were recently an unanounced spectacle. Skywatching is a blast. There are optical filters and sensors for most every possibility. Motion sensors might be better. Measuring dI/dt (change in intensity with time) might be a better measurement for separating moving meteors from fixed background than direct observation. That's what physicists do, if you can't measure something directly, measure it indirectly with lots of fancy math. This light pollution web page is neat; http://antwrp.gsfc.nasa.gov/apod/image/0011/earthlights_dmsp_big.jpg When we blotted out the night sky we lost our context. -----Original Message----- From: Austad, Jay [SMTP:austad at marketwatch.com] Sent: Sunday, November 18, 2001 2:54 PM To: 'tclug-list at mn-linux.org' Subject: [TCLUG] OT: leonids meteor shower Did anyone else go outside last night and take a look at the meteor shower? Around 3:30 it was cloudy so I didn't think I'd be able to see it, but I played some Halo on my roomie's Xbox for about an hour and the clouds had gone away. I was able to see about 1 every 5 seconds or so, with several bursts of 5 or 10 of them at once. And that was in Brooklyn park, not in the boonies. Also, since light pollution is such a problem near cities, I wonder if that pollution is mostly around a particular wavelength. If so, would it be possible to make a filter to look through that would not pass a particular range of wavelengths? I'm no physics expert, but something like this might be possible to improve the visibility of objects the sky near large cities. Jay _______________________________________________ Twin Cities Linux Users Group Mailing List - Minneapolis/St. Paul, Minnesota http://www.mn-linux.org tclug-list at mn-linux.org https://mailman.mn-linux.org/mailman/listinfo/tclug-list