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  • richardmitnick 1:38 pm on May 15, 2021 Permalink | Reply
    Tags: , , , , , , , The tiny traces of plutonium-244 were found in ocean crust alongside radioactive iron-60., The two isotopes are evidence of violent cosmic events in the vicinity of Earth millions of years ago.   

    From Australian National University (AU) : “Alien radioactive element prompts creation rethink” 

    ANU Australian National University Bloc

    From Australian National University (AU)

    14 May 2021

    1
    From NASA Spitzer Infrared Observatyory (US) and NASA Chandra X-ray Observatory (US), remnant of N132D. Credit: National Aeronautics Space Agency (US)/ JPL-Caltech (US) and Harvard Smithsonian Center for Astrophysics (US).

    The first-ever discovery of an extraterrestrial radioactive isotope on Earth has scientists rethinking the origins of the elements on our planet.

    The tiny traces of plutonium-244 were found in ocean crust alongside radioactive iron-60. The two isotopes are evidence of violent cosmic events in the vicinity of Earth millions of years ago.

    Star explosions, or supernovae create many of the heavy elements in the periodic table, including those vital for human life, such as iron, potassium and iodine.

    To form even heavier elements, such as gold, uranium and plutonium it was thought that a more violent event may be needed, such as two neutron stars merging.

    However, a study led by Professor Anton Wallner from The Australian National University (ANU) suggests a more complex picture.

    “The story is complicated – possibly this plutonium-244 was produced in supernova explosions or it could be left over from a much older, but even more spectacular event such as a neutron star detonation,” lead author of the study, Professor Wallner said.

    Any plutonium-244 and iron-60 that existed when the Earth formed from interstellar gas and dust over four billion years ago has long since decayed, so current traces of them must have originated from recent cosmic events in space.

    The dating of the sample confirms two or more supernova explosions occurred near Earth.

    “Our data could be the first evidence that supernovae do indeed produce plutonium-244,” Professor Wallner said

    “Or perhaps it was already in the interstellar medium before the supernova went off, and it was pushed across the solar system together with the supernova ejecta.”

    Professor Wallner also holds joint positions at the HZDR – Helmholtz Center Dresden-Rossendorf [Helmholtz-Zentrum Dresden-Rossendorf] (DE) and Dresden University of Technology [Technische Universität Dresden] (DE), and conducted this work with researchers from Australia, Israel, Japan, Switzerland and Germany.

    The VEGA accelerator at Australian Nuclear Science and Technology Organisation, (ANSTO) in Sydney was used to identify the tiny traces of the plutonium-244.

    The study has been published in Science.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    ANU Campus

    The Australian National University (ANU) is a national research university located in Canberra, the capital of Australia. Its main campus in Acton encompasses seven teaching and research colleges, in addition to several national academies and institutes.

    ANU is regarded as one of the world’s leading research universities, and is ranked as the number one university in Australia and the Southern Hemisphere by the 2021 QS World University Rankings. It is ranked 31st in the world by the 2021 QS World University Rankings, and 59th in the world (third in Australia) by the 2021 Times Higher Education.

    In the 2020 Times Higher Education Global Employability University Ranking, an annual ranking of university graduates’ employability, ANU was ranked 15th in the world (first in Australia). According to the 2020 QS World University by Subject, the university was also ranked among the top 10 in the world for Anthropology, Earth and Marine Sciences, Geography, Geology, Philosophy, Politics, and Sociology.

    Established in 1946, ANU is the only university to have been created by the Parliament of Australia. It traces its origins to Canberra University College, which was established in 1929 and was integrated into ANU in 1960. ANU enrolls 10,052 undergraduate and 10,840 postgraduate students and employs 3,753 staff. The university’s endowment stood at A$1.8 billion as of 2018.

    ANU counts six Nobel laureates and 49 Rhodes scholars among its faculty and alumni. The university has educated two prime ministers, 30 current Australian ambassadors and more than a dozen current heads of government departments of Australia. The latest releases of ANU’s scholarly publications are held through ANU Press online.

    University centres

    There are individual research centres connected to the University.

    Asia Pacific College of Diplomacy
    Crawford School of Economics and Government
    Australian Primary Health Care Research Institute
    Centre for Aboriginal Economic Policy Research
    Centre for Applied Philosophy and Public Ethics
    Centre for Cross-Cultural Research, 1997–2008?, an ARC Centre of Excellence
    Centre for Mental Health Research
    Centre for the Public Awareness of Science
    Centre for Sustainable Energy Systems
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    National Graduate School of Management
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  • richardmitnick 8:01 am on May 14, 2021 Permalink | Reply
    Tags: , , , , , , , , The tiny traces of plutonium-244 were found in ocean crust alongside radioactive iron-60.   

    From Australian National University (AU) and From Science Alert (AU) : “Alien radioactive element prompts creation rethink” 

    ANU Australian National University Bloc

    From Australian National University (AU)

    and

    ScienceAlert

    From Science Alert (AU)

    From Australian National University (AU)
    14 May 2021

    1
    National Aeronautics Space Agency (US) JPL-Caltech (US)/Harvard Smithsonian Center for Astrophysics (US).

    The first-ever discovery of an extraterrestrial radioactive isotope on Earth has scientists rethinking the origins of the elements on our planet.

    The tiny traces of plutonium-244 were found in ocean crust alongside radioactive iron-60. The two isotopes are evidence of violent cosmic events in the vicinity of Earth millions of years ago.

    Star explosions, or supernovae create many of the heavy elements in the periodic table, including those vital for human life, such as iron, potassium and iodine.

    To form even heavier elements, such as gold, uranium and plutonium it was thought that a more violent event may be needed, such as two neutron stars merging.

    However, a study led by Professor Anton Wallner from The Australian National University (ANU) suggests a more complex picture.

    “The story is complicated – possibly this plutonium-244 was produced in supernova explosions or it could be left over from a much older, but even more spectacular event such as a neutron star detonation,” lead author of the study, Professor Wallner said.

    Any plutonium-244 and iron-60 that existed when the Earth formed from interstellar gas and dust over four billion years ago has long since decayed, so current traces of them must have originated from recent cosmic events in space.

    The dating of the sample confirms two or more supernova explosions occurred near Earth.

    “Our data could be the first evidence that supernovae do indeed produce plutonium-244,” Professor Wallner said

    “Or perhaps it was already in the interstellar medium before the supernova went off, and it was pushed across the solar system together with the supernova ejecta.”

    Professor Wallner also holds joint positions at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Dresden University of Technology [Technische Universität Dresden] (DE) in Germany, and conducted this work with researchers from Australia, Israel, Japan, Switzerland and Germany.

    The VEGA accelerator at Australian Nuclear Science and Technology Organisation, (ANSTO) in Sydney (AU) was used to identify the tiny traces of the plutonium-244.

    3
    VEGA accelerator. Credit: ANSTO .

    The study has been published in Science.

    From Science Alert (AU)
    14 MAY 2021
    MIKE MCRAE

    2
    Credit: MEHAU KULYK/Brand X Pictures/Getty Images.

    Far down in the periodic table you’ll find a list of heavy elements born in chaos.

    The kind of chaos you might find in an exploding star perhaps, or a collision between two neutron stars.

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

    We’d expect to see many heavyweight elements in the swirl of dust and gas that formed our planet eons ago – but most should have decayed into more stable forms long before now. So finding examples in Earth’s crust close to the surface today raises some interesting questions.

    The finding could tell us a thing or two about cataclysmic cosmic events taking place within a few hundred light-years from Earth, and relatively recently in our geological history. It could also shine a light on the way atomic heavyweights form.

    You see, building atoms takes a lot of energy. Protons can be squeezed into helium under the kind of gravity you’d find in a star, but stellar fusion will only take you so far. To build a chunky behemoth such as plutonium, you’ll need the kind of energy that can deliver a machine-gun burst of neutrons.

    There are a few conditions in the Universe under which this ‘rapid neutron capture’, or r-process, can occur, including supernovae and neutron star mergers.

    Over the history of the Universe, plenty of stars have crashed and popped to spill a thick dust of iron, uranium, plutonium, gold, and other fat atoms throughout the galaxy. So it’s to be expected that planets like Earth would have scooped up a good amount of them.

    But not all elements are born the same. Variations in the number of their neutrons make some more stable than others. Iron 60, for example, is a ‘blink and you’ll miss it’ kind of isotope if you view it on the cosmic scale, with a half-life of just 2.6 million years before it decays into nickel.

    Finding this short-lived isotope on our planet today – especially in the crust, just out of reach of modern artificial processes – would imply a relatively recent delivery of iron fresh from the cosmos.

    Iron 60 has appeared in rock samples before, dating back just a couple of million years. It’s also been seen in materials brought back from the lunar surface.

    But to get a good sense of the specific kind of r-process that produced these specimens, it would pay to see what other isotopes rained down with them.

    Physicist Anton Wallner from the Australian National University led a team of researchers in search of new samples of iron 60 to see if they could identify isotopes of other heavy elements close by.

    What they found was plutonium 244, an isotope with a half-life of just over 80 million years – stable for plutonium, but hardly the kind of element you’d expect to stick around since our planet came together 4.5 billion years ago.

    In all, the team discovered two distinct influxes of iron 60 which had to have arrived within the past 10 million years. Both samples were accompanied by small but significant quantities of plutonium 244, each in a similar ratio.

    Finding them together adds more detail than finding either apart. The amount of plutonium in them is lower than would be expected if supernovae were primarily responsible for their production, pointing to contributions from other r-processes.

    Exactly what was behind this particular sprinkle of alien space dust is left up to our imagination for now.

    “The story is complicated,” says Wallner.

    “Possibly this plutonium-244 was produced in supernova explosions or it could be left over from a much older, but even more spectacular event such as a neutron star detonation.”

    By measuring their respective radioactive fuses and making a few assumptions on the astrophysics behind their distribution, the researchers speculate the production of iron 60 is compatible with two to four supernova events going off between 50 and 100 parsecs (around 160 and 330 light years) of Earth.

    This isn’t the first time iron 60 has indicated a supernova taking place perilously close by in recent history.

    By looking at the isotope in connection with other elements, we could slowly build a signature that tells us more about the crash-bang conditions of our neighborhood in the millions of years before humans started to pay close attention.

    It’ll take more hunting for alien isotopes, though.

    “Our data could be the first evidence that supernovae do indeed produce plutonium-244,” says Wallner.

    “Or perhaps it was already in the interstellar medium before the supernova went off, and it was pushed across the Solar System together with the supernova ejecta.”

    This research was published in Science [above].

    See the full Australian National University (AU) article here .

    See the full Science Alert article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ANU Campus

    Australian National University (AU) is a world-leading university in Australia’s capital city, Canberra. Our location points to our unique history, ties to the Australian Government and special standing as a resource for the Australian people.

    Our focus on research as an asset, and an approach to education, ensures our graduates are in demand the world-over for their abilities to understand, and apply vision and creativity to addressing complex contemporary challenges.

    Australian National University (AU) is regarded as one of the world’s leading research universities, and is ranked as the number one university in Australia and the Southern Hemisphere by the 2021 QS World University Rankings. It is ranked 31st in the world by the 2021 QS World University Rankings, and 59th in the world (third in Australia) by the 2021 Times Higher Education.

    In the 2020 Times Higher Education Global Employability University Ranking, an annual ranking of university graduates’ employability, Australian National University (AU) was ranked 15th in the world (first in Australia). According to the 2020 QS World University by Subject, the university was also ranked among the top 10 in the world for Anthropology, Earth and Marine Sciences, Geography, Geology, Philosophy, Politics, and Sociology.

    Established in 1946, ANU is the only university to have been created by the Parliament of Australia. It traces its origins to Canberra University College, which was established in 1929 and was integrated into Australian National University (AU) in 1960. Australian National University (AU) enrolls 10,052 undergraduate and 10,840 postgraduate students and employs 3,753 staff. The university’s endowment stood at A$1.8 billion as of 2018.

    Australian National University (AU) counts six Nobel laureates and 49 Rhodes scholars among its faculty and alumni. The university has educated two prime ministers, 30 current Australian ambassadors and more than a dozen current heads of government departments of Australia. The latest releases of ANU’s scholarly publications are held through ANU Press online.

     
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