Why did Aaron make the calf?

I wonder what was in the mind of Aaron in making the golden calf? Did he believe Moses might be dead as the other people did? Without Moses did he feel he had only his own wits to use in deciding how the people should be led? The fact that Aaron was among those who chose the Lord’s side when Moses free the line suggests that his foolish act was not done maliciously or as a deliberate attempt to separate himself from God.