Word: sun
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Dates: during 1980-1989
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...evening around the Leuschner Observatory in Lafayette, Calif., a few enterprising rattlesnakes slither out to toast themselves on the asphalt parking lot, which retains the warmth of the sun long after the air has cooled. Inside, a 30-in. telescope begins a laborious computer-controlled search of the heavens, covering only a tiny patch of sky during the next six hours of darkness. And the following day, at the nearby University of California campus in Berkeley, Physicist Richard Muller, like a seer divining entrails, scrutinizes the new batch of video recordings from Lafayette. He seeks a sign...
...have punctuated the history of life on this planet. Every 26 million years or so, the theory holds, a rain of comets that lasts hundreds or thousands of centuries bombards the earth. The impact of some of the larger comets spews enough debris into the atmosphere to block the sun for months. As the skies darken, temperatures on the ground plummet and the majority of existing plant and animal species perish...
...take heart from the new catastrophe theories as well. For example, the double- star systems that make up the majority of stars in the galaxy were long thought to be too unstable to support planets that could settle into regular orbits and give rise to life. But if the sun is part of a celestial duet, says Raup, then "the whole evolutionary process may thrive on this kind of disturbance...
Galvanized by this radical proposal, researchers are hunting for an agent that could explain the apparent clockwork regularity of the celestial barrages. Some suggest that a companion star to the sun periodically comes close enough to nudge comets gravitationally out of their natural habitat--a cloud of comets that circles the sun far beyond the orbit of Pluto--sending them hurtling toward earth. Others assign that role to Planet X, while some insist that the slow, bobbing ride of the sun and its planets around the Milky Way galaxy is responsible. Whatever the details, declares Paleontologist J. John Sepkoski...
What is more, the restless tectonic plates spawn volcanic eruptions, which spew carbon dioxide into the air. The increase in atmospheric carbon dioxide results in a greenhouse effect, which traps the sun's energy, causing temperatures on land and in the sea to rise markedly. Conversely, crustal movement may allow frigid ocean currents from the poles to invade tropical waters, leading to a worldwide drop in temperatures. Those species that cannot adapt to the earth's erratic behavior simply succumb. To many paleontologists, as well as geologists, it seemed to make sense...