Science museums have recently become important instruments of science education. Unlike schools and universities, which continue to be the chief centers of formal education and training for professional research, museums are resources for spontaneous discovery in an informal setting. Addressed to both the general public and to scholars, museums collectively have a mission that is complex and diverse. They are required to combine elementary education and exposure to basic concepts of science with collection and preservation of rare and sophisticated research materials. They must combine serious pedagogy with artful entertainment and offer something of interest to both the expert and the novice.