2 very faint, circular, transparent, moving halos seen in Johannesburg, South Africa on a clear evening.Yesterday evening, I went outside to fetch a blanket off the washing line. The time must have been around 19:45 -20:00 pm and the skies were quite clear.As I approached the washing line, by shear chance I noticed 2 faint halos in the sky, which for a second I thought was just a halo/or blur around a star or light. There was a large circular (not oval) halo with a smaller circular halo within the larger one. The 2 halos were extremely faint and I had to focus very hard to see them.At this point, scared to bits, I ran inside the house to call my brother to see this – just in case I was going crazy or seeing things. When we came outside again the halos had moved somewhat, and my brother too had to focus very hard to see them.I ran inside again to call my girlfriend, (who was in the bedroom on the other side of the house), and when we came outside for the third time the Halo’s had moved again and after about seven seconds it was not visible anymore.I don’t know what I saw, but the 2 circles that I saw were invisible, i.e.: you could see the sky and stars inside/behind the 2 halo’s, whatever it was it was invisible or transparent. It is only due to the faint rings/halo’s around the 2 circles that I was able to see it. It also appeared to be nearby i.e.: it wasn’t in the distant atmosphere, or in space as such, like the stars. It seemed quite nearby. However I’m not sure about the distance as it’s quite deceiving at night.I did not take any pictures or recordings, but they would not have been visible on camera anyways. I can however re-draw, illustrate them quite accuratly, as I my occupation requires me to pay extreme attention to detail.Can anyone explain this, or tell me that this is a natural phenomenon that occurs in the summer skies at night, and I should not worry. Or did I really see an unidentified flying object, and should look out for more? Or . . . .