Circle over Lake Elmo-Oakdale, MN

The report, as filed

While attending a small yard campfire, I sighted a perfect circle of blue-green/teal colored light. It resembled a fluorescent ring light fixture on a straight south-north path parallel, but just east of I-694. From my perspective, its altitude was 800 to 1200 feet, appearing to be the size of a 14 to 16 inch pizza pan in vertical position. As a former Navy pilot, I would estimate its speed equivalent to that of aircraft on approach to Holman Airport in St. Paul, just prior to entering the landing pattern. Earlier in the day, I observed a twin engine aircraft traveling in the opposite direction on a S/W course toward the metro area. The UFO I sighted appeared to be at a similar altitude and speed, and it never deviated its course, remaining in sight approximately 30 seconds. The skies were totally clear. I have never sighted anything like this before. I find it difficult to believe it was a drone, based on my current understanding of their development & application. Are there similar sighting reported in this area at around 10:30 PM?

Held as-reported from National UFO Reporting Center (record NUFORC #131037). Witness text is preserved verbatim, including its spelling; nothing is edited beyond formatting.