Traces of rare forms of iron and plutonium have been found at the bottom of the Pacific Ocean after some catastrophic space has created this radioactive material and sent rain down on our planet.
Extraterrestrial debris reached Earth within the last 10 million years, according to the journal. scienceWhen it hit the Pacific Ocean and fell nearly a mile to the bottom, the material was merged into the rock layers that a Japanese oil exploration company later pulled up and donated to researchers.
“The plutonium was just known to be remarkable,” said Brian Fields, an astronomer at the University of Illinois at Urbana-Champaign, who was not part of the research team. “Right now we only have a very small amount of material, and then we̵7;re talking hundreds of atoms here. But we should be grateful for that because it is rebuilt from explosive stars. ”
New examples like these could help scientists understand how the universe forged heavier elements such as gold, platinum, uranium and plutonium. “These are elements that we remain a mystery,” said Anton Wallner, a physicist at the Australian National University in Canberra who leads the new international team. “We don’t know exactly where and how it is made in different areas.”
Finding the source of these elements is a big deal for astronomers who quite already know where the rest of the periodic table came from. For example, hydrogen and helium were born in the Big Bang and elements like carbon and oxygen in the stellar core, that’s why beloved astronomer Carl Sagan said. “We are made of interstellar objects”
Astronomers believe that the heaviest elements must come from environments more extreme than everyday stars. One possibility is when a massive star passes its death and explodes into a supernova.
The powerful blast sends out elements that pop out in all directions, and if a supernova is nearby, Fields says, “all of these elements that happen in a supernova will deliver to us and sprinkle it on our heads. Truly ours. ”
About 25 years ago, he and a few colleagues suggested a way to find that kind of litter. They point out that the supernova creates a stable component. But it also makes an unstable form of radioactive elements that persist millions of years before decay.
These specific atoms will survive long enough to find their way to Earth from explosive stars and have been discovered by scientists – but they are not mistaken for the stable elements that have existed since Earth was formed in many ways. Billion years ago
Researchers hunted these treasures from outer space and soon began to find so-called iron-60 in rocks, deep sea, Antarctic snow and even samples from the moon.
All these findings suggest that some stellar explosions, possibly supernovae, occurred in an area close to Earth’s cosmos some 3 million years ago and littered that area with radioactive iron.
Recent studies of iron incorporated into the slowly growing deep-sea shale confirm that idea – but also suggest that another amount of interstellar iron arrived about 6 million years ago. There is only one exploding star, but two, “Fields said.
Moreover, in this study, the researchers were able to detect the characteristic plutonium-244 atoms that do not exist naturally on Earth. By looking at the amount of plutonium and iron in the shale, they were able to compare what they saw with models predicting the production of these elements by cosmic events such as supernovae.
Their analysis suggests something else needs to be involved in addition to a supernova, Wallner said.Astronomers have long suspected that a collision between two neutron stars could be a source of another heavy element.
“Our data suggest that both situations may be necessary,” Wallner said. It’s both. It’s a supernova explosion that produces these heavy elements. But also the gathering of neutron stars or other very rare events. “
Hendrik Schatz, a physicist at Michigan State University who was not part of the research team, said the new results were remarkable. While plutonium’s tantalizing speech has been found in this form, he said, “We always hope that enough people will get enough samples and find that in the deep-sea sediments we have been waiting for a long time.”
In his view, the new findings add to other evidence that the heaviest elements, such as plutonium, cannot be created from conventional old supernovas. “It has to be an otherwise rare event,” Schatz said. “There is evidence to point to multiple sources. Combining neutron stars may be more important than one, but as of now, they do not appear to be able to achieve this. Explain all observations “
Measuring other types of short-lived elements could ultimately help sort through all of this, Fields said, and he noted that while stellar explosions could occasionally sprinkle our planet with stardust. But nowadays, there is no such thing as large enough to go supernova and send out the radiation that devastates living things our way.
“These stars are not fragile, we know exactly where they are,” Fields said, “and no one is threatening us today.”
The previous caption said the photo shows Cassiopeia A, a supernova remnant. In fact, it shows the remains of Kepler’s supernova.
AILSA CHANG, host:
Scientists have found an incredible find at the bottom of the Pacific Ocean – a rare type of plutonium atoms. This plutonium was created in a cosmic catastrophe and it rains on Earth, NPR’s Nell Greenfieldboyce reports why researchers were looking for it in the first place.
NELL GREENFIELDBOYCE, BYLINE: Astronomer Carl Sagan once said we were made up of stellar objects. He means literally The star’s burning core forms elements such as carbon, nitrogen and oxygen. But what about the heaviest elements on the periodic table – those like gold, platinum, uranium, plutonium?
ANTON WALLNER: These are the elements that we are still in the puzzle, and we don’t know exactly where and how much they were made on different sites.
GREENFIELDBOYCE: Anton Wallner is a physicist at the Australian National University. He leads an international team trying to find clues on how to build these elements, looking for examples that have come to the world recently. He said large star explosions or collisions would scatter elements. They can find their way to our world and combine with certain rocks.
WALLNER: So the idea is that we have samples of these extraterrestrial particles thousands or millions of years ago.
GREENFIELDBOYCE: The samples in this study were rocks from nearly a mile south of the Pacific Ocean.An oil exploration company was pulled up in the journal Science.Researchers said they found small amounts of iron and plutonium in unstable forms that do not persist. Brian Fields was an astronomer at the University of Illinois who was not part of the research team. He said the find was great.
BRIAN FIELDS: Right now we have very little material. After all, we are talking about hundreds of atoms here. But, you know, we should be grateful for that because it’s rebuilt from exploding stars.
GREENFIELDBOYCE: What kind of stellar explosion is ambiguous? What researchers see in rocks must be caused by something more than the death of a typical massive star, called a supernova explosion. It seems that more rare events will also have to be involved, such as collisions between neutron stars. They are very dense stars, small in size as a city. But has more mass than the sun
FIELDS: Knowing there is plutonium is amazing, even when it opens up new questions.I mean, that’s what you want – it’s to open up new questions. And now we have the opportunity to really learn more about it.
GREENFIELDBOYCE: The field says to help sort this out, it would be great to find other rare elements that are sent to Earth as stardust, Nell Greenfieldboyce, NPR News.
(SOUNDBITE OF SVEN LIBAEK’S “MUSIC FOR EELS”) Transcript is provided by NPR, copyright NPR.