Comments on: Alien Worlds in SciFi Movies http://thespacewriter.com/wp/2010/01/18/alien-worlds-in-scifi-movies/ It's about astronomy and space science and everything they touch. Sat, 21 Jan 2012 00:34:16 +0000 hourly 1 By: Matt http://thespacewriter.com/wp/2010/01/18/alien-worlds-in-scifi-movies/comment-page-1/#comment-3615 Matt Sun, 06 Feb 2011 04:39:41 +0000 http://thespacewriter.com/wp/?p=3710#comment-3615 the planet that your refer to, the one which Pandora (in Avatar) seems to revolve around, could be a dead planet. It may not have a molten core, therefore no magnetic field. Much like how Mars is today. the planet that your refer to, the one which Pandora (in Avatar) seems to revolve around, could be a dead planet. It may not have a molten core, therefore no magnetic field. Much like how Mars is today.

]]> By: ccp http://thespacewriter.com/wp/2010/01/18/alien-worlds-in-scifi-movies/comment-page-1/#comment-2336 ccp Thu, 28 Jan 2010 17:30:30 +0000 http://thespacewriter.com/wp/?p=3710#comment-2336 Yup. I kind of alluded to that in the posting -- and now that I think about it, it's a good question as to whether or not Pandora could even exist. However, to get Io-like conditions, you also have to have another gravitational influence tugging at the world. In Io's case, it's also being tugged on by the gravitational influence of Europa, Ganymede, and Callisto. I don't recall seeing other worlds around Polyphemus. Even if there are none, you still have to contend with the pull of the larger planet on the smaller world. Perhaps it's breaking up and that explains those floating mountains -- although I seriously doubt that a world breaking up would have any such verdant landcape on both the world and the floating mountains. Another planetary mystery -- but great fun to speculate about and even learn a little about planetary science, no? Yup. I kind of alluded to that in the posting — and now that I think about it, it’s a good question as to whether or not Pandora could even exist. However, to get Io-like conditions, you also have to have another gravitational influence tugging at the world. In Io’s case, it’s also being tugged on by the gravitational influence of Europa, Ganymede, and Callisto. I don’t recall seeing other worlds around Polyphemus. Even if there are none, you still have to contend with the pull of the larger planet on the smaller world. Perhaps it’s breaking up and that explains those floating mountains — although I seriously doubt that a world breaking up would have any such verdant landcape on both the world and the floating mountains. Another planetary mystery — but great fun to speculate about and even learn a little about planetary science, no?

]]> By: Alex http://thespacewriter.com/wp/2010/01/18/alien-worlds-in-scifi-movies/comment-page-1/#comment-2335 Alex Thu, 28 Jan 2010 13:37:13 +0000 http://thespacewriter.com/wp/?p=3710#comment-2335 Also Pandora's proximity to its parent planet seem to suggest that it's close enough that it should experience tidal forces the likes of which Io undergoes in its orbit around Jupiter. So even worse, instead of a lush verdant paradise, we should be seeing a torn and hellish volcanic landscape. As pretty it is having Polyphemus hover overhead so close by, there's no escaping its certain very powerful gravity influence. Also Pandora’s proximity to its parent planet seem to suggest that it’s close enough that it should experience tidal forces the likes of which Io undergoes in its orbit around Jupiter. So even worse, instead of a lush verdant paradise, we should be seeing a torn and hellish volcanic landscape.

As pretty it is having Polyphemus hover overhead so close by, there’s no escaping its certain very powerful gravity influence.

]]> By: ccp http://thespacewriter.com/wp/2010/01/18/alien-worlds-in-scifi-movies/comment-page-1/#comment-2331 ccp Tue, 26 Jan 2010 18:26:02 +0000 http://thespacewriter.com/wp/?p=3710#comment-2331 I don't disagree with either of you on the points you raise. We don't know enough about the gas giants discovered so far to know what level of magnetic fields and radiation environments they have, but consider that if you have a gas giant, it probably will likely be structurally similar to Jupiter and Saturn -- i.e. layers of conducting material beneath the cloud tops, atmospheric activity (as seen in Pandora's primary by the giant red spot-like storm) that would interact; and conducting layers would imply magnetic fields -- large planets at this level will likely have large, powerful magnetic fields. And, if there's any source of charged particles, we'll have a radiation environment. Those particles could come from the star in the system. So, we should, at some level, assume some radiation environment. What it is and how it affects the pandora-like planet remains TBD. About Saturn's magnetosphere: I refer you to the Cassini mission site about it: http://www.esa.int/esaMI/Cassini-Huygens/SEMBJCHHZTD_0.html Saturn does have a strong magnetic field and an immense magnetosphere that's about a fifth of Jupiter's. It is in some ways more similar to Earth's, and it does trap radiation belt particles, and these particles reach levels similar to those of the terrestrial magnetosphere. That does imply that any world near a Saturn-like world could be affected, but that would depend on the strength of the field, etc. I like the point about the native flora and fauna being a danger to humans. Cameron doesn't really address that, but it's interesting that he addresses the CO2 atmosphere and its effect. I don’t disagree with either of you on the points you raise. We don’t know enough about the gas giants discovered so far to know what level of magnetic fields and radiation environments they have, but consider that if you have a gas giant, it probably will likely be structurally similar to Jupiter and Saturn — i.e. layers of conducting material beneath the cloud tops, atmospheric activity (as seen in Pandora’s primary by the giant red spot-like storm) that would interact; and conducting layers would imply magnetic fields — large planets at this level will likely have large, powerful magnetic fields. And, if there’s any source of charged particles, we’ll have a radiation environment. Those particles could come from the star in the system. So, we should, at some level, assume some radiation environment. What it is and how it affects the pandora-like planet remains TBD.

About Saturn’s magnetosphere: I refer you to the Cassini mission site about it: http://www.esa.int/esaMI/Cassini-Huygens/SEMBJCHHZTD_0.html

Saturn does have a strong magnetic field and an immense magnetosphere that’s about a fifth of Jupiter’s. It is in some ways more similar to Earth’s, and it does trap radiation belt particles, and these particles reach levels similar to those of the terrestrial magnetosphere. That does imply that any world near a Saturn-like world could be affected, but that would depend on the strength of the field, etc.

I like the point about the native flora and fauna being a danger to humans. Cameron doesn’t really address that, but it’s interesting that he addresses the CO2 atmosphere and its effect.

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