When the people realized that Moses was taking forever in coming down off the mountain, they rallied around Aaron and said, "Do something. Make gods for us who will lead us. That Moses, the man who got us out of Egypt - who knows what's happened to him?"
So Aaron told them, "Take off the gold rings from the ears of your wives and sons and daughters and bring them to me."
They all did it; they removed the gold rings from their ears and brought them to Aaron.
He took the gold from their hands and cast it in the form of a calf, shaping it with an engraving tool. The people responded with enthusiasm: "These are your gods, O Israel, who brought you up from Egypt!"
Aaron, taking in the situation, built an altar before the calf. Aaron then announced, "Tomorrow is a feast day to God!"
Early the next morning, the people got up and offered Whole-Burnt-Offerings and brought Peace-Offerings. The people sat down to eat and drink and then began to party. It turned into a wild party!