Form of energy in the sky that created a continuous circle

My son and I was outside enjoying the night sky. We were looking for consolations and noticed a what appeared to be a white Mass object in the sky. The mass object suddenly appeared to suddenly expand into a large circle that was continuously getting larger and larger and was coming toward us. We continue to watch it for about 5 minutes before my son got so scared he started to cry and beg me to go inside to get away from it. After going inside we no longer monitored it. I have watched the night sky throughout my life multiple times and have never witnessed anything like this at night time before ever.