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Old 08-17-2010, 05:29 PM
John DiFool John DiFool is offline
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Super-Earths and powered flight as we know it

I was reading the latest Sci Am issue, which had an article on Super-Earths, terrestrial/rocky planets with masses several times that of our own. I suddenly started wondering how powered flight would work on a planet with say 3x as much gravity. Would it need a proportinately thicker atmosphere to maintain lift against the pull of gravity? Would they end up resorting to blimps or dirigibles because powered winged flight would be too hazardous or inefficient? I.e. the wings would have to be huge, which means extra drag and hence slow unmanueverable planes. Parachutes likely would need to be bigger and more robust as well. Thoughts?
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Old 08-17-2010, 06:14 PM
Chronos Chronos is offline
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First off, a planet with three times the mass won't have three times the surface gravity, since it'll also be bigger, and hence the surface will be further from the center. Assuming the same average density as the Earth, three times the mass would only mean 1.44 times the surface gravity.

Second, you've also got to account for the thickness of the atmosphere. All things being equal, heavier planets will have thicker atmospheres, and thicker atmospheres will make flight easier, and anyway, the Earth has an extremely thin atmosphere for its mass.
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