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Category: Astronomy

The value of the Hubble Constant and the fate of the universe

The value of the Hubble Constant and the fate of the universe

Corey S Powell writes: What determines our fate? To the Stoic Greek philosophers, fate is the external product of divine will, ‘the thread of your destiny’. To transcendentalists such as Henry David Thoreau, it is an inward matter of self-determination, of ‘what a man thinks of himself’. To modern cosmologists, fate is something else entirely: a sweeping, impersonal physical process that can be boiled down into a single, momentous number known as the Hubble Constant. The Hubble Constant can be…

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The most detailed 3D map of the Universe ever made

The most detailed 3D map of the Universe ever made

Nature reports: A survey of the southern sky has reconstructed how mass is spread across space and time, in the biggest study of its kind. The data provide striking evidence that dark energy, the force that appears to be pushing the Universe to accelerate its expansion, has been constant throughout cosmic history. The Dark Energy Survey (DES) collaboration revealed its results in an online briefing on 27 May and in several papers posted online. The DES team observed the sky…

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Life deep underground and inside other worlds

Life deep underground and inside other worlds

Jordana Cepelewicz writes: Scientists poke and prod at the fringes of habitability in pursuit of life’s limits. To that end, they have tunneled kilometers below Earth’s surface, drilling outward from the bottoms of mine shafts and sinking boreholes deep into ocean sediments. To their surprise, “life was everywhere that we looked,” said Tori Hoehler, a chemist and astrobiologist at NASA’s Ames Research Center. And it was present in staggering quantities: By various estimates, the inhabited subsurface realm has twice the…

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Solar storms are back, threatening chaos around the world

Solar storms are back, threatening chaos around the world

The Associated Press reports: A few days ago, millions of tons of super-heated gas shot off from the surface of the sun and hurtled 90 million miles toward Earth. The eruption, called a coronal mass ejection, wasn’t particularly powerful on the space-weather scale, but when it hit the Earth’s magnetic field it triggered the strongest geomagnetic storm seen for years. There wasn’t much disruption this time — few people probably even knew it happened — but it served as a…

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Space junk is blocking our view of the stars, scientists say

Space junk is blocking our view of the stars, scientists say

Live Science reports: The night sky is becoming increasingly filled with shiny satellites and space junk that pose a significant threat to our view of the cosmos, as well as astronomical research, a new study warns. The researchers found that the more than 9,300 tons (8,440 metric tons) of space objects orbiting Earth, including inoperative satellites and chunks of spent rocket stages, increase the overall brightness of the night sky by more than 10% over large parts of the planet….

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How the Pentagon started taking UFO’s seriously

How the Pentagon started taking UFO’s seriously

Gideon Lewis-Kraus writes: Leslie Kean is a self-possessed woman with a sensible demeanor and a nimbus of curly graying hair. She lives alone in a light-filled corner apartment near the northern extreme of Manhattan, where, on the wall behind her desk, there is a framed black-and-white image that looks like a sonogram of a Frisbee. The photograph was given to her, along with chain-of-custody documentation, by contacts in the Costa Rican government; in her estimation, it is the finest image…

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How radio astronomy reveals the universe

How radio astronomy reveals the universe

Emily Levesque writes: If you ask an astronomer to choose the single most exciting picture in all of astronomy, many of us will point to a familiar orange ring. At a glance it may not look like much — a fuzzy glowing doughnut, bulging slightly at the bottom and, as of last month, streaked with curving lines — but in reality this unassuming circle is humanity’s first glimpse of a black hole, with the colors chosen not to mimic realism,…

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What makes Elon Musk and Carl Sagan worlds apart

What makes Elon Musk and Carl Sagan worlds apart

Shannon Stirone writes: There’s no place like home—unless you’re Elon Musk. A prototype of SpaceX’s Starship, which may someday send humans to Mars, is, according to Musk, likely to launch soon, possibly within the coming days. But what motivates Musk? Why bother with Mars? A video clip from an interview Musk gave in 2019 seems to sum up Musk’s vision—and everything that’s wrong with it. In the video, Musk is seen reading a passage from Carl Sagan’s book Pale Blue…

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Have we already been visited by aliens?

Have we already been visited by aliens?

Elizabeth Kolbert writes: On October 19, 2017, a Canadian astronomer named Robert Weryk was reviewing images captured by a telescope known as Pan-STARRS1 when he noticed something strange. The telescope is situated atop Haleakalā, a ten-thousand-foot volcanic peak on the island of Maui, and it scans the sky each night, recording the results with the world’s highest-definition camera. It’s designed to hunt for “near-Earth objects,” which are mostly asteroids whose paths bring them into our planet’s astronomical neighborhood and which…

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Astronomers get their wish, and a cosmic mystery deepens

Astronomers get their wish, and a cosmic mystery deepens

Natalie Wolchover writes: On December 3, humanity suddenly had information at its fingertips that people have wanted for, well, forever: the precise distances to the stars. “You type in the name of a star or its position, and in less than a second you will have the answer,” Barry Madore, a cosmologist at the University of Chicago and Carnegie Observatories, said on a Zoom call last week. “I mean …” He trailed off. “We’re drinking from a firehose right now,”…

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The surface of the moon is a galactic time capsule

The surface of the moon is a galactic time capsule

Paul Sutter writes: You wouldn’t know it by looking at it, but the moon is a time capsule. Its surface has been completely exposed to vacuum for almost 4.5 billion years; meanwhile, it has been soaked by particles from the sun and beyond the solar system. Those particles remain, buried under the lunar surface, providing a detailed record of the history of our solar system and even our entire galaxy. It’s all right there. We just need to dig it…

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How the first life on Earth survived its biggest threat — water

How the first life on Earth survived its biggest threat — water

Michael Marshall writes: On 18 February next year, a NASA spacecraft will plummet through the Martian atmosphere, fire its retro-rockets to break its fall and then lower a six-wheeled rover named Perseverance to the surface. If all goes according to plan, the mission will land in Jezero Crater, a 45-kilometre-wide gash near the planet’s equator that might once have held a lake of liquid water. Among the throngs of earthlings cheering on Perseverance, John Sutherland will be paying particularly close…

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Signs of recent volcanic eruption on Mars hint at habitats for life

Signs of recent volcanic eruption on Mars hint at habitats for life

The New York Times reports: Mars was once home to seas and oceans, and perhaps even life. But our neighboring world has long since dried up and its atmosphere has been blown away, while most activity beneath its surface has long ceased. It’s a dead planet. Or is it? Previous research has hinted at volcanic eruptions on Mars 2.5 million years ago. But a new paper suggests an eruption occurred as recently as 53,000 years ago in a region called…

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There could be 300 million or more potentially habitable worlds in our galaxy

There could be 300 million or more potentially habitable worlds in our galaxy

Science Alert reports: There are many unanswered questions about our place in the Universe. Why are we here? What is the likelihood of our existence? Could there be others like us out there in the galaxy? One of the numbers that could help us answer these questions is this: How many rocky planets like Earth are orbiting stars like the Sun at a temperate distance amenable to life as we know it? Now, we have an answer, based on data…

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‘Pristine’ extraterrestrial organic compounds found on meteorite may shed light on origin of life on Earth

‘Pristine’ extraterrestrial organic compounds found on meteorite may shed light on origin of life on Earth

Vice reports: On a dark winter night in 2018, hundreds of people across the Great Lakes region witnessed a radiant meteor brighten the skies. Mere days after the fireball streaked overhead on that night in January, scientists were able to track down precious pieces of the ancient space rock using weather radar reports. The scattered remnants of the object, known as the Hamburg meteorite, contain a “high diversity” of extraterrestrial organic compounds that are preserved “in a pristine condition,” according…

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What Earth owes to black holes

What Earth owes to black holes

Marina Koren writes: The first picture ever captured of a black hole, one situated in the center of another galaxy, was pretty blurry. Seen in silhouette, it appeared fuzzy, as did the ring of hot gas surrounding it. The reaction of the public did not necessarily match the unalloyed joy of astronomers accustomed to extracting cosmic wonders from lines in a graph. To anyone more familiar with black holes from epic space films, this one mostly looked like a flame-glazed…

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