domus_artemis at hotmail.com
Sat Dec 15 06:16:07 PST 2007
> Date: Sat, 15 Dec 2007 05:23:36 -0800> From: recursive_loop at yahoo.com> To: urth at lists.urth.net> Subject: Re: (urth) Cumaean???> > "Lune is a tricky subject. We know it LOOKS bigger than now. That may be because its closer. Why> its closer we don't know. Maybe Wolfe assumes it would be closer do to gravitational attraction,> but thats wrong, because the Moon is actually getting farther away from Earth. Maybe it was> intentionally "pushed" towards the earth? Why I can't possibly understand. Some people say that> its mass was increased. Maybe, but what for and how?"> > If it were terraformed, they might have pelted it with comets to build the atmosphere. That would> increase the mass. But they also might have pelted it with rocky or metal asteroids to build the> mass (and increase the gravity) to help retain that comet-pelting created atmosphere (speculation> here)
Acrually I though of that after writing the above comentary. I agree. If the mass of the moon was increased it was almost surely to contain the atmosphere. In fact, the moon probably generated its own atmosphere during its formation, but eventually lost it because its mass was not enough to trap it.
> As for moving it towards Earth...If you can terraform a moon, maybe you want to move it as well to> decrease travel time? Or because you need a better light source in the sky to help you read those> futuristic eInk eBooks?
Here I desagree. I don't think a society where interstelar travel is common (it spanned the whole galaxy we are told), abble to terraform and increase a celestial body's mass and put a black hole in the center of the Sun would have any problem with travel times between the Earth and Moon. Surely that is not the reason. Maybe the moon is getting closer because of alterations on the gravitational force at the solar system level due to the black hole in the center of the Sun? Seems more reasonable.
> > Moving it closer brings it closer to the Roche Limit. Cross that line and the Moon breaks up,> IIRC. I'm not sure where the Roche Limit is in the Earth-Moon system (looked through a few books> on the shelves, but haven't found it yet).
I dont know either, but it seems to me that that limit would be met before geting so close that the atmospheres would touch (as is told in the Book of the Short Sun). > > > > > ____________________________________________________________________________________> Looking for last minute shopping deals? > Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping> _______________________________________________> Urth Mailing List> To post, write urth at urth.net> Subscription/information: http://www.urth.net
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