Earth is protected from the constant streaming solar wind of radiation by its magnetosphere. Venus, however, has no such luck. A barren, inhospitable planet, with an atmosphere so dense that spacecraft landing there are crushed within hours, Venus has no magnetic protection. Researchers recently discovered that a common space weather phenomenon on the outskirts of Earth’s magnetic bubble, the magnetosphere, has much larger repercussions for Venus. The giant explosions, called hot flow anomalies, can be so large at Venus that they’re bigger than the entire planet and they can happen multiple times a day.
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Astronomers have discovered huge clouds of gas orbiting supermassive black holes at the centers of galaxies. Once thought to be a relatively uniform, fog-like ring, the accreting matter instead forms clumps dense enough to intermittently dim the intense radiation blazing forth as these enormous objects condense and consume matter, they report in a paper to be published in the Monthly Notices of the Royal Astronomical Society, available online now.
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On 7 June 2011, the biggest ejection of material ever observed erupted from the surface of the Sun (see video below). Over the days that followed, the plasma belched out by the Sun made its way out into space. But most of the material propelled up from the Sun’s surface quickly fell back towards our star’s surface. Researchers at University College London have studied the behaviour of the Sun's coronal mass ejections, explaining for the first time the details of how these huge eruptions behave as they fall back onto the Sun’s surface. In the process, they have discovered that coronal mass ejections have a surprising twin in the depths of space: the tendrils of gas in the Crab Nebula, which lie 6500 light-years away and are millions of times larger.
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A paper published in EPJ H provides the first English translation and an analysis of one of Albert Einstein’s little-known papers, “On the cosmological problem of the general theory of relativity.” Published in 1931, it features a forgotten model of the universe, while refuting Einstein’s own earlier static model of 1917. In this paper, Einstein introduces a cosmic model in which the universe undergoes an expansion followed by a contraction. This interpretation contrasts with the monotonically expanding universe of the widely known Einstein-de Sitter model of 1932.
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The Milky Way galaxy – our own cosmic neighborhood – forms one star the mass of Earth’s own sun each year. Massive AzTEC-3, the second-most-distant one of its kind known to humanity, produces about five of our suns each Earth day, churning out a total of 1,800 solar masses annually. Such ancient massive star-bursting galaxies can be found by astronomers using modern, mountaintop telescopes like the National Science Foundation-funded Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile. This exceptional galaxy, which at present day is only slightly younger than the 13.8 billion-year-old universe, is named after the AzTEC-millimeter-wave camera on the James Clerk Maxwell Telescope – through which it was initially found.
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An extraordinary jet trailing behind a runaway pulsar is seen in this composite image that contains data from NASA's Chandra X-ray Observatory (purple), radio data from the Australia Compact Telescope Array (green), and optical data from the 2MASS survey (red, green, and blue). The pulsar - a spinning neutron star - and its tail are found in the lower right of this image. The tail stretches for 37 light years , making it the longest jet ever seen from an object in the Milky Way galaxy.
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The highly distorted supernova remnant, called W49B, is about a thousand years old, as seen from Earth, and is at a distance of about 26,000 light years away shown in the image above may contain the most recent black hole formed in the Milky Way galaxy. The image combines X-rays from NASA's Chandra X-ray Observatory in blue and green, radio data from the NSF's Very Large Array in pink, and infrared data from Caltech's Palomar Observatory in yellow.
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The idea has been hotly debated among scientists for the past 20 years, ever since Viking Orbiter images revealed possible ancient shorelines near the pole. Later findings even suggested that the primordial ocean--dubbed Oceanus Borealis--could have covered a third of the planet.
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In a speech at the 2007 Venice Film Festival at special screening of his seminal noir thriller Blade Runner, Sir Ridley Scott, the legendary director of Alien, announced that he believes that science-fiction as a genre is dead.
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NASA trained several pairs of eyes on Saturn as the planet put on a dancing light show at its poles. While NASA's Hubble Space Telescope, orbiting around Earth, was able to observe the northern auroras in ultraviolet wavelengths, NASA's Cassini spacecraft, orbiting around Saturn, got complementary close-up views in infrared, visible-light and ultraviolet wavelengths. Cassini could also see northern and southern parts of Saturn that don't face Earth. The result is a kind of step-by-step choreography detailing how the auroras move, showing the complexity of these auroras and how scientists can connect an outburst from the sun and its effect on the magnetic environment at Saturn.
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