Hey Stephen, I think you've answered my questions! Many thanks! The print in the larger view shows the whole frame, I'm sure. Also, it is possible I was so tired when I wrote the journal entry that I forgot that I had used my normal lens, and not the wide-angle that I mistakenly called a tele. The normal lens is 52 mm., which fits in with your estimate. The weather record is a wonderful item -- I am hoping I could quote you in the blog I'll put on line about Tuesday. I do feel you have figured it out. Very best wishes, Joe --- On Fri, 4/17/09, Stephen Peterson <summitek@mindspring.com> wrote: From: Stephen Peterson <summitek@mindspring.com> Subject: [Utah-astronomy] Joe's UFO-2 To: utah-astronomy@mailman.xmission.com Date: Friday, April 17, 2009, 5:05 PM Had fun this morning looking at Joe's UFO photo. The 2 vertical stars to the right of and below Acamar are separated by about 3 degrees. The height of the UFO is thus about 3 degrees. Perusal of archived weather data for 15 Sept 2001 0700Z show rain on the W. Colorado/ E. Utah border about the latitude of Moab. Call the distance about 60 miles from The Wedge. That distance and angle give a height of 3.14 mi or 16600' agl, a reasonable height for a thunder head. Doubling the distance would double the height. Thunder cannot be heard for more than about 10 miles. A typical lightning rate is 3-5 per min. I count 15-20 dark 'dots' suggesting a 3 to 7 minute exposure time. Most of the 'dots' have vertical bars above them but not all. If the image is more or less full a 35 mm frame then the lens would appear to be about 50-60mm focal length from the coverage angle and frame size. If it was the 28m then the image must have been cropped. From the 'strobing' it would appear that the lighting was fairly regular and/or the storm didn't move much during the photo.  Joe was on track by calling it thunder storm, I would agree that a T-storm is the most likely explanation. Steve _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com