On a clear Arctic night, the sky can begin almost imperceptibly. A pale band appears above the horizon, faint enough to be mistaken for a cloud. Then it brightens. The band folds into curtains, rays climb toward the stars and green light be...
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The most spectacular sign of a geomagnetic storm can look almost supernatural. Green curtains ripple across the night sky, red light appears hundreds or even thousands of kilometres farther...
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Open a familiar rectangular world map and something strange happens to the planet. Greenland appears enormous, sometimes looking almost comparable to Africa. Russia stretches across the top...
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Taste a drop of seawater and the answer seems obvious: the ocean contains salt. The more interesting question is how it got there. There are no gigantic salt deposits steadily dissolving int...
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Seal a cat inside a box with a radioactive atom, a radiation detector and a mechanism capable of releasing poison. Arrange the experiment so that, after an hour, the atom has a 50 percent ch...
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When George Herbert, the 5th Earl of Carnarvon, died in Cairo on April 5, 1923, the timing was almost too perfect for a sensational story. Only months earlier he had stood with archaeologist...
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Look up on a clear night and the most obvious feature of the universe is not the stars. It is the darkness between them. That darkness seems perfectly ordinary, yet for centuries it posed a...
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It is one of those questions that sounds almost too simple to deserve a scientific explanation. Look up on a clear afternoon and the sky is blue. Yet that familiar color is the visible resul...
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Few astronomical discoveries have produced a nickname as irresistible as the “diamond planet.” About 41 light-years away in the constellation Cancer, 55 Cancri e is a super-Earth nearly twic...
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Imagine putting the entire Solar System on a cosmic scale: the eight planets, every known moon, the asteroids, comets, dwarf planets, dust and the enormous Sun. The result would be absurdly...
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