From: Martin Shough <parcellular.nul> Date: Wed, 13 Mar 2013 15:02:09 -0000 Archived: Thu, 14 Mar 2013 09:28:39 -0500 Subject: Re: We Don't Understand... >From: Gerald O'Connell <goc.nul> >To: <post.nul> >Date: Wed, 13 Mar 2013 13:08:29 -0000 >Subject: Re: We Don't Understand... <snip> >One wonders, for example, how the earth/moon system might look >from these sort of distances. Perhaps some of the 'megaplanets' >that we are starting to see will turn out to be similar or more >complex systems. >Do any listers have a feel for whether current observations are >sufficiently finely tuned to support this type of distinction? >Or, to be more precise, has the data analysis even asked the >question? That's an interesting question, Gerald. It does seem to be assumed that these masses are single bodies. Are there cases where we have a planet detected both gravitationally and optically? In such a case a known brightness and a known mass would limit the surface area and thereby the density for a range of albedos and might serve to discriminate a composite system of many moons (or a cloud of dust etc) from a solid planet. Maybe there is an argument which extrapolates from a few such confirmed cases to the generality? Note that these superjupiters are in the order of several thousand earth masses, which would imply a heck of a lot of moons. But I suppose we ought to expect moon systems like those we see in our solar system where a number of satellites carry a small fraction of the total mass/momentum, and there might well be more surprising arrangements out there. Anyway I looked up exomoons and found some references. It appears that using Kepler it might be possible, amazaingly, to detect moons by the small changes they cause in transit times, and "the hunt is on" already: http://www.cfa.harvard.edu/HEK/about_hek.html http://www.time.com/time/health/article/0,8599,2104376,00.html Martin Shough Listen to 'Strange Days... Indeed' - The PodCast At: http://www.virtuallystrange.net/ufo/sdi/program/ These contents above are copyright of the author and UFO UpDates - Toronto. They may not be reproduced without the express permission of both parties and are intended for educational use only.
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