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Plutonium is generally thought of as an artificial element created by humans, primarily to make the pits of nuclear weapons, but naturally occurring plutonium can be found in ancient rocks. Plutonium 244 is the longest lived isotope of Plutonium, but it's not easy to make, and finding this specific isotope in interstellar dust grains laid down on the ocean floors tells us important things about the formation of the elements that make up the Earth.Based on this paper:60Fe and 244Pu deposited on Earth constrain the r-process yields of recent nearby supernovae A. Wallner et al

In its 4.5 billion year history, Earth has had to run the gauntlet. Numerous catastrophes have imperilled the planet, from massive impacts, to volcanic conflagrations, to frigid episodes of snowball Earth. Yet life persists. Among all of the hazards that threaten a planet, the most potentially calamitous might be a nearby star exploding as a supernova. When a massive enough star reaches the end of its life, it explodes as a supernova (SN). The hyper-energetic explosion can light up the sky for months, turning night into day for any planets close enough. If a planet is too close, it will...

In its 4.5 billion year history, Earth has had to run the gauntlet. Numerous catastrophes have imperilled the planet, from massive impacts, to volcanic conflagrations, to frigid episodes of snowball Earth. Yet life persists. Among all of the hazards that threaten a planet, the most potentially calamitous might be a nearby star exploding as a supernova. Whan a massive enough star reaches the end of its life, it explodes as a supernova. The hyper-energetic explosion can light up the sky for months, turning night into day for any planets close enough. If a planet is too close, it will be...

When humanity finally detected the collision between two neutron stars in 2017, we confirmed a long-held theory - in the energetic fires of these incredible explosions, elements heavier than iron are forged. And so, we thought we had an answer to the question of how these elements - including gold - propagated throughout the Universe. But a new analysis has revealed a problem. According to new galactic chemical evolution models, neutron star collisions don't even come close to producing the abundances of heavy elements found in the Milky Way galaxy today. "Neutron star mergers did not produce enough heavy elements...

Gold is an element, which means you can't make it through ordinary chemical reactions — though alchemists tried for centuries. To make the sparkly metal, you have to bind 79 protons and 118 neutrons together to form a single atomic nucleus. That's an intense nuclear fusion reaction. But such intense fusion doesn't happen frequently enough, at least not nearby, to make the giant trove of gold we find on Earth and elsewhere in the solar system. And a new study has found the most commonly-theorized origin of gold — collisions between neutron stars — can't explain gold's abundance either. So...

Researchers then scoured the globe for thin layers of radioactive isotopes in rock strata and in 1999 struck figurative gold: Samples from beneath the ocean revealed some hard metallic layers, known as ferromanganese crusts that form slowly over millions of years, containing iron-60, an isotope with a half-life of 2.6 million years -- so short that the material must be much younger than Earth. The iron-60 was in a stratum laid down 2.2 million years ago. Similar layers of iron-60 have since been found elsewhere in the oceans. Astronomers have also been scouring the skies for groups of stars that...

An international team of scientists has found evidence of a series of massive supernova explosions near our solar system, which showered Earth with radioactive debris. The scientists found radioactive iron-60 in sediment and crust samples taken from the Pacific, Atlantic and Indian Oceans. The iron-60 was concentrated in a period between 3.2 and 1.7 million years ago, which is relatively recent in astronomical terms, said research leader Dr Anton Wallner from The Australian National University (ANU). "We were very surprised that there was debris clearly spread across 1.5 million years," said Dr Wallner, a nuclear physicist in the ANU Research...

Martin Bizzarro of the University of Copenhagen and his colleagues set out to determine the amount of iron in the early solar system. To do so, they measured nickel-60, a decay product of iron-60, in eight meteorites known to have formed at different times during the first 3 million years of the solar system. The meteorites that formed more than about a million years after the start of the solar system contain significantly more nickel-60 than do those that formed earlier, the team found. In a neighborhood of young stars, only a supernova could have produced iron-60, the parent of...

Might also answer poser: 'If supernovae were popcorn...' NASA's Hubble telescope has spotted the most distant massive star explosion of its kind ever, one which could help boffins understand the very fabric of the universe. Hubble view of supernova SN Wilson The telescope picked out Supernova UDS10Wil, also known as SN Wilson, in the night sky. The star apparently blew up over 10 billion years ago, and the resulting light from the explosion took that long to reach Earth. Wilson is in the special class of Type Ia supernovae, which give astroboffins a consistent level of brightness that can be...

We exist, therefore we question. Or at least, that paraphrases (poorly) an old quote from an old scholar... We know the masses and general composition of the four inner (rocky) planets in our solar system, and from basic chemistry, we know the number of atoms in a gram of any material. Multiplying Avogadro's number x the mass of these four planets, dividing by a weighted average atomic weight for the materials in each planet, we get about 3 x 10^ 50 heavy nuclei produced since creation/the big bang. Take your pick, that's the number of atomic nuclei we have to...

About 2.6 million years ago, an oddly bright light arrived in the prehistoric sky and lingered there for weeks or months. It was a supernova some 150 light years away from Earth. Within a few hundred years, long after the strange light in the sky had dwindled, a tsunami of cosmic energy from that same shattering star explosion could have reached our planet and pummeled the atmosphere, touching off climate change and triggering mass extinctions of large ocean animals, including a shark species that was the size of a school bus. The effects of such a supernova—and possibly more than...

Amid efforts to find alien life, scientists have not yet confirmed the existence of an extraterrestrial civilization. Findings of a new study suggest this has something do with the element phosphorus lacking in the cosmos. Life-Giving PhosphorusPhosphorus is the 11th most common element on Earth, and it is fundamental to all living things. Phosphorus is one of only six chemical elements on our planet that organisms depend on. "[Phosphorus] helps form the backbone of the long chains of nucleotides that create RNA and DNA; it is part of the phospholipids in cell membranes; and is a building block of the...

For most of human history, the distant ‘celestial sphere’ was regarded as perfect and unchanging. Stars remained in place, planets moved predictably, and the few rogue comets were viewed as atmospheric phenomena. This began to change with the Danish astronomer Tycho Brahe’s observation of the supernova of 1572 – apparently, a new star – and his studies of the Great Comet of 1577, which he proved was actually a distant object. Nonetheless, the impression of permanence is strong. There are very few astronomical objects that noticeably vary to the naked eye: only the brightest comets, novae and supernovae. For observers...

Millions of years ago, a series of nearby supernovae sent radiation and debris raining down to Earth. The events left traces of radioactive iron-60 embedded in the sea floor and even on the Moon, and now, researchers are saying they may have had life-altering effects on the early inhabitants of our planet. At just hundreds of light-years away, two major stellar explosions may have spurred changes to the environment, and even increased the rates of cancer and mutation.

Certain types of supernovae, or exploding stars, are more diverse than previously thought, a University of Arizona-led team of astronomers has discovered. The results, reported in two papers published in the Astrophysical Journal, have implications for big cosmological questions, such as how fast the universe has been expanding since the Big Bang. Most importantly, the findings hint at the possibility that the acceleration of the expansion of the universe might not be quite as fast as textbooks say. The team, led by UA astronomer Peter A. Milne, discovered that type Ia supernovae, which have been considered so uniform that cosmologists...

White dwarfs are the burned-out cores of stars like our Sun. Astronomers have discovered a pair of white dwarfs spiraling into one another at breakneck speeds. Today, these white dwarfs are so near they make a complete orbit in just 13 minutes, but they are gradually slipping closer together. About 900,000 years from now - a blink of an eye in astronomical time - they will merge and possibly explode as a supernova. By watching the stars converge, scientists will test both Einstein's theory of general relativity and the origin of some peculiar supernovae.The two white dwarfs are circling...

SYDNEY: The universe's first stars blew small galaxies apart when they exploded, effectively quashing all nearby star formation, say Japanese astrophysicists. The theory, based on analytical calculations of the energy and disruptive effects of early supernovae, adds another piece to the puzzle of what the first stars were like and how they influenced galaxy formation. The first stars formed around 200 million years after the Big Bang in clumps of dark matter called dark matter haloes – the basic building blocks of galaxies. Running out of gas These stars were massive, probably 10 to 100 times bigger than the Sun....

A newly examined ice core shows what may be the chemical traces of supernovae that exploded a thousand years ago. Yuko Motizuki of the RIKEN research institute in Wako, Japan, and colleagues analysed the nitrate content of an ice core drilled at Dome Fuji station in Antarctica. Nitrate is produced in the atmosphere by nitrogen oxides, which in turn should be created by the gamma radiation from a supernova. Motizuki's group found high nitrate concentrations in three thin layers about 50 metres deep. Because snow gradually builds up into layers of ice, depth indicates age. After calibrating this icy calendar...

Astronomers from Cardiff University, in Wales, and the Royal Observatory, Edinburgh, Scotland, believe they have solved one of the long-standing mysteries of the Universe - the origins of cosmic dust. In the latest issue of the science journal Nature, they explain how they have found that some supernovae, or exploding stars, belch out huge quantities of this dust - a discovery which suggests that supernovae were responsible for producing the first solid particles in the Universe. Originally astronomers thought that dust was mostly made in the winds from cool, giant stars in the late stages of their lives. Cosmic dust...

LONDON (Reuters) - Supernovae, powerful and violent explosions of stars at the end of their lives, hold the key to a 10 billion-year-old mystery -- the origins of cosmic dust, astronomers said Wednesday. Scientists long believed that cosmic dust, the fine solid particles in space that are the building blocks of planets, was made in relatively cool, slow-burning normal stars and released in a stellar wind. But astronomers in England and Wales say they have discovered that some supernovae spew out huge amounts of dust, suggesting they are the source of the first cosmic particles in the Universe. "The origin...