Large bright sphere splitting into smaller ones and rotating

I'm reporting this for my friend. In her words: Came outside and was surveying the sky when I saw a bright sphere that was almost pulsating which seemed unusual. Kept watching and it continued to split into smaller lights that circled the larger sphere. They all seemed to rotate around each other at times occasionally joining and combining into one sphere. It went on for about a half hour or more before they joined a final time and the lights went out.