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#1
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08-11-2011, 03:13 PM
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 My Rank: MAJOR Poster Rank:11 Join Date: Jun 2009 Posts: 93,130
Contributions: 226
Mentioned: 91 Post(s) Quoted: 2009 Post(s)
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Earth May Not Have Needed a Moon
Simulations of Earth’s stability on its axis carried out by American astronomers have suggested that a moonless planet would still be able to support life. Researchers believe that the stabilising effect our large moon has on Earth’s rotation may not be as crucial as previously believed. Scientists have long thought that without the moon the tilt of Earth would shift over time, experiencing wide fluctuations in climate as the sun shines almost directly on of the poles, affecting the evolution of life.  But astronomers at the University of Idaho have shown that even without a moon, the tilt of Earth's would vary only about ten degrees, and the influence of other planets in the solar system could have kept a moonless Earth stable. The astronomers also suggest that moons are not needed for other planets in the universe to be potentially habitable, reports Nasa-sponsored Astrobiology Magazine. Compared to the moons of other planets, Earth’s is very large, being only around a hundred times smaller than its parent. In comparison, Mars is over 60million times bigger than its largest moon, Phobos. While Earth's moon does provide some stability, the new data reveals that the pull of other planets orbiting the sun particularly Jupiter, would keep Earth from swinging too wildly. Try that for size: Selected moons of the solar system, with the Earth for scale:  ‘Because Jupiter is the most massive, it really defines the average plane of the solar system,’ said Jason Barnes, one of the astronomers who made the discovery. Without a moon, Barnes and his colleagues worked out that Earth would only shift on its axis by ten to 20 degrees over a half a billion years. Changes of one to two degrees are thought to be partly responsible for the Ice Ages, but the astronomers believe while the shifts would have had an effect on climate 'it would not have precluded the development of large scale, intelligent life.’ The previously-held belief that a large moon was necessary for a constant tilt meant that only about 1 per cent of terrestrial planets would have a steady climate, said Barnes. ‘A large moon can stabilise (a planet) but in most cases, it's not needed,’ he says. |
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#5
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08-11-2011, 06:36 PM
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 Benevolent dictator Poster Rank:57 Arse fucker Join Date: May 2009 Posts: 25,643 Mentioned: 17 Post(s) Quoted: 1450 Post(s)
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Re: Earth May Not Have Needed a Moon
Still best it's there though, look at the impact craters on it. I'd rather the big ones hit the moon than hit us, and if our space agencies smarten up we can convert the moon into a real long term space station.
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