Huge orb recorded in Fort Collins Colorado

I've seen this too. I live in the foothills above Fort Collins and I see these things at least three or four times a week. Sometimes there are 2,3, or 4 orbs at the same time and in close proximity to one another. What called my attention to them is the fact that they fade and/or wink out. They're always below the cloud deck - so they can't be very high. No features to them that I can