Kim, I wasn't thinking of "toy balloons", mylar balloons come in a variety of colors and sizes, not just aluminized party favors. Raw mylar is transparent. Genuine, authentic "weather balloons" are available as surplus items, all you need is a credit card and an email address (or a phone). I've seen 8 footers and 12 footers for sale to the general public, larger might be available, but it's been awhile since I looked into it. If it was white, it wasn't a UFO. It was chasing Patrick McGoohan. He must have slipped off the island again... 2009/3/14 Kim <kimharch@cut.net>
Thanks for all your comments. Chuck, if you were referring to the mylar balloons one finds in grocery stores, then what I saw doesn’t fit. The shape changed as if a large partially deflated balloon were tumbling and being deformed by the wind. It was also white, not silver. It actually reminded me of the kind of weather balloon that Stephen Peterson says he observed in 1956, but I saw no payload. I wish I had had time to set up a telescope, but I only saw it for a minute or two.
Once from my home on west capitol hill in SLC I saw two indistinct and shadowy shapes in the sky above the downtown area. They were quite large and difficult to see, neither being illuminated nor reflecting much light. I was outside doing some urban astronomy with my 10-inch Newt, so I took a look through the scope. Only then could I see that they were very large bundles of helium balloons, apparently released from somewhere downtown. I looked carefully, but there were no lawn chairs attached.
Kim