Many books cover permanent astronomical objects, but few consider transient, out-of-the-ordinary astronomical phenomena. This book covers a wide range of topics, from the partly-predictable to the totally unpredictable. At one end: of the scale, it gives advice on the best ways to observe meteors, and at the other end:, it describes the best methods for undertaking painstaking searches for new comets and supernovae. The book also includes material about phenomena that occur in the lower atmosphere, such as "ozone eaters", nacreous clouds, and solar and lunar halos.