MUFON 77503

{nd} Intense bright light extreme altitude moving due south to north July 4, 2016, 10:37 PM MDT Location: Worland, Wyoming, 44n 108W I am located about 6 miles out of town and was at my neighbor1s house enjoying the fireworks around the valley. At 10:37 PM, a bright light, white in color, caught my attention overhead. The sky was clear with possibly a very thin overcast and stars clearly shining through and no moon. My first thought was it might be fireworks but there was no 1trail1 and explosion and it was way too high. The object was about as bright as Venus at its brightest and several times larger. It moved slowly from due south to north covering approximately 20 degrees of arc. Next I thought it might a satellite or the ISS but unless they changed its orbit, the ISS doesn1t fly a polar orbit. This was definitely a polar orbital flight path. What makes me think there was a thin overcast is the light 1plumed1. The object itself got very bright and a 1halo1 effect surrounded it opening to about 1 degree or a little more than the diameter of a full Moon would appear on the horizon. The halo looked like it might be the exhaust of a rocket going away from me and after perhaps 10 1 15 seconds the object dimmed to a star point and disappeared. As for its location in the sky, it traversed roughly 15 1 20 degrees of arc 3 1 5 degrees west of celestial zenith and 5 south of zenith to about 15 degrees north of zenith. I tried finding information about any NASA launches but nothing came up for this timeframe. I Googled 1space launches July 4 20161 but nothing showed. Might this have been a vehicle launch into a higher orbit or something else along that line? What I do know is it was definitely not a meteor, comet, fireball or the infamous 1swamp gas1 of Michigan. There was no sound except from people around the valley firing off fireworks and by that hour only a few people were doing so anyway. Please let me know what you figure out. I am curious as to what we saw. I might have to invest in a 1smart phone1 because taking video with my 1dumb phone1 takes too many steps and I didn1t want to miss observing this thing; whatever it was. On a personal note, I am retired Air Force and an Air Force Navigator/Electronic Warfare Officer as well as a private pilot. I am also an amateur astronomer. Thank You [Name and title removed/cms/tg]
Source ID77503