space dust is up to our imagination for now.
“The story is complicated” Says And that fire.
“It is possible that this plutonium-244 was produced in a supernova explosion or a remnant of a much older, but much more interesting event such as a neutron star explosion.”
By measuring each radiation valve and making some assumptions about the astrophysics behind its distribution, the researchers speculate that Iron 60 production corresponds to two to four supernova events located between 50 and 100 parsecs (about 160 and 330 light years) of Earth.
This is not the first time Iron 60 has indicated an extremely dangerous supernova in recent history.
By looking at isotopes associated with other elements, we can slowly build signatures that tell us more about the explosive conditions of collision in our region in the millions of years before humans began to notice them.
However, further research on space isotopes will be needed.
“Our data could be the first evidence that supernovae are actually producing plutonium-244,” Says And that fire.
“Or maybe it was in the interstellar medium before the supernova exploded, and was propelled through the solar system with supernova projectiles.”
This research is published in Science.
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