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Category: Astronomy/cosmology

Supernovae blasts struck the Earth 3 million and 7 million years ago

Supernovae blasts struck the Earth 3 million and 7 million years ago

Universe Today reports: A recent study examines how the Earth was hit by blasts from supernovae (plural form of supernova (SN)) that occurred 3 million years ago (Mya) and 7 Mya with the goal of ascertaining the distances of where these blasts originated. Using the live (not decaying) radioactive isotope 60-Fe, which is produced from supernovae, a team of researchers at the University of Illinois was able to determine the approximate astronomical distances to the blasts, which they refer to…

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How NASA brought an asteroid to Earth

How NASA brought an asteroid to Earth

David W. Brown writes: On a brisk day in February, 2004, Dante Lauretta, an assistant professor of planetary science at the University of Arizona, got a call from Michael Drake, the head of the school’s Lunar and Planetary Laboratory. “I have Lockheed Martin in my office,” Drake said. “They want to fly a spacecraft to an asteroid and bring back a sample. Are you in?” The two men met that evening with Steve Price, then a director of business development…

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Our galaxy’s stars keep a record of its past

Our galaxy’s stars keep a record of its past

Rebecca Boyle writes: Late in the evening of October 5, 1923, Edwin Hubble sat at the eyepiece of the Hooker telescope at the Mount Wilson Observatory, atop the mountains overlooking the Los Angeles basin. He was observing an object in the northern sky. To the unaided eye, it was visible as a faint smudge. But through a telescope it sharpened into a brilliant ellipse called the Andromeda Nebula. To settle a debate about the size of the Milky Way —…

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Don’t expect a ‘theory of everything’ to explain everything

Don’t expect a ‘theory of everything’ to explain everything

Dennis Overbye writes: What good are the laws of physics if we can’t solve the equations that describe them? That was the question that occurred to me on reading an article in The Guardian by Andrew Pontzen, a cosmologist at University College London who spends his days running computer simulations of black holes, stars, galaxies and the birth and growth of the universe. His point was that he and the rest of us are bound to fail. “Even if we…

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Back to New Jersey, where the universe began

Back to New Jersey, where the universe began

Dennis Overbye writes: On a field just below the summit of Crawford Hill, the highest point in Monmouth County, N.J., almost within sight of the skyscrapers of Manhattan, sits a cluster of shacks and sheds. Next to them is the Holmdel Horn Antenna, a radio telescope somewhat resembling the scoop of a giant steam shovel: an aluminum box 20 feet square at the mouth and tapering to an eight-inch opening, through which the radio waves are funneled into the “cab,”…

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Will the universe ever stop expanding?

Will the universe ever stop expanding?

Sarah Scoles writes: From Earth, the night sky looks fairly static. Sure, the stars rotate from evening to evening, and the planets move among them. But from a terrestrial perspective, the celestial sphere appears essentially unchanging. Perception, though, is not reality: our eyeballs don’t hint that beyond nearby planets, stars and galaxies, everything is moving away from us. The universe is constantly expanding—at an ever faster rate. “When we say that the universe is expanding, we mean something pretty literal,”…

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Is there a crisis in cosmology?

Is there a crisis in cosmology?

Adam Frank and Marcelo Gleiser write: Not long after the James Webb Space Telescope began beaming back from outer space its stunning images of planets and nebulae last year, astronomers, though dazzled, had to admit that something was amiss. Eight months later, based in part on what the telescope has revealed, it’s beginning to look as if we may need to rethink key features of the origin and development of the universe. Launched at the end of 2021 as a…

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JWST spots giant black holes all over the early universe

JWST spots giant black holes all over the early universe

Charlie Wood writes: Years before she was even sure the James Webb Space Telescope would successfully launch, Christina Eilers started planning a conference for astronomers specializing in the early universe. She knew that if — preferably, when — JWST started making observations, she and her colleagues would have a lot to talk about. Like a time machine, the telescope could see farther away and farther into the past than any previous instrument. Fortunately for Eilers (and the rest of the…

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Have astronomers finally found a meteorite from outside the solar system?

Have astronomers finally found a meteorite from outside the solar system?

Astronomy reports: After an expedition that spent about 10 days scouring the ocean floor off Papua New Guinea with a magnetic sled, Harvard University astrophysicist Avi Loeb says he has collected more than 700 metallic spherules that are now undergoing detailed examination in his lab at Harvard as well as at least two other independent labs that he asked to help out. Loeb believes that many of these spherules, each less than a millimeter across (about the size of a…

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New finding boosts Panspermia, the theory that life on Earth originated in deep space

New finding boosts Panspermia, the theory that life on Earth originated in deep space

Lina Zeldovich writes: Floating in the middle of our galaxy, near the center of the Milky Way, inside a cloud of gas that swirls at the temperature of 100 Kelvin or -279.67 Fahrenheit, a molecule essential to life on Earth has just been discovered. It sounds inconceivable that such a level of cosmic cold could harbor anything remotely related to a living organism—and yet it does. In fact, without this molecule, humans—and all other breathing, growing things on the planet—would…

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James Webb Space Telescope prompts a rethink of how galaxies form

James Webb Space Telescope prompts a rethink of how galaxies form

Adam Mann writes: Katherine Whitaker was on a video call with colleagues last summer when NASA released the first pictures from the ultra-powerful James Webb Space Telescope (JWST). Among the many awe-inspiring images was one of a sliver of sky surrounding the galaxy cluster SMACS 0723: It was brimming with some of the oldest and most distant galaxies ever recorded. “We would zoom in and be like, ‘Oh wow,’ and ‘What the heck is that?’” recalls Whitaker, an astronomer at…

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A year of cosmic wonder with the James Webb Space Telescope

A year of cosmic wonder with the James Webb Space Telescope

The New York Times reports: By now, perhaps, we should be getting used to unreal images of the cosmos made with the James Webb Space Telescope. But a year after NASA released the cosmic observatory’s first imagery, the space agency has dropped yet another breathtaking snapshot of our universe. Wednesday’s image was Rho Ophiuchi, the closest nursery of infant stars in our cosmic backyard. Located a mere 390 light years away from Earth, this cloud complex is chock-full of stellar…

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The dark universe is waiting. What will the Euclid telescope reveal?

The dark universe is waiting. What will the Euclid telescope reveal?

The New York Times reports: At 11:12 a.m. on Saturday, the Euclid spacecraft launched into space on its mission to chart the history of our universe as far back as 10 billion years ago. The space telescope, built by the European Space Agency, will use its instruments to record more than a third of the extragalactic sky over the next six years, creating the most accurate three-dimensional map of the cosmos to date. Researchers plan to use Euclid’s map to…

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Neutrinos build a ghostly map of the Milky Way

Neutrinos build a ghostly map of the Milky Way

The New York Times reports: From ghostlike particles, astrophysicists have pieced together a new map of the galaxy we live in. For now, that map of the Milky Way is blurry and incomplete. But as more data is gathered, it will become clearer and will help illuminate galactic convulsions like the expanding remnants of exploded stars, providing clues to mysteries that are difficult to solve with only observations from conventional telescopes. “This is the first time we’ve seen our own…

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Scientists thrill at first hints of cosmic ‘hum’ from giant gravitational waves

Scientists thrill at first hints of cosmic ‘hum’ from giant gravitational waves

Scientific American reports: After nearly two decades of listening, astronomers are finally starting to “hear” the rumbles of gravitational waves they believe emanate from the behemoths of our universe: supermassive black holes. The result comes from a National Science Foundation–sponsored initiative known as the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). Since 2004 NANOGrav has monitored metronomelike flashes of light from a Milky Way–spanning network of dead stars known as pulsars. Forged from the hearts of exploding massive stars,…

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Radical new theory gives a very different perspective on what life is

Radical new theory gives a very different perspective on what life is

Science Alert reports: Biologists usually define ‘life’ as an entity that reproduces, responds to its environment, metabolizes chemicals, consumes energy, and grows. Under this model, ‘life’ is a binary state; something is either alive or not. This definition works reasonably well on planet Earth, with viruses being one notable exception. But if life is elsewhere in the universe, it may not be made of the same stuff as us. It might not look, move, or communicate like we do. How,…

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