short answer: round things made out of lights and plastic cups.
long answer: Sparkleballs popped up in the 1970s, hanging from RVs in campgrounds, over playroom pingpong tables, and outside homes at Christmas. They may have been inspired by styrofoam coffee cup Bubble Lamps, which were a big craft thing back then.
Sparkleballs were made of Solo cups melted together with a soldering iron. Today new methods of connecting the cups have replaced burning plastic, and all kinds of cups and lights and shapes are used. (In Italy sparkleball snowmen are big at holidays.) However, all sparkleballs are built by people. Nothing commercial has ever fully replicated a sparkleball.
No one knows who invented sparkleballs or where the first one was made. One couple kept a sparkleball going for 27 years, which is pretty amazing. And in Fullerton, California, neighbors hang over 500 sparkleballs during the holidays!
The Wikipedia sparkleball definition will tell you a bit more :)
• Make your own Original Sparkleball.
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