Unexplained Circle of Light

What caused an unexplained circle of light to appear in this photo? Is it an orb?

Ever see a picture that had a large flashlight-like anomaly show up in it like this photographic example? Sent to us anonymously, this is a fine example of some of the oddities people find after taking images with their cameras. Is it a ghost? An orb? Did something reflect light from the sun such as a small particle very near to the lens? We're not sure...

"Not really a question but every picture taken in my house has orbs in it, and I thought this one was pretty cool." - Anonymous