I think the plural that you have, meteorshowers.org, is better. The plural seems more natural in my opinion.
As far as value, developing it into a minisite will definitely increase the value. I'd say with a nice minisite you might be able to get mid to high $XX (maybe low $XXX if you find an enthusiast). I think the value could be higher, I'm just struggling to see how one could monetize the domain. There aren't any bids on the keywords "meteor showers" so the traffic would probably have to be monetized in some other way.
Seems like a difficult domain, but not impossible. I feel that if you have the traffic, there has to be some way to monetize it.
thks to both of you for giving ur appraisals.i like meteor showers myself n saw it once on a very memorable day wif my loved one.. will figure how to develop it soon..keep posted..